Archive-Team
/
zfs
2
0
Fork 0
Code Issues Pull Requests Packages Projects Releases 103 Wiki Activity
zfs/include/spl/sys/rwlock.h

275 lines
7.0 KiB
C
Raw Normal View History

Make file headers conform to ZFS style standard No semantic changes. Change /************\ and \************/ to /* and */ Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
2017-10-04 16:33:43 +00:00
/*
Public Release Prep Updated AUTHORS, COPYING, DISCLAIMER, and INSTALL files. Added standardized headers to all source file to clearly indicate the copyright, license, and to give credit where credit is due.
2010-05-17 22:18:00 +00:00
* Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
* Copyright (C) 2007 The Regents of the University of California.
* Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
* Written by Brian Behlendorf <behlendorf1@llnl.gov>.
Go through and add a header with the proper UCRL number. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@114 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-05-26 04:38:26 +00:00
* UCRL-CODE-235197
*
Public Release Prep Updated AUTHORS, COPYING, DISCLAIMER, and INSTALL files. Added standardized headers to all source file to clearly indicate the copyright, license, and to give credit where credit is due.
2010-05-17 22:18:00 +00:00
* This file is part of the SPL, Solaris Porting Layer.
Refresh links to web site Update links to refer to the official ZFS on Linux website instead of @behlendorf's personal fork on github. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-05 01:26:55 +00:00
* For details, see <http://zfsonlinux.org/>.
Public Release Prep Updated AUTHORS, COPYING, DISCLAIMER, and INSTALL files. Added standardized headers to all source file to clearly indicate the copyright, license, and to give credit where credit is due.
2010-05-17 22:18:00 +00:00
*
* The SPL is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
Go through and add a header with the proper UCRL number. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@114 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-05-26 04:38:26 +00:00
*
Public Release Prep Updated AUTHORS, COPYING, DISCLAIMER, and INSTALL files. Added standardized headers to all source file to clearly indicate the copyright, license, and to give credit where credit is due.
2010-05-17 22:18:00 +00:00
* The SPL is distributed in the hope that it will be useful, but WITHOUT
Go through and add a header with the proper UCRL number. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@114 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-05-26 04:38:26 +00:00
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
Public Release Prep Updated AUTHORS, COPYING, DISCLAIMER, and INSTALL files. Added standardized headers to all source file to clearly indicate the copyright, license, and to give credit where credit is due.
2010-05-17 22:18:00 +00:00
* with the SPL. If not, see <http://www.gnu.org/licenses/>.
Make file headers conform to ZFS style standard No semantic changes. Change /************\ and \************/ to /* and */ Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
2017-10-04 16:33:43 +00:00
*/
Go through and add a header with the proper UCRL number. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@114 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-05-26 04:38:26 +00:00
Minor nit, SOLARIS should be SPL git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@17 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-02-28 00:52:31 +00:00
#ifndef _SPL_RWLOCK_H
Fix cstyle warnings This patch contains no functional changes. It is solely intended to resolve cstyle warnings in order to facilitate moving the spl source code in to the zfs repository. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #681
2018-02-07 19:49:38 +00:00
#define _SPL_RWLOCK_H
Initial commit. All spl source written up to this point wrapped in an initial reasonable autoconf style build system. This does not yet build but the configure system does appear to work properly and integrate with the kernel. Hopefully the next commit gets us back to a buildable version we can run the test suite against. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@1 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-02-26 20:36:04 +00:00
Reorganize /include/ to add a /sys/, this way we don't need to muck with #includes in existing Solaris style source to get it to find the right stuff. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@18 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-03-01 00:45:59 +00:00
#include <sys/types.h>
Update rwlocks to track owner to ensure correct semantics The behavior of RW_*_HELD was updated because it was not quite right. It is not sufficient to return non-zero when the lock is help, we must only do this when the current task in the holder. This means we need to track the lock owner which is not something tracked in a Linux semaphore. After some experimentation the solution I settled on was to embed the Linux semaphore at the start of a larger krwlock_t structure which includes the owner field. This maintains good performance and allows us to cleanly intergrate with the kernel lock analysis tools. My reasons: 1) By placing the Linux semaphore at the start of krwlock_t we can then simply cast krwlock_t to a rw_semaphore and pass that on to the linux kernel. This allows us to use '#defines so the preprocessor can do direct replacement of the Solaris primative with the linux equivilant. This is important because it then maintains the location information for each rw_* call point. 2) Additionally, by adding the owner to krwlock_t we can keep this needed extra information adjacent to the lock itself. This removes the need for a fancy lookup to get the owner which is optimal for performance. We can also leverage the existing spin lock in the semaphore to ensure owner is updated correctly. 3) All helper functions which do not need to strictly be implemented as a define to preserve location information can be done as a static inline function. 4) Adding the owner to krwlock_t allows us to remove all memory allocations done during lock initialization. This is good for all the obvious reasons, we do give up the ability to specific the lock name. The Linux profiling tools will stringify the lock name used in the code via the preprocessor and use that. Update rwlocks validated on: - SLES10 (ppc64) - SLES11 (x86_64) - CHAOS4.2 (x86_64) - RHEL5.3 (x86_64) - RHEL6 (x86_64) - FC11 (x86_64)
2009-09-25 21:14:35 +00:00
#include <linux/rwsem.h>
Update build system and packaging Minimal changes required to integrate the SPL sources in to the ZFS repository build infrastructure and packaging. Build system and packaging: * Renamed SPL_* autoconf m4 macros to ZFS_*. * Removed redundant SPL_* autoconf m4 macros. * Updated the RPM spec files to remove SPL package dependency. * The zfs package obsoletes the spl package, and the zfs-kmod package obsoletes the spl-kmod package. * The zfs-kmod-devel* packages were updated to add compatibility symlinks under /usr/src/spl-x.y.z until all dependent packages can be updated. They will be removed in a future release. * Updated copy-builtin script for in-kernel builds. * Updated DKMS package to include the spl.ko. * Updated stale AUTHORS file to include all contributors. * Updated stale COPYRIGHT and included the SPL as an exception. * Renamed README.markdown to README.md * Renamed OPENSOLARIS.LICENSE to LICENSE. * Renamed DISCLAIMER to NOTICE. Required code changes: * Removed redundant HAVE_SPL macro. * Removed _BOOT from nvpairs since it doesn't apply for Linux. * Initial header cleanup (removal of empty headers, refactoring). * Remove SPL repository clone/build from zimport.sh. * Use of DEFINE_RATELIMIT_STATE and DEFINE_SPINLOCK removed due to build issues when forcing C99 compilation. * Replaced legacy ACCESS_ONCE with READ_ONCE. * Include needed headers for `current` and `EXPORT_SYMBOL`. Reviewed-by: Tony Hutter <hutter2@llnl.gov> Reviewed-by: Olaf Faaland <faaland1@llnl.gov> Reviewed-by: Matthew Ahrens <mahrens@delphix.com> Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> TEST_ZIMPORT_SKIP="yes" Closes #7556
2018-02-16 01:53:18 +00:00
#include <linux/sched.h>
Prepare SPL repo to merge with ZFS repo This commit removes everything from the repository except the core SPL implementation for Linux. Those files which remain have been moved to non-conflicting locations to facilitate the merge. The README.md and associated files have been updated accordingly. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2018-02-15 01:01:15 +00:00
/* Linux kernel compatibility */
#if defined(CONFIG_PREEMPT_RT_FULL)
#define SPL_RWSEM_SINGLE_READER_VALUE (1)
#define SPL_RWSEM_SINGLE_WRITER_VALUE (0)
#elif defined(CONFIG_RWSEM_GENERIC_SPINLOCK)
#define SPL_RWSEM_SINGLE_READER_VALUE (1)
#define SPL_RWSEM_SINGLE_WRITER_VALUE (-1)
#else
#define SPL_RWSEM_SINGLE_READER_VALUE (RWSEM_ACTIVE_READ_BIAS)
#define SPL_RWSEM_SINGLE_WRITER_VALUE (RWSEM_ACTIVE_WRITE_BIAS)
#endif
/* Linux 3.16 changed activity to count for rwsem-spinlock */
#if defined(CONFIG_PREEMPT_RT_FULL)
#define RWSEM_COUNT(sem) sem->read_depth
#elif defined(HAVE_RWSEM_ACTIVITY)
#define RWSEM_COUNT(sem) sem->activity
/* Linux 4.8 changed count to an atomic_long_t for !rwsem-spinlock */
#elif defined(HAVE_RWSEM_ATOMIC_LONG_COUNT)
#define RWSEM_COUNT(sem) atomic_long_read(&(sem)->count)
#else
#define RWSEM_COUNT(sem) sem->count
#endif
#if defined(RWSEM_SPINLOCK_IS_RAW)
#define spl_rwsem_lock_irqsave(lk, fl) raw_spin_lock_irqsave(lk, fl)
#define spl_rwsem_unlock_irqrestore(lk, fl) \
raw_spin_unlock_irqrestore(lk, fl)
#define spl_rwsem_trylock_irqsave(lk, fl) raw_spin_trylock_irqsave(lk, fl)
#else
#define spl_rwsem_lock_irqsave(lk, fl) spin_lock_irqsave(lk, fl)
#define spl_rwsem_unlock_irqrestore(lk, fl) spin_unlock_irqrestore(lk, fl)
#define spl_rwsem_trylock_irqsave(lk, fl) spin_trylock_irqsave(lk, fl)
#endif /* RWSEM_SPINLOCK_IS_RAW */
#define spl_rwsem_is_locked(rwsem) rwsem_is_locked(rwsem)
Initial commit. All spl source written up to this point wrapped in an initial reasonable autoconf style build system. This does not yet build but the configure system does appear to work properly and integrate with the kernel. Hopefully the next commit gets us back to a buildable version we can run the test suite against. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@1 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-02-26 20:36:04 +00:00
typedef enum {
Use tab indent in rwlock.h Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 16:02:55 +00:00
RW_DRIVER = 2,
Add new lock types MUTEX_NOLOCKDEP, and RW_NOLOCKDEP When running a kernel with CONFIG_LOCKDEP=y, lockdep reports possible recursive locking in some cases and possible circular locking dependency in others, within the SPL and ZFS modules. When lockdep detects these conditions, it disables further lock analysis for all locks. This causes /proc/lock_stats not to reflect full information about lock contention, even in locks without dependency issues. This commit creates a new type of mutex, MUTEX_NOLOCKDEP. This mutex type causes subsequent attempts to take or release those locks to be wrapped in lockdep_off() and lockdep_on(). This commit also creates an RW_NOLOCKDEP type analagous to MUTEX_NOLOCKDEP. MUTEX_NOLOCKDEP and RW_NOLOCKDEP are also defined in zfs, in a commit to that repo, for userspace builds. Signed-off-by: Olaf Faaland <faaland1@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #480
2015-10-06 21:01:46 +00:00
RW_DEFAULT = 4,
RW_NOLOCKDEP = 5
Initial commit. All spl source written up to this point wrapped in an initial reasonable autoconf style build system. This does not yet build but the configure system does appear to work properly and integrate with the kernel. Hopefully the next commit gets us back to a buildable version we can run the test suite against. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@1 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-02-26 20:36:04 +00:00
} krw_type_t;
typedef enum {
Use tab indent in rwlock.h Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 16:02:55 +00:00
RW_NONE = 0,
RW_WRITER = 1,
RW_READER = 2
Initial commit. All spl source written up to this point wrapped in an initial reasonable autoconf style build system. This does not yet build but the configure system does appear to work properly and integrate with the kernel. Hopefully the next commit gets us back to a buildable version we can run the test suite against. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@1 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-02-26 20:36:04 +00:00
} krw_t;
rwsem use kernel provided owner when possible If CONFIG_RWSEM_SPIN_ON_OWNER is defined, rw_semaphore will have an owner field, so we don't need our own. Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 15:28:02 +00:00
/*
* If CONFIG_RWSEM_SPIN_ON_OWNER is defined, rw_semaphore will have an owner
* field, so we don't need our own.
*/
Update rwlocks to track owner to ensure correct semantics The behavior of RW_*_HELD was updated because it was not quite right. It is not sufficient to return non-zero when the lock is help, we must only do this when the current task in the holder. This means we need to track the lock owner which is not something tracked in a Linux semaphore. After some experimentation the solution I settled on was to embed the Linux semaphore at the start of a larger krwlock_t structure which includes the owner field. This maintains good performance and allows us to cleanly intergrate with the kernel lock analysis tools. My reasons: 1) By placing the Linux semaphore at the start of krwlock_t we can then simply cast krwlock_t to a rw_semaphore and pass that on to the linux kernel. This allows us to use '#defines so the preprocessor can do direct replacement of the Solaris primative with the linux equivilant. This is important because it then maintains the location information for each rw_* call point. 2) Additionally, by adding the owner to krwlock_t we can keep this needed extra information adjacent to the lock itself. This removes the need for a fancy lookup to get the owner which is optimal for performance. We can also leverage the existing spin lock in the semaphore to ensure owner is updated correctly. 3) All helper functions which do not need to strictly be implemented as a define to preserve location information can be done as a static inline function. 4) Adding the owner to krwlock_t allows us to remove all memory allocations done during lock initialization. This is good for all the obvious reasons, we do give up the ability to specific the lock name. The Linux profiling tools will stringify the lock name used in the code via the preprocessor and use that. Update rwlocks validated on: - SLES10 (ppc64) - SLES11 (x86_64) - CHAOS4.2 (x86_64) - RHEL5.3 (x86_64) - RHEL6 (x86_64) - FC11 (x86_64)
2009-09-25 21:14:35 +00:00
typedef struct {
Use tab indent in rwlock.h Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 16:02:55 +00:00
struct rw_semaphore rw_rwlock;
rwsem use kernel provided owner when possible If CONFIG_RWSEM_SPIN_ON_OWNER is defined, rw_semaphore will have an owner field, so we don't need our own. Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 15:28:02 +00:00
#ifndef CONFIG_RWSEM_SPIN_ON_OWNER
Use tab indent in rwlock.h Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 16:02:55 +00:00
kthread_t *rw_owner;
rwsem use kernel provided owner when possible If CONFIG_RWSEM_SPIN_ON_OWNER is defined, rw_semaphore will have an owner field, so we don't need our own. Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 15:28:02 +00:00
#endif
Add new lock types MUTEX_NOLOCKDEP, and RW_NOLOCKDEP When running a kernel with CONFIG_LOCKDEP=y, lockdep reports possible recursive locking in some cases and possible circular locking dependency in others, within the SPL and ZFS modules. When lockdep detects these conditions, it disables further lock analysis for all locks. This causes /proc/lock_stats not to reflect full information about lock contention, even in locks without dependency issues. This commit creates a new type of mutex, MUTEX_NOLOCKDEP. This mutex type causes subsequent attempts to take or release those locks to be wrapped in lockdep_off() and lockdep_on(). This commit also creates an RW_NOLOCKDEP type analagous to MUTEX_NOLOCKDEP. MUTEX_NOLOCKDEP and RW_NOLOCKDEP are also defined in zfs, in a commit to that repo, for userspace builds. Signed-off-by: Olaf Faaland <faaland1@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #480
2015-10-06 21:01:46 +00:00
#ifdef CONFIG_LOCKDEP
krw_type_t rw_type;
#endif /* CONFIG_LOCKDEP */
Update rwlocks to track owner to ensure correct semantics The behavior of RW_*_HELD was updated because it was not quite right. It is not sufficient to return non-zero when the lock is help, we must only do this when the current task in the holder. This means we need to track the lock owner which is not something tracked in a Linux semaphore. After some experimentation the solution I settled on was to embed the Linux semaphore at the start of a larger krwlock_t structure which includes the owner field. This maintains good performance and allows us to cleanly intergrate with the kernel lock analysis tools. My reasons: 1) By placing the Linux semaphore at the start of krwlock_t we can then simply cast krwlock_t to a rw_semaphore and pass that on to the linux kernel. This allows us to use '#defines so the preprocessor can do direct replacement of the Solaris primative with the linux equivilant. This is important because it then maintains the location information for each rw_* call point. 2) Additionally, by adding the owner to krwlock_t we can keep this needed extra information adjacent to the lock itself. This removes the need for a fancy lookup to get the owner which is optimal for performance. We can also leverage the existing spin lock in the semaphore to ensure owner is updated correctly. 3) All helper functions which do not need to strictly be implemented as a define to preserve location information can be done as a static inline function. 4) Adding the owner to krwlock_t allows us to remove all memory allocations done during lock initialization. This is good for all the obvious reasons, we do give up the ability to specific the lock name. The Linux profiling tools will stringify the lock name used in the code via the preprocessor and use that. Update rwlocks validated on: - SLES10 (ppc64) - SLES11 (x86_64) - CHAOS4.2 (x86_64) - RHEL5.3 (x86_64) - RHEL6 (x86_64) - FC11 (x86_64)
2009-09-25 21:14:35 +00:00
} krwlock_t;
Initial commit. All spl source written up to this point wrapped in an initial reasonable autoconf style build system. This does not yet build but the configure system does appear to work properly and integrate with the kernel. Hopefully the next commit gets us back to a buildable version we can run the test suite against. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@1 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-02-26 20:36:04 +00:00
Fix cstyle warnings This patch contains no functional changes. It is solely intended to resolve cstyle warnings in order to facilitate moving the spl source code in to the zfs repository. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #681
2018-02-07 19:49:38 +00:00
#define SEM(rwp) (&(rwp)->rw_rwlock)
Update rwlocks to track owner to ensure correct semantics The behavior of RW_*_HELD was updated because it was not quite right. It is not sufficient to return non-zero when the lock is help, we must only do this when the current task in the holder. This means we need to track the lock owner which is not something tracked in a Linux semaphore. After some experimentation the solution I settled on was to embed the Linux semaphore at the start of a larger krwlock_t structure which includes the owner field. This maintains good performance and allows us to cleanly intergrate with the kernel lock analysis tools. My reasons: 1) By placing the Linux semaphore at the start of krwlock_t we can then simply cast krwlock_t to a rw_semaphore and pass that on to the linux kernel. This allows us to use '#defines so the preprocessor can do direct replacement of the Solaris primative with the linux equivilant. This is important because it then maintains the location information for each rw_* call point. 2) Additionally, by adding the owner to krwlock_t we can keep this needed extra information adjacent to the lock itself. This removes the need for a fancy lookup to get the owner which is optimal for performance. We can also leverage the existing spin lock in the semaphore to ensure owner is updated correctly. 3) All helper functions which do not need to strictly be implemented as a define to preserve location information can be done as a static inline function. 4) Adding the owner to krwlock_t allows us to remove all memory allocations done during lock initialization. This is good for all the obvious reasons, we do give up the ability to specific the lock name. The Linux profiling tools will stringify the lock name used in the code via the preprocessor and use that. Update rwlocks validated on: - SLES10 (ppc64) - SLES11 (x86_64) - CHAOS4.2 (x86_64) - RHEL5.3 (x86_64) - RHEL6 (x86_64) - FC11 (x86_64)
2009-09-25 21:14:35 +00:00
static inline void
spl_rw_set_owner(krwlock_t *rwp)
{
rwsem use kernel provided owner when possible If CONFIG_RWSEM_SPIN_ON_OWNER is defined, rw_semaphore will have an owner field, so we don't need our own. Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 15:28:02 +00:00
/*
* If CONFIG_RWSEM_SPIN_ON_OWNER is defined, down_write, up_write,
* downgrade_write and __init_rwsem will set/clear owner for us.
*/
#ifndef CONFIG_RWSEM_SPIN_ON_OWNER
Don't take spin lock on rwlock owner The spin lock around rw_owner is completely unnecessary. The reason is that it is only modified in the down_write context. If you race against another thread modifying it, that means that you aren't holding the rwlock, so taking the spin lock don't eliminate the race. Also, we only check rw_owner in RW_WRITE_HELD because spl_rwsem_is_locked is unnecessary and might need to take spin lock. Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 13:55:06 +00:00
rwp->rw_owner = current;
rwsem use kernel provided owner when possible If CONFIG_RWSEM_SPIN_ON_OWNER is defined, rw_semaphore will have an owner field, so we don't need our own. Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 15:28:02 +00:00
#endif
Update rwlocks to track owner to ensure correct semantics The behavior of RW_*_HELD was updated because it was not quite right. It is not sufficient to return non-zero when the lock is help, we must only do this when the current task in the holder. This means we need to track the lock owner which is not something tracked in a Linux semaphore. After some experimentation the solution I settled on was to embed the Linux semaphore at the start of a larger krwlock_t structure which includes the owner field. This maintains good performance and allows us to cleanly intergrate with the kernel lock analysis tools. My reasons: 1) By placing the Linux semaphore at the start of krwlock_t we can then simply cast krwlock_t to a rw_semaphore and pass that on to the linux kernel. This allows us to use '#defines so the preprocessor can do direct replacement of the Solaris primative with the linux equivilant. This is important because it then maintains the location information for each rw_* call point. 2) Additionally, by adding the owner to krwlock_t we can keep this needed extra information adjacent to the lock itself. This removes the need for a fancy lookup to get the owner which is optimal for performance. We can also leverage the existing spin lock in the semaphore to ensure owner is updated correctly. 3) All helper functions which do not need to strictly be implemented as a define to preserve location information can be done as a static inline function. 4) Adding the owner to krwlock_t allows us to remove all memory allocations done during lock initialization. This is good for all the obvious reasons, we do give up the ability to specific the lock name. The Linux profiling tools will stringify the lock name used in the code via the preprocessor and use that. Update rwlocks validated on: - SLES10 (ppc64) - SLES11 (x86_64) - CHAOS4.2 (x86_64) - RHEL5.3 (x86_64) - RHEL6 (x86_64) - FC11 (x86_64)
2009-09-25 21:14:35 +00:00
}
static inline void
spl_rw_clear_owner(krwlock_t *rwp)
{
rwsem use kernel provided owner when possible If CONFIG_RWSEM_SPIN_ON_OWNER is defined, rw_semaphore will have an owner field, so we don't need our own. Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 15:28:02 +00:00
#ifndef CONFIG_RWSEM_SPIN_ON_OWNER
Don't take spin lock on rwlock owner The spin lock around rw_owner is completely unnecessary. The reason is that it is only modified in the down_write context. If you race against another thread modifying it, that means that you aren't holding the rwlock, so taking the spin lock don't eliminate the race. Also, we only check rw_owner in RW_WRITE_HELD because spl_rwsem_is_locked is unnecessary and might need to take spin lock. Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 13:55:06 +00:00
rwp->rw_owner = NULL;
rwsem use kernel provided owner when possible If CONFIG_RWSEM_SPIN_ON_OWNER is defined, rw_semaphore will have an owner field, so we don't need our own. Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 15:28:02 +00:00
#endif
Update rwlocks to track owner to ensure correct semantics The behavior of RW_*_HELD was updated because it was not quite right. It is not sufficient to return non-zero when the lock is help, we must only do this when the current task in the holder. This means we need to track the lock owner which is not something tracked in a Linux semaphore. After some experimentation the solution I settled on was to embed the Linux semaphore at the start of a larger krwlock_t structure which includes the owner field. This maintains good performance and allows us to cleanly intergrate with the kernel lock analysis tools. My reasons: 1) By placing the Linux semaphore at the start of krwlock_t we can then simply cast krwlock_t to a rw_semaphore and pass that on to the linux kernel. This allows us to use '#defines so the preprocessor can do direct replacement of the Solaris primative with the linux equivilant. This is important because it then maintains the location information for each rw_* call point. 2) Additionally, by adding the owner to krwlock_t we can keep this needed extra information adjacent to the lock itself. This removes the need for a fancy lookup to get the owner which is optimal for performance. We can also leverage the existing spin lock in the semaphore to ensure owner is updated correctly. 3) All helper functions which do not need to strictly be implemented as a define to preserve location information can be done as a static inline function. 4) Adding the owner to krwlock_t allows us to remove all memory allocations done during lock initialization. This is good for all the obvious reasons, we do give up the ability to specific the lock name. The Linux profiling tools will stringify the lock name used in the code via the preprocessor and use that. Update rwlocks validated on: - SLES10 (ppc64) - SLES11 (x86_64) - CHAOS4.2 (x86_64) - RHEL5.3 (x86_64) - RHEL6 (x86_64) - FC11 (x86_64)
2009-09-25 21:14:35 +00:00
}
static inline kthread_t *
rw_owner(krwlock_t *rwp)
{
rwsem use kernel provided owner when possible If CONFIG_RWSEM_SPIN_ON_OWNER is defined, rw_semaphore will have an owner field, so we don't need our own. Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 15:28:02 +00:00
#ifdef CONFIG_RWSEM_SPIN_ON_OWNER
Fix cstyle warnings This patch contains no functional changes. It is solely intended to resolve cstyle warnings in order to facilitate moving the spl source code in to the zfs repository. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #681
2018-02-07 19:49:38 +00:00
return (SEM(rwp)->owner);
rwsem use kernel provided owner when possible If CONFIG_RWSEM_SPIN_ON_OWNER is defined, rw_semaphore will have an owner field, so we don't need our own. Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 15:28:02 +00:00
#else
Fix cstyle warnings This patch contains no functional changes. It is solely intended to resolve cstyle warnings in order to facilitate moving the spl source code in to the zfs repository. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #681
2018-02-07 19:49:38 +00:00
return (rwp->rw_owner);
rwsem use kernel provided owner when possible If CONFIG_RWSEM_SPIN_ON_OWNER is defined, rw_semaphore will have an owner field, so we don't need our own. Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 15:28:02 +00:00
#endif
Update rwlocks to track owner to ensure correct semantics The behavior of RW_*_HELD was updated because it was not quite right. It is not sufficient to return non-zero when the lock is help, we must only do this when the current task in the holder. This means we need to track the lock owner which is not something tracked in a Linux semaphore. After some experimentation the solution I settled on was to embed the Linux semaphore at the start of a larger krwlock_t structure which includes the owner field. This maintains good performance and allows us to cleanly intergrate with the kernel lock analysis tools. My reasons: 1) By placing the Linux semaphore at the start of krwlock_t we can then simply cast krwlock_t to a rw_semaphore and pass that on to the linux kernel. This allows us to use '#defines so the preprocessor can do direct replacement of the Solaris primative with the linux equivilant. This is important because it then maintains the location information for each rw_* call point. 2) Additionally, by adding the owner to krwlock_t we can keep this needed extra information adjacent to the lock itself. This removes the need for a fancy lookup to get the owner which is optimal for performance. We can also leverage the existing spin lock in the semaphore to ensure owner is updated correctly. 3) All helper functions which do not need to strictly be implemented as a define to preserve location information can be done as a static inline function. 4) Adding the owner to krwlock_t allows us to remove all memory allocations done during lock initialization. This is good for all the obvious reasons, we do give up the ability to specific the lock name. The Linux profiling tools will stringify the lock name used in the code via the preprocessor and use that. Update rwlocks validated on: - SLES10 (ppc64) - SLES11 (x86_64) - CHAOS4.2 (x86_64) - RHEL5.3 (x86_64) - RHEL6 (x86_64) - FC11 (x86_64)
2009-09-25 21:14:35 +00:00
}
Add new lock types MUTEX_NOLOCKDEP, and RW_NOLOCKDEP When running a kernel with CONFIG_LOCKDEP=y, lockdep reports possible recursive locking in some cases and possible circular locking dependency in others, within the SPL and ZFS modules. When lockdep detects these conditions, it disables further lock analysis for all locks. This causes /proc/lock_stats not to reflect full information about lock contention, even in locks without dependency issues. This commit creates a new type of mutex, MUTEX_NOLOCKDEP. This mutex type causes subsequent attempts to take or release those locks to be wrapped in lockdep_off() and lockdep_on(). This commit also creates an RW_NOLOCKDEP type analagous to MUTEX_NOLOCKDEP. MUTEX_NOLOCKDEP and RW_NOLOCKDEP are also defined in zfs, in a commit to that repo, for userspace builds. Signed-off-by: Olaf Faaland <faaland1@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #480
2015-10-06 21:01:46 +00:00
#ifdef CONFIG_LOCKDEP
static inline void
spl_rw_set_type(krwlock_t *rwp, krw_type_t type)
{
rwp->rw_type = type;
}
static inline void
spl_rw_lockdep_off_maybe(krwlock_t *rwp) \
{ \
if (rwp && rwp->rw_type == RW_NOLOCKDEP) \
lockdep_off(); \
}
static inline void
spl_rw_lockdep_on_maybe(krwlock_t *rwp) \
{ \
if (rwp && rwp->rw_type == RW_NOLOCKDEP) \
lockdep_on(); \
}
#else /* CONFIG_LOCKDEP */
Fix cstyle warnings This patch contains no functional changes. It is solely intended to resolve cstyle warnings in order to facilitate moving the spl source code in to the zfs repository. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #681
2018-02-07 19:49:38 +00:00
#define spl_rw_set_type(rwp, type)
#define spl_rw_lockdep_off_maybe(rwp)
#define spl_rw_lockdep_on_maybe(rwp)
Add new lock types MUTEX_NOLOCKDEP, and RW_NOLOCKDEP When running a kernel with CONFIG_LOCKDEP=y, lockdep reports possible recursive locking in some cases and possible circular locking dependency in others, within the SPL and ZFS modules. When lockdep detects these conditions, it disables further lock analysis for all locks. This causes /proc/lock_stats not to reflect full information about lock contention, even in locks without dependency issues. This commit creates a new type of mutex, MUTEX_NOLOCKDEP. This mutex type causes subsequent attempts to take or release those locks to be wrapped in lockdep_off() and lockdep_on(). This commit also creates an RW_NOLOCKDEP type analagous to MUTEX_NOLOCKDEP. MUTEX_NOLOCKDEP and RW_NOLOCKDEP are also defined in zfs, in a commit to that repo, for userspace builds. Signed-off-by: Olaf Faaland <faaland1@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #480
2015-10-06 21:01:46 +00:00
#endif /* CONFIG_LOCKDEP */
Update rwlocks to track owner to ensure correct semantics The behavior of RW_*_HELD was updated because it was not quite right. It is not sufficient to return non-zero when the lock is help, we must only do this when the current task in the holder. This means we need to track the lock owner which is not something tracked in a Linux semaphore. After some experimentation the solution I settled on was to embed the Linux semaphore at the start of a larger krwlock_t structure which includes the owner field. This maintains good performance and allows us to cleanly intergrate with the kernel lock analysis tools. My reasons: 1) By placing the Linux semaphore at the start of krwlock_t we can then simply cast krwlock_t to a rw_semaphore and pass that on to the linux kernel. This allows us to use '#defines so the preprocessor can do direct replacement of the Solaris primative with the linux equivilant. This is important because it then maintains the location information for each rw_* call point. 2) Additionally, by adding the owner to krwlock_t we can keep this needed extra information adjacent to the lock itself. This removes the need for a fancy lookup to get the owner which is optimal for performance. We can also leverage the existing spin lock in the semaphore to ensure owner is updated correctly. 3) All helper functions which do not need to strictly be implemented as a define to preserve location information can be done as a static inline function. 4) Adding the owner to krwlock_t allows us to remove all memory allocations done during lock initialization. This is good for all the obvious reasons, we do give up the ability to specific the lock name. The Linux profiling tools will stringify the lock name used in the code via the preprocessor and use that. Update rwlocks validated on: - SLES10 (ppc64) - SLES11 (x86_64) - CHAOS4.2 (x86_64) - RHEL5.3 (x86_64) - RHEL6 (x86_64) - FC11 (x86_64)
2009-09-25 21:14:35 +00:00
static inline int
RW_READ_HELD(krwlock_t *rwp)
{
Linux 4.8 compat: Fix RW_READ_HELD Linux 4.8, starting from torvalds/linux@19c5d690e, will set owner to 1 when read held instead of leave it NULL. So we change the condition to `rw_owner(rwp) <= 1` in RW_READ_HELD. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Chunwei Chen <david.chen@osnexus.com> Closes zfsonlinux/zfs#5233 Closes #577
2016-10-08 03:53:58 +00:00
/*
* Linux 4.8 will set owner to 1 when read held instead of leave it
* NULL. So we check whether owner <= 1.
*/
return (spl_rwsem_is_locked(SEM(rwp)) &&
(unsigned long)rw_owner(rwp) <= 1);
Update rwlocks to track owner to ensure correct semantics The behavior of RW_*_HELD was updated because it was not quite right. It is not sufficient to return non-zero when the lock is help, we must only do this when the current task in the holder. This means we need to track the lock owner which is not something tracked in a Linux semaphore. After some experimentation the solution I settled on was to embed the Linux semaphore at the start of a larger krwlock_t structure which includes the owner field. This maintains good performance and allows us to cleanly intergrate with the kernel lock analysis tools. My reasons: 1) By placing the Linux semaphore at the start of krwlock_t we can then simply cast krwlock_t to a rw_semaphore and pass that on to the linux kernel. This allows us to use '#defines so the preprocessor can do direct replacement of the Solaris primative with the linux equivilant. This is important because it then maintains the location information for each rw_* call point. 2) Additionally, by adding the owner to krwlock_t we can keep this needed extra information adjacent to the lock itself. This removes the need for a fancy lookup to get the owner which is optimal for performance. We can also leverage the existing spin lock in the semaphore to ensure owner is updated correctly. 3) All helper functions which do not need to strictly be implemented as a define to preserve location information can be done as a static inline function. 4) Adding the owner to krwlock_t allows us to remove all memory allocations done during lock initialization. This is good for all the obvious reasons, we do give up the ability to specific the lock name. The Linux profiling tools will stringify the lock name used in the code via the preprocessor and use that. Update rwlocks validated on: - SLES10 (ppc64) - SLES11 (x86_64) - CHAOS4.2 (x86_64) - RHEL5.3 (x86_64) - RHEL6 (x86_64) - FC11 (x86_64)
2009-09-25 21:14:35 +00:00
}
static inline int
RW_WRITE_HELD(krwlock_t *rwp)
{
Don't take spin lock on rwlock owner The spin lock around rw_owner is completely unnecessary. The reason is that it is only modified in the down_write context. If you race against another thread modifying it, that means that you aren't holding the rwlock, so taking the spin lock don't eliminate the race. Also, we only check rw_owner in RW_WRITE_HELD because spl_rwsem_is_locked is unnecessary and might need to take spin lock. Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 13:55:06 +00:00
return (rw_owner(rwp) == current);
Update rwlocks to track owner to ensure correct semantics The behavior of RW_*_HELD was updated because it was not quite right. It is not sufficient to return non-zero when the lock is help, we must only do this when the current task in the holder. This means we need to track the lock owner which is not something tracked in a Linux semaphore. After some experimentation the solution I settled on was to embed the Linux semaphore at the start of a larger krwlock_t structure which includes the owner field. This maintains good performance and allows us to cleanly intergrate with the kernel lock analysis tools. My reasons: 1) By placing the Linux semaphore at the start of krwlock_t we can then simply cast krwlock_t to a rw_semaphore and pass that on to the linux kernel. This allows us to use '#defines so the preprocessor can do direct replacement of the Solaris primative with the linux equivilant. This is important because it then maintains the location information for each rw_* call point. 2) Additionally, by adding the owner to krwlock_t we can keep this needed extra information adjacent to the lock itself. This removes the need for a fancy lookup to get the owner which is optimal for performance. We can also leverage the existing spin lock in the semaphore to ensure owner is updated correctly. 3) All helper functions which do not need to strictly be implemented as a define to preserve location information can be done as a static inline function. 4) Adding the owner to krwlock_t allows us to remove all memory allocations done during lock initialization. This is good for all the obvious reasons, we do give up the ability to specific the lock name. The Linux profiling tools will stringify the lock name used in the code via the preprocessor and use that. Update rwlocks validated on: - SLES10 (ppc64) - SLES11 (x86_64) - CHAOS4.2 (x86_64) - RHEL5.3 (x86_64) - RHEL6 (x86_64) - FC11 (x86_64)
2009-09-25 21:14:35 +00:00
}
static inline int
RW_LOCK_HELD(krwlock_t *rwp)
{
Fix cstyle warnings This patch contains no functional changes. It is solely intended to resolve cstyle warnings in order to facilitate moving the spl source code in to the zfs repository. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #681
2018-02-07 19:49:38 +00:00
return (spl_rwsem_is_locked(SEM(rwp)));
Update rwlocks to track owner to ensure correct semantics The behavior of RW_*_HELD was updated because it was not quite right. It is not sufficient to return non-zero when the lock is help, we must only do this when the current task in the holder. This means we need to track the lock owner which is not something tracked in a Linux semaphore. After some experimentation the solution I settled on was to embed the Linux semaphore at the start of a larger krwlock_t structure which includes the owner field. This maintains good performance and allows us to cleanly intergrate with the kernel lock analysis tools. My reasons: 1) By placing the Linux semaphore at the start of krwlock_t we can then simply cast krwlock_t to a rw_semaphore and pass that on to the linux kernel. This allows us to use '#defines so the preprocessor can do direct replacement of the Solaris primative with the linux equivilant. This is important because it then maintains the location information for each rw_* call point. 2) Additionally, by adding the owner to krwlock_t we can keep this needed extra information adjacent to the lock itself. This removes the need for a fancy lookup to get the owner which is optimal for performance. We can also leverage the existing spin lock in the semaphore to ensure owner is updated correctly. 3) All helper functions which do not need to strictly be implemented as a define to preserve location information can be done as a static inline function. 4) Adding the owner to krwlock_t allows us to remove all memory allocations done during lock initialization. This is good for all the obvious reasons, we do give up the ability to specific the lock name. The Linux profiling tools will stringify the lock name used in the code via the preprocessor and use that. Update rwlocks validated on: - SLES10 (ppc64) - SLES11 (x86_64) - CHAOS4.2 (x86_64) - RHEL5.3 (x86_64) - RHEL6 (x86_64) - FC11 (x86_64)
2009-09-25 21:14:35 +00:00
}
/*
Add rwsem_tryupgrade for 4.9.20-rt16 kernel The RT rwsem implementation was changed to allow multiple readers as of the 4.9.20-rt16 patch set. This results in a build failure because the existing implementation was forced to directly access the rwsem structure which has changed. While this could be accommodated by adding additional compatibility code. This patch resolves the build issue by simply assuming the rwsem can never be upgraded. This functionality is a performance optimization and all callers must already handle this case. Converting the last remaining use of __SPIN_LOCK_UNLOCKED to spin_lock_init() was additionally required to get a clean build. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #7589
2018-07-30 16:22:30 +00:00
* The following functions must be a #define and not static inline.
Update rwlocks to track owner to ensure correct semantics The behavior of RW_*_HELD was updated because it was not quite right. It is not sufficient to return non-zero when the lock is help, we must only do this when the current task in the holder. This means we need to track the lock owner which is not something tracked in a Linux semaphore. After some experimentation the solution I settled on was to embed the Linux semaphore at the start of a larger krwlock_t structure which includes the owner field. This maintains good performance and allows us to cleanly intergrate with the kernel lock analysis tools. My reasons: 1) By placing the Linux semaphore at the start of krwlock_t we can then simply cast krwlock_t to a rw_semaphore and pass that on to the linux kernel. This allows us to use '#defines so the preprocessor can do direct replacement of the Solaris primative with the linux equivilant. This is important because it then maintains the location information for each rw_* call point. 2) Additionally, by adding the owner to krwlock_t we can keep this needed extra information adjacent to the lock itself. This removes the need for a fancy lookup to get the owner which is optimal for performance. We can also leverage the existing spin lock in the semaphore to ensure owner is updated correctly. 3) All helper functions which do not need to strictly be implemented as a define to preserve location information can be done as a static inline function. 4) Adding the owner to krwlock_t allows us to remove all memory allocations done during lock initialization. This is good for all the obvious reasons, we do give up the ability to specific the lock name. The Linux profiling tools will stringify the lock name used in the code via the preprocessor and use that. Update rwlocks validated on: - SLES10 (ppc64) - SLES11 (x86_64) - CHAOS4.2 (x86_64) - RHEL5.3 (x86_64) - RHEL6 (x86_64) - FC11 (x86_64)
2009-09-25 21:14:35 +00:00
* This ensures that the native linux semaphore functions (down/up)
* will be correctly located in the users code which is important
* for the built in kernel lock analysis tools
*/
Fix cstyle warnings This patch contains no functional changes. It is solely intended to resolve cstyle warnings in order to facilitate moving the spl source code in to the zfs repository. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #681
2018-02-07 19:49:38 +00:00
/* BEGIN CSTYLED */
#define rw_init(rwp, name, type, arg) \
Use tab indent in rwlock.h Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 16:02:55 +00:00
({ \
static struct lock_class_key __key; \
Add new lock types MUTEX_NOLOCKDEP, and RW_NOLOCKDEP When running a kernel with CONFIG_LOCKDEP=y, lockdep reports possible recursive locking in some cases and possible circular locking dependency in others, within the SPL and ZFS modules. When lockdep detects these conditions, it disables further lock analysis for all locks. This causes /proc/lock_stats not to reflect full information about lock contention, even in locks without dependency issues. This commit creates a new type of mutex, MUTEX_NOLOCKDEP. This mutex type causes subsequent attempts to take or release those locks to be wrapped in lockdep_off() and lockdep_on(). This commit also creates an RW_NOLOCKDEP type analagous to MUTEX_NOLOCKDEP. MUTEX_NOLOCKDEP and RW_NOLOCKDEP are also defined in zfs, in a commit to that repo, for userspace builds. Signed-off-by: Olaf Faaland <faaland1@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #480
2015-10-06 21:01:46 +00:00
ASSERT(type == RW_DEFAULT || type == RW_NOLOCKDEP); \
Use tab indent in rwlock.h Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 16:02:55 +00:00
\
__init_rwsem(SEM(rwp), #rwp, &__key); \
spl_rw_clear_owner(rwp); \
Add new lock types MUTEX_NOLOCKDEP, and RW_NOLOCKDEP When running a kernel with CONFIG_LOCKDEP=y, lockdep reports possible recursive locking in some cases and possible circular locking dependency in others, within the SPL and ZFS modules. When lockdep detects these conditions, it disables further lock analysis for all locks. This causes /proc/lock_stats not to reflect full information about lock contention, even in locks without dependency issues. This commit creates a new type of mutex, MUTEX_NOLOCKDEP. This mutex type causes subsequent attempts to take or release those locks to be wrapped in lockdep_off() and lockdep_on(). This commit also creates an RW_NOLOCKDEP type analagous to MUTEX_NOLOCKDEP. MUTEX_NOLOCKDEP and RW_NOLOCKDEP are also defined in zfs, in a commit to that repo, for userspace builds. Signed-off-by: Olaf Faaland <faaland1@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #480
2015-10-06 21:01:46 +00:00
spl_rw_set_type(rwp, type); \
Reimplement rwlocks for Linux lock profiling/analysis. It turns out that the previous rwlock implementation worked well but did not integrate properly with the upstream kernel lock profiling/ analysis tools. This is a major problem since it would be awfully nice to be able to use the automatic lock checker and profiler. The problem is that the upstream lock tools use the pre-processor to create a lock class for each uniquely named locked. Since the rwsem was embedded in a wrapper structure the name was always the same. The effect was that we only ended up with one lock class for the entire SPL which caused the lock dependency checker to flag nearly everything as a possible deadlock. The solution was to directly map a krwlock to a Linux rwsem using a typedef there by eliminating the wrapper structure. This was not done initially because the rwsem implementation is specific to the arch. To fully implement the Solaris krwlock API using only the provided rwsem API is not possible. It can only be done by directly accessing some of the internal data member of the rwsem structure. For example, the Linux API provides a different function for dropping a reader vs writer lock. Whereas the Solaris API uses the same function and the caller does not pass in what type of lock it is. This means to properly drop the lock we need to determine if the lock is currently a reader or writer lock. Then we need to call the proper Linux API function. Unfortunately, there is no provided API for this so we must extracted this information directly from arch specific lock implementation. This is all do able, and what I did, but it does complicate things considerably. The good news is that in addition to the profiling benefits of this change. We may see performance improvements due to slightly reduced overhead when creating rwlocks and manipulating them. The only function I was forced to sacrafice was rw_owner() because this information is simply not stored anywhere in the rwsem. Luckily this appears not to be a commonly used function on Solaris, and it is my understanding it is mainly used for debugging anyway. In addition to the core rwlock changes, extensive updates were made to the rwlock regression tests. Each class of test was extended to provide more API coverage and to be more rigerous in checking for misbehavior. This is a pretty significant change and with that in mind I have been careful to validate it on several platforms before committing. The full SPLAT regression test suite was run numberous times on all of the following platforms. This includes various kernels ranging from 2.6.16 to 2.6.29. - SLES10 (ppc64) - SLES11 (x86_64) - CHAOS4.2 (x86_64) - RHEL5.3 (x86_64) - RHEL6 (x86_64) - FC11 (x86_64)
2009-09-18 23:09:47 +00:00
})
Initial commit. All spl source written up to this point wrapped in an initial reasonable autoconf style build system. This does not yet build but the configure system does appear to work properly and integrate with the kernel. Hopefully the next commit gets us back to a buildable version we can run the test suite against. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@1 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-02-26 20:36:04 +00:00
Add rwsem_tryupgrade for 4.9.20-rt16 kernel The RT rwsem implementation was changed to allow multiple readers as of the 4.9.20-rt16 patch set. This results in a build failure because the existing implementation was forced to directly access the rwsem structure which has changed. While this could be accommodated by adding additional compatibility code. This patch resolves the build issue by simply assuming the rwsem can never be upgraded. This functionality is a performance optimization and all callers must already handle this case. Converting the last remaining use of __SPIN_LOCK_UNLOCKED to spin_lock_init() was additionally required to get a clean build. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #7589
2018-07-30 16:22:30 +00:00
/*
* The Linux rwsem implementation does not require a matching destroy.
*/
#define rw_destroy(rwp) ((void) 0)
Add some missing rw_lock symbols git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@27 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-03-06 23:42:37 +00:00
Fix cstyle warnings This patch contains no functional changes. It is solely intended to resolve cstyle warnings in order to facilitate moving the spl source code in to the zfs repository. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #681
2018-02-07 19:49:38 +00:00
#define rw_tryenter(rwp, rw) \
Use tab indent in rwlock.h Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 16:02:55 +00:00
({ \
int _rc_ = 0; \
\
Add new lock types MUTEX_NOLOCKDEP, and RW_NOLOCKDEP When running a kernel with CONFIG_LOCKDEP=y, lockdep reports possible recursive locking in some cases and possible circular locking dependency in others, within the SPL and ZFS modules. When lockdep detects these conditions, it disables further lock analysis for all locks. This causes /proc/lock_stats not to reflect full information about lock contention, even in locks without dependency issues. This commit creates a new type of mutex, MUTEX_NOLOCKDEP. This mutex type causes subsequent attempts to take or release those locks to be wrapped in lockdep_off() and lockdep_on(). This commit also creates an RW_NOLOCKDEP type analagous to MUTEX_NOLOCKDEP. MUTEX_NOLOCKDEP and RW_NOLOCKDEP are also defined in zfs, in a commit to that repo, for userspace builds. Signed-off-by: Olaf Faaland <faaland1@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #480
2015-10-06 21:01:46 +00:00
spl_rw_lockdep_off_maybe(rwp); \
Use tab indent in rwlock.h Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 16:02:55 +00:00
switch (rw) { \
case RW_READER: \
_rc_ = down_read_trylock(SEM(rwp)); \
break; \
case RW_WRITER: \
if ((_rc_ = down_write_trylock(SEM(rwp)))) \
spl_rw_set_owner(rwp); \
break; \
default: \
VERIFY(0); \
} \
Add new lock types MUTEX_NOLOCKDEP, and RW_NOLOCKDEP When running a kernel with CONFIG_LOCKDEP=y, lockdep reports possible recursive locking in some cases and possible circular locking dependency in others, within the SPL and ZFS modules. When lockdep detects these conditions, it disables further lock analysis for all locks. This causes /proc/lock_stats not to reflect full information about lock contention, even in locks without dependency issues. This commit creates a new type of mutex, MUTEX_NOLOCKDEP. This mutex type causes subsequent attempts to take or release those locks to be wrapped in lockdep_off() and lockdep_on(). This commit also creates an RW_NOLOCKDEP type analagous to MUTEX_NOLOCKDEP. MUTEX_NOLOCKDEP and RW_NOLOCKDEP are also defined in zfs, in a commit to that repo, for userspace builds. Signed-off-by: Olaf Faaland <faaland1@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #480
2015-10-06 21:01:46 +00:00
spl_rw_lockdep_on_maybe(rwp); \
Use tab indent in rwlock.h Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 16:02:55 +00:00
_rc_; \
- Updated rwlock's to reside in a .c file instead of a static inline - Updated rwlock's so they can be safely initialized in ctors. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@96 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-05-06 23:00:49 +00:00
})
Fix cstyle warnings This patch contains no functional changes. It is solely intended to resolve cstyle warnings in order to facilitate moving the spl source code in to the zfs repository. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #681
2018-02-07 19:49:38 +00:00
#define rw_enter(rwp, rw) \
Use tab indent in rwlock.h Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 16:02:55 +00:00
({ \
Add new lock types MUTEX_NOLOCKDEP, and RW_NOLOCKDEP When running a kernel with CONFIG_LOCKDEP=y, lockdep reports possible recursive locking in some cases and possible circular locking dependency in others, within the SPL and ZFS modules. When lockdep detects these conditions, it disables further lock analysis for all locks. This causes /proc/lock_stats not to reflect full information about lock contention, even in locks without dependency issues. This commit creates a new type of mutex, MUTEX_NOLOCKDEP. This mutex type causes subsequent attempts to take or release those locks to be wrapped in lockdep_off() and lockdep_on(). This commit also creates an RW_NOLOCKDEP type analagous to MUTEX_NOLOCKDEP. MUTEX_NOLOCKDEP and RW_NOLOCKDEP are also defined in zfs, in a commit to that repo, for userspace builds. Signed-off-by: Olaf Faaland <faaland1@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #480
2015-10-06 21:01:46 +00:00
spl_rw_lockdep_off_maybe(rwp); \
Use tab indent in rwlock.h Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 16:02:55 +00:00
switch (rw) { \
case RW_READER: \
down_read(SEM(rwp)); \
break; \
case RW_WRITER: \
down_write(SEM(rwp)); \
spl_rw_set_owner(rwp); \
break; \
default: \
VERIFY(0); \
} \
Add new lock types MUTEX_NOLOCKDEP, and RW_NOLOCKDEP When running a kernel with CONFIG_LOCKDEP=y, lockdep reports possible recursive locking in some cases and possible circular locking dependency in others, within the SPL and ZFS modules. When lockdep detects these conditions, it disables further lock analysis for all locks. This causes /proc/lock_stats not to reflect full information about lock contention, even in locks without dependency issues. This commit creates a new type of mutex, MUTEX_NOLOCKDEP. This mutex type causes subsequent attempts to take or release those locks to be wrapped in lockdep_off() and lockdep_on(). This commit also creates an RW_NOLOCKDEP type analagous to MUTEX_NOLOCKDEP. MUTEX_NOLOCKDEP and RW_NOLOCKDEP are also defined in zfs, in a commit to that repo, for userspace builds. Signed-off-by: Olaf Faaland <faaland1@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #480
2015-10-06 21:01:46 +00:00
spl_rw_lockdep_on_maybe(rwp); \
Reimplement rwlocks for Linux lock profiling/analysis. It turns out that the previous rwlock implementation worked well but did not integrate properly with the upstream kernel lock profiling/ analysis tools. This is a major problem since it would be awfully nice to be able to use the automatic lock checker and profiler. The problem is that the upstream lock tools use the pre-processor to create a lock class for each uniquely named locked. Since the rwsem was embedded in a wrapper structure the name was always the same. The effect was that we only ended up with one lock class for the entire SPL which caused the lock dependency checker to flag nearly everything as a possible deadlock. The solution was to directly map a krwlock to a Linux rwsem using a typedef there by eliminating the wrapper structure. This was not done initially because the rwsem implementation is specific to the arch. To fully implement the Solaris krwlock API using only the provided rwsem API is not possible. It can only be done by directly accessing some of the internal data member of the rwsem structure. For example, the Linux API provides a different function for dropping a reader vs writer lock. Whereas the Solaris API uses the same function and the caller does not pass in what type of lock it is. This means to properly drop the lock we need to determine if the lock is currently a reader or writer lock. Then we need to call the proper Linux API function. Unfortunately, there is no provided API for this so we must extracted this information directly from arch specific lock implementation. This is all do able, and what I did, but it does complicate things considerably. The good news is that in addition to the profiling benefits of this change. We may see performance improvements due to slightly reduced overhead when creating rwlocks and manipulating them. The only function I was forced to sacrafice was rw_owner() because this information is simply not stored anywhere in the rwsem. Luckily this appears not to be a commonly used function on Solaris, and it is my understanding it is mainly used for debugging anyway. In addition to the core rwlock changes, extensive updates were made to the rwlock regression tests. Each class of test was extended to provide more API coverage and to be more rigerous in checking for misbehavior. This is a pretty significant change and with that in mind I have been careful to validate it on several platforms before committing. The full SPLAT regression test suite was run numberous times on all of the following platforms. This includes various kernels ranging from 2.6.16 to 2.6.29. - SLES10 (ppc64) - SLES11 (x86_64) - CHAOS4.2 (x86_64) - RHEL5.3 (x86_64) - RHEL6 (x86_64) - FC11 (x86_64)
2009-09-18 23:09:47 +00:00
})
Initial commit. All spl source written up to this point wrapped in an initial reasonable autoconf style build system. This does not yet build but the configure system does appear to work properly and integrate with the kernel. Hopefully the next commit gets us back to a buildable version we can run the test suite against. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@1 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-02-26 20:36:04 +00:00
Fix cstyle warnings This patch contains no functional changes. It is solely intended to resolve cstyle warnings in order to facilitate moving the spl source code in to the zfs repository. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #681
2018-02-07 19:49:38 +00:00
#define rw_exit(rwp) \
Use tab indent in rwlock.h Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 16:02:55 +00:00
({ \
Add new lock types MUTEX_NOLOCKDEP, and RW_NOLOCKDEP When running a kernel with CONFIG_LOCKDEP=y, lockdep reports possible recursive locking in some cases and possible circular locking dependency in others, within the SPL and ZFS modules. When lockdep detects these conditions, it disables further lock analysis for all locks. This causes /proc/lock_stats not to reflect full information about lock contention, even in locks without dependency issues. This commit creates a new type of mutex, MUTEX_NOLOCKDEP. This mutex type causes subsequent attempts to take or release those locks to be wrapped in lockdep_off() and lockdep_on(). This commit also creates an RW_NOLOCKDEP type analagous to MUTEX_NOLOCKDEP. MUTEX_NOLOCKDEP and RW_NOLOCKDEP are also defined in zfs, in a commit to that repo, for userspace builds. Signed-off-by: Olaf Faaland <faaland1@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #480
2015-10-06 21:01:46 +00:00
spl_rw_lockdep_off_maybe(rwp); \
Use tab indent in rwlock.h Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 16:02:55 +00:00
if (RW_WRITE_HELD(rwp)) { \
spl_rw_clear_owner(rwp); \
up_write(SEM(rwp)); \
} else { \
ASSERT(RW_READ_HELD(rwp)); \
up_read(SEM(rwp)); \
} \
Add new lock types MUTEX_NOLOCKDEP, and RW_NOLOCKDEP When running a kernel with CONFIG_LOCKDEP=y, lockdep reports possible recursive locking in some cases and possible circular locking dependency in others, within the SPL and ZFS modules. When lockdep detects these conditions, it disables further lock analysis for all locks. This causes /proc/lock_stats not to reflect full information about lock contention, even in locks without dependency issues. This commit creates a new type of mutex, MUTEX_NOLOCKDEP. This mutex type causes subsequent attempts to take or release those locks to be wrapped in lockdep_off() and lockdep_on(). This commit also creates an RW_NOLOCKDEP type analagous to MUTEX_NOLOCKDEP. MUTEX_NOLOCKDEP and RW_NOLOCKDEP are also defined in zfs, in a commit to that repo, for userspace builds. Signed-off-by: Olaf Faaland <faaland1@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #480
2015-10-06 21:01:46 +00:00
spl_rw_lockdep_on_maybe(rwp); \
Update rwlocks to track owner to ensure correct semantics The behavior of RW_*_HELD was updated because it was not quite right. It is not sufficient to return non-zero when the lock is help, we must only do this when the current task in the holder. This means we need to track the lock owner which is not something tracked in a Linux semaphore. After some experimentation the solution I settled on was to embed the Linux semaphore at the start of a larger krwlock_t structure which includes the owner field. This maintains good performance and allows us to cleanly intergrate with the kernel lock analysis tools. My reasons: 1) By placing the Linux semaphore at the start of krwlock_t we can then simply cast krwlock_t to a rw_semaphore and pass that on to the linux kernel. This allows us to use '#defines so the preprocessor can do direct replacement of the Solaris primative with the linux equivilant. This is important because it then maintains the location information for each rw_* call point. 2) Additionally, by adding the owner to krwlock_t we can keep this needed extra information adjacent to the lock itself. This removes the need for a fancy lookup to get the owner which is optimal for performance. We can also leverage the existing spin lock in the semaphore to ensure owner is updated correctly. 3) All helper functions which do not need to strictly be implemented as a define to preserve location information can be done as a static inline function. 4) Adding the owner to krwlock_t allows us to remove all memory allocations done during lock initialization. This is good for all the obvious reasons, we do give up the ability to specific the lock name. The Linux profiling tools will stringify the lock name used in the code via the preprocessor and use that. Update rwlocks validated on: - SLES10 (ppc64) - SLES11 (x86_64) - CHAOS4.2 (x86_64) - RHEL5.3 (x86_64) - RHEL6 (x86_64) - FC11 (x86_64)
2009-09-25 21:14:35 +00:00
})
Fix cstyle warnings This patch contains no functional changes. It is solely intended to resolve cstyle warnings in order to facilitate moving the spl source code in to the zfs repository. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #681
2018-02-07 19:49:38 +00:00
#define rw_downgrade(rwp) \
Use tab indent in rwlock.h Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 16:02:55 +00:00
({ \
Add new lock types MUTEX_NOLOCKDEP, and RW_NOLOCKDEP When running a kernel with CONFIG_LOCKDEP=y, lockdep reports possible recursive locking in some cases and possible circular locking dependency in others, within the SPL and ZFS modules. When lockdep detects these conditions, it disables further lock analysis for all locks. This causes /proc/lock_stats not to reflect full information about lock contention, even in locks without dependency issues. This commit creates a new type of mutex, MUTEX_NOLOCKDEP. This mutex type causes subsequent attempts to take or release those locks to be wrapped in lockdep_off() and lockdep_on(). This commit also creates an RW_NOLOCKDEP type analagous to MUTEX_NOLOCKDEP. MUTEX_NOLOCKDEP and RW_NOLOCKDEP are also defined in zfs, in a commit to that repo, for userspace builds. Signed-off-by: Olaf Faaland <faaland1@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #480
2015-10-06 21:01:46 +00:00
spl_rw_lockdep_off_maybe(rwp); \
Use tab indent in rwlock.h Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 16:02:55 +00:00
spl_rw_clear_owner(rwp); \
downgrade_write(SEM(rwp)); \
Add new lock types MUTEX_NOLOCKDEP, and RW_NOLOCKDEP When running a kernel with CONFIG_LOCKDEP=y, lockdep reports possible recursive locking in some cases and possible circular locking dependency in others, within the SPL and ZFS modules. When lockdep detects these conditions, it disables further lock analysis for all locks. This causes /proc/lock_stats not to reflect full information about lock contention, even in locks without dependency issues. This commit creates a new type of mutex, MUTEX_NOLOCKDEP. This mutex type causes subsequent attempts to take or release those locks to be wrapped in lockdep_off() and lockdep_on(). This commit also creates an RW_NOLOCKDEP type analagous to MUTEX_NOLOCKDEP. MUTEX_NOLOCKDEP and RW_NOLOCKDEP are also defined in zfs, in a commit to that repo, for userspace builds. Signed-off-by: Olaf Faaland <faaland1@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #480
2015-10-06 21:01:46 +00:00
spl_rw_lockdep_on_maybe(rwp); \
Update rwlocks to track owner to ensure correct semantics The behavior of RW_*_HELD was updated because it was not quite right. It is not sufficient to return non-zero when the lock is help, we must only do this when the current task in the holder. This means we need to track the lock owner which is not something tracked in a Linux semaphore. After some experimentation the solution I settled on was to embed the Linux semaphore at the start of a larger krwlock_t structure which includes the owner field. This maintains good performance and allows us to cleanly intergrate with the kernel lock analysis tools. My reasons: 1) By placing the Linux semaphore at the start of krwlock_t we can then simply cast krwlock_t to a rw_semaphore and pass that on to the linux kernel. This allows us to use '#defines so the preprocessor can do direct replacement of the Solaris primative with the linux equivilant. This is important because it then maintains the location information for each rw_* call point. 2) Additionally, by adding the owner to krwlock_t we can keep this needed extra information adjacent to the lock itself. This removes the need for a fancy lookup to get the owner which is optimal for performance. We can also leverage the existing spin lock in the semaphore to ensure owner is updated correctly. 3) All helper functions which do not need to strictly be implemented as a define to preserve location information can be done as a static inline function. 4) Adding the owner to krwlock_t allows us to remove all memory allocations done during lock initialization. This is good for all the obvious reasons, we do give up the ability to specific the lock name. The Linux profiling tools will stringify the lock name used in the code via the preprocessor and use that. Update rwlocks validated on: - SLES10 (ppc64) - SLES11 (x86_64) - CHAOS4.2 (x86_64) - RHEL5.3 (x86_64) - RHEL6 (x86_64) - FC11 (x86_64)
2009-09-25 21:14:35 +00:00
})
Fix cstyle warnings This patch contains no functional changes. It is solely intended to resolve cstyle warnings in order to facilitate moving the spl source code in to the zfs repository. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #681
2018-02-07 19:49:38 +00:00
#define rw_tryupgrade(rwp) \
Use tab indent in rwlock.h Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 16:02:55 +00:00
({ \
int _rc_ = 0; \
\
Add rw_tryupgrade() This implementation of rw_tryupgrade() behaves slightly differently from its counterparts on other platforms. It drops the RW_READER lock and then acquires the RW_WRITER lock leaving a small window where no lock is held. On other platforms the lock is never released during the upgrade process. This is necessary under Linux because the kernel does not provide an upgrade function. There are currently no callers in the ZFS code where this change in behavior is a problem. In fact, in most cases the code is already written such that if the upgrade fails the RW_READER lock is dropped and the caller blocks waiting to acquire the lock as RW_WRITER. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Tim Chase <tim@chase2k.com> Signed-off-by: Matthew Thode <prometheanfire@gentoo.org> Closes zfsonlinux/zfs#4388 Closes #534
2016-03-09 22:20:48 +00:00
if (RW_WRITE_HELD(rwp)) { \
_rc_ = 1; \
} else { \
Implement a proper rw_tryupgrade Current rw_tryupgrade does rw_exit and then rw_tryenter(RW_RWITER), and then does rw_enter(RW_READER) if it fails. This violate the assumption that rw_tryupgrade should be atomic and could cause extra contention or even lock inversion. This patch we implement a proper rw_tryupgrade. For rwsem-spinlock, we take the spinlock to check rwsem->count and rwsem->wait_list. For normal rwsem, we use cmpxchg on rwsem->count to change the value from single reader to single writer. Signed-off-by: Chunwei Chen <david.chen@osnexus.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Tim Chase <tim@chase2k.com> Closes zfsonlinux/zfs#4692 Closes #554
2016-05-25 23:35:42 +00:00
spl_rw_lockdep_off_maybe(rwp); \
if ((_rc_ = rwsem_tryupgrade(SEM(rwp)))) \
spl_rw_set_owner(rwp); \
spl_rw_lockdep_on_maybe(rwp); \
Use tab indent in rwlock.h Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #473
2015-09-01 16:02:55 +00:00
} \
_rc_; \
Update rwlocks to track owner to ensure correct semantics The behavior of RW_*_HELD was updated because it was not quite right. It is not sufficient to return non-zero when the lock is help, we must only do this when the current task in the holder. This means we need to track the lock owner which is not something tracked in a Linux semaphore. After some experimentation the solution I settled on was to embed the Linux semaphore at the start of a larger krwlock_t structure which includes the owner field. This maintains good performance and allows us to cleanly intergrate with the kernel lock analysis tools. My reasons: 1) By placing the Linux semaphore at the start of krwlock_t we can then simply cast krwlock_t to a rw_semaphore and pass that on to the linux kernel. This allows us to use '#defines so the preprocessor can do direct replacement of the Solaris primative with the linux equivilant. This is important because it then maintains the location information for each rw_* call point. 2) Additionally, by adding the owner to krwlock_t we can keep this needed extra information adjacent to the lock itself. This removes the need for a fancy lookup to get the owner which is optimal for performance. We can also leverage the existing spin lock in the semaphore to ensure owner is updated correctly. 3) All helper functions which do not need to strictly be implemented as a define to preserve location information can be done as a static inline function. 4) Adding the owner to krwlock_t allows us to remove all memory allocations done during lock initialization. This is good for all the obvious reasons, we do give up the ability to specific the lock name. The Linux profiling tools will stringify the lock name used in the code via the preprocessor and use that. Update rwlocks validated on: - SLES10 (ppc64) - SLES11 (x86_64) - CHAOS4.2 (x86_64) - RHEL5.3 (x86_64) - RHEL6 (x86_64) - FC11 (x86_64)
2009-09-25 21:14:35 +00:00
})
Fix cstyle warnings This patch contains no functional changes. It is solely intended to resolve cstyle warnings in order to facilitate moving the spl source code in to the zfs repository. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #681
2018-02-07 19:49:38 +00:00
/* END CSTYLED */
Update rwlocks to track owner to ensure correct semantics The behavior of RW_*_HELD was updated because it was not quite right. It is not sufficient to return non-zero when the lock is help, we must only do this when the current task in the holder. This means we need to track the lock owner which is not something tracked in a Linux semaphore. After some experimentation the solution I settled on was to embed the Linux semaphore at the start of a larger krwlock_t structure which includes the owner field. This maintains good performance and allows us to cleanly intergrate with the kernel lock analysis tools. My reasons: 1) By placing the Linux semaphore at the start of krwlock_t we can then simply cast krwlock_t to a rw_semaphore and pass that on to the linux kernel. This allows us to use '#defines so the preprocessor can do direct replacement of the Solaris primative with the linux equivilant. This is important because it then maintains the location information for each rw_* call point. 2) Additionally, by adding the owner to krwlock_t we can keep this needed extra information adjacent to the lock itself. This removes the need for a fancy lookup to get the owner which is optimal for performance. We can also leverage the existing spin lock in the semaphore to ensure owner is updated correctly. 3) All helper functions which do not need to strictly be implemented as a define to preserve location information can be done as a static inline function. 4) Adding the owner to krwlock_t allows us to remove all memory allocations done during lock initialization. This is good for all the obvious reasons, we do give up the ability to specific the lock name. The Linux profiling tools will stringify the lock name used in the code via the preprocessor and use that. Update rwlocks validated on: - SLES10 (ppc64) - SLES11 (x86_64) - CHAOS4.2 (x86_64) - RHEL5.3 (x86_64) - RHEL6 (x86_64) - FC11 (x86_64)
2009-09-25 21:14:35 +00:00
int spl_rw_init(void);
void spl_rw_fini(void);
Prepare SPL repo to merge with ZFS repo This commit removes everything from the repository except the core SPL implementation for Linux. Those files which remain have been moved to non-conflicting locations to facilitate the merge. The README.md and associated files have been updated accordingly. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2018-02-15 01:01:15 +00:00
int rwsem_tryupgrade(struct rw_semaphore *rwsem);
Update rwlocks to track owner to ensure correct semantics The behavior of RW_*_HELD was updated because it was not quite right. It is not sufficient to return non-zero when the lock is help, we must only do this when the current task in the holder. This means we need to track the lock owner which is not something tracked in a Linux semaphore. After some experimentation the solution I settled on was to embed the Linux semaphore at the start of a larger krwlock_t structure which includes the owner field. This maintains good performance and allows us to cleanly intergrate with the kernel lock analysis tools. My reasons: 1) By placing the Linux semaphore at the start of krwlock_t we can then simply cast krwlock_t to a rw_semaphore and pass that on to the linux kernel. This allows us to use '#defines so the preprocessor can do direct replacement of the Solaris primative with the linux equivilant. This is important because it then maintains the location information for each rw_* call point. 2) Additionally, by adding the owner to krwlock_t we can keep this needed extra information adjacent to the lock itself. This removes the need for a fancy lookup to get the owner which is optimal for performance. We can also leverage the existing spin lock in the semaphore to ensure owner is updated correctly. 3) All helper functions which do not need to strictly be implemented as a define to preserve location information can be done as a static inline function. 4) Adding the owner to krwlock_t allows us to remove all memory allocations done during lock initialization. This is good for all the obvious reasons, we do give up the ability to specific the lock name. The Linux profiling tools will stringify the lock name used in the code via the preprocessor and use that. Update rwlocks validated on: - SLES10 (ppc64) - SLES11 (x86_64) - CHAOS4.2 (x86_64) - RHEL5.3 (x86_64) - RHEL6 (x86_64) - FC11 (x86_64)
2009-09-25 21:14:35 +00:00
- Updated rwlock's to reside in a .c file instead of a static inline - Updated rwlock's so they can be safely initialized in ctors. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@96 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-05-06 23:00:49 +00:00
#endif /* _SPL_RWLOCK_H */