Commit Graph

351 Commits

Author SHA1 Message Date
Chunwei Chen 1538f4b6e3 Linux 3.15 compat: NICE_TO_PRIO and PRIO_TO_NICE
These macro's were exposed to make them available to other
parts of the kernel and modules.

References:
  torvalds/linux@6b6350f

Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #355
2014-05-07 13:38:03 -07:00
Jorgen Lundman d6e6e4a98e Add support for aarch64 (ARMv8)
Using the ARM reference simulation (fast model foundation v8) I
cross compiled spl and zfs, to confirm it works on ARMv8 (64 bit
arm architecture, called aarch64 in Linux).

As it is based on previous ARM porting, the resulting patch is
disappointingly small, there was very little to do. The code fixes
the compile issues and has light testing done.

Signed-off-by: Jorgen Lundman <lundman@lundman.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #351
2014-04-25 15:25:32 -07:00
Chunwei Chen 545e9ac00a Add ddi_time_after and friends
When comparing times gotten from ddi_get_lbolt, we have to take account of
wrap around of jiffies. Therefore, we cannot use 't1 < t2'. Instead we should
use 't1 - t2 < 0'.

This patch add ddi_time_after and friends to address this issue. They have
strict type restriction, clock_t for vanilla and int64_t for 64 version, to
prevent type conversion from screwing things.

Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #335
2014-04-14 09:32:01 -07:00
Yuxuan Shui 6c48cd8ac2 This patch add a CTASSERT macro for compile time assertion.
This macro makes the compile to spit "mixed definition and code"
warning, I can't find a way to avoid it.

This patch lays some groundwork for the persistent l2arc feature.
See https://www.illumos.org/issues/3525.

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #303
2014-04-14 09:28:53 -07:00
Richard Yao acf0ade362 Simplify hostid logic
There is plenty of compatibility code for a hw_hostid
that isn't used by anything. At the same time, there are apparently
issues with the current hostid logic. coredumb in #zfsonlinux on
freenode reported that Fedora 17 changes its hostid on every boot, which
required force importing his pool. A suggestion by wca was to adopt
FreeBSD's behavior, where it treats hostid as zero if /etc/hostid does
not exist

Adopting FreeBSD's behavior permits us to eliminate plenty of code,
including a userland helper that invokes the system's hostid as a
fallback.

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #224
2014-04-14 09:04:41 -07:00
Tim Chase ed650dee76 De-inline spl_kthread_create().
The function was defined as a static inline with variable arguments
which causes gcc to generate errors on some distros.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes #346
2014-04-09 19:17:12 -07:00
Tim Chase 17a527cb0f Support post-3.13 kthread_create() semantics.
Provide spl_kthread_create() as a wrapper to the kernel's kthread_create()
to provide pre-3.13 semantics.  Re-try if the call is interrupted or if it
would have returned -ENOMEM.  Otherwise return NULL.

Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #339
2014-04-08 12:44:42 -07:00
marku89 d58a99af2f Define the needed ISA types for Sparc
Add the minimum required ISA types to support the Sparc
architecture.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: marku89 <mar42@kola.li>
Closes #317
2014-01-09 15:55:32 -08:00
Brian Behlendorf 2f117de8be Include linux/vmalloc.h for ARM and Sparc
Related to issue #257 which added Linux 3.10 compatibility.  For
ARM and Sparc architectures we must explicitly include the
<linux/vmalloc.h> header to ensure the vmalloc_info structure
is always defined when available.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #257
Closes #291
2014-01-07 10:45:39 -08:00
Ned Bass 184c687387 Emulate illumos interface cv_timedwait_hires()
Needed for Illumos #3582. This interface is supposed to support
a variable-resolution timeout with nanosecond granularity.  This
implementation rounds up to microsecond resolution, as nanosecond-
precision timing is rarely needed for real-world performance
tuning and may incur unnecessary busy-waiting.  usleep_range() is
used if available, otherwise udelay() or msleep() are used
depending on the length of the delay interval.

Add flags from sys/callo.h as these are used to control the behavior of
cv_timedwait_hires().  Specifically,

CALLOUT_FLAG_ABSOLUTE
    Normally, the expiration passed to the timeout API functions is
    an expiration interval. If this flag is specified, then it is
    interpreted as the expiration time itself.

CALLOUT_FLAG_ROUNDUP
    Roundup the expiration time to the next resolution boundary. If this
    flag is not specified, the expiration time is rounded down.

References:
    https://www.illumos.org/issues/3582
    illumos/illumos-gate@0689f76

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #304
2013-11-04 09:49:24 -08:00
Ned Bass f483a97a41 3537 add kstat_waitq_enter and friends
These kstat interfaces are required to port
"Illumos #3537 want pool io kstats" to ZFS on Linux.

kstat_waitq_enter()
kstat_waitq_exit()
kstat_runq_enter()
kstat_runq_exit()

Additionally, zero out the ks_data buffer in __kstat_create() so
that the kstat_io_t counters are initialized to zero.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-10-25 13:41:52 -07:00
Cyril Plisko ffbf0e57c2 Kstat to use private lock by default
While porting Illumos #3537 I found that ks_lock member of kstat_t
structure is different between Illumos and SPL. It is a pointer to
the kmutex_t in Illumos, but the mutex lock itself in SPL.
Apparently Illumos kstat API allows consumer to override the lock
if required. With SPL implementation it is not possible anymore.

Things were alright until the first attempt to actually override
the lock. Porting of Illumos #3537 introduced such code for the
first time.

In order to provide the Solaris/Illumos like functionality we:
  1. convert ks_lock to "kmutex_t *ks_lock"
  2. create a new field "kmutex_t ks_private_lock"
  3. On kstat_create() ks_lock = &ks_private_lock

Thus if consumer doesn't care we still have our internal lock in use.
If, however, consumer does care she has a chance to set ks_lock to
anything else before calling kstat_install().

The rest of the code will use ks_lock regardless of its origin.

Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #286
2013-10-25 13:41:30 -07:00
Brian Behlendorf ce07767f79 Revert "Add KSTAT_TYPE_TXG type"
This reverts commit dba79fcbf2 in
favor of using the generic KSTAT_TYPE_RAW callbacks.  The advantage
of this approach is that arbitrary types can be added without the
need to add them to the SPL.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #296
2013-10-16 14:48:35 -07:00
Prakash Surya 09f38b7e60 Add wrappers for accessing PID and command info
This change adds simple wrappers for accessing a thread's PID and
command character string.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #296
2013-10-16 14:48:35 -07:00
Prakash Surya 56d40a686b Add callbacks for displaying KSTAT_TYPE_RAW kstats
The current implementation for displaying kstats of type KSTAT_TYPE_RAW
is rather crude. This patch attempts to enhance this handling by
allowing a kstat user to register formatting callbacks which can
optionally be used.

The callbacks allow the user to implement functions for interpreting
their data and transposing it into a character buffer. This buffer,
containing a string representation of the raw data, is then be displayed
through the current /proc textual interface.

Additionally the kstats are made writable because it's now possible
to provide a useful handler via the existing ks_update() interface.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #296
2013-10-16 14:48:35 -07:00
Richard Yao 4768c0d0a6 Define SET_ERROR()
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-10-09 14:20:46 -07:00
Ned Bass 3ecf2d2bb6 Add kpreempt() compatibility macro
This is needed for the Illumos #4045 write throttle patch.  It is used
in the arc eviction code to avoid blocking all arc activity by sitting on
arcs_mtx too long.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #286
2013-10-09 13:52:55 -07:00
Richard Yao f7fd6ddd96 Linux 3.8 compat: Use kuid_t/kgid_t when required
When CONFIG_UIDGID_STRICT_TYPE_CHECKS is enabled uid_t/git_t are
replaced by kuid_t/kgid_t, which are structures instead of integral
types. This causes any code that uses an integral type to fail to build.
The User Namespace functionality introduced in Linux 3.8 requires
CONFIG_UIDGID_STRICT_TYPE_CHECKS, so we could not build against any
kernel that supported it.

We resolve this by converting between the new kuid_t/kgid_t structures
and the original uid_t/gid_t types.

Original-patch-by: DHE
Rewrite-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #260
2013-08-09 10:09:29 -07:00
Richard Yao ba06298072 Linux 3.11 compat: Replace num_physpages with totalram_pages
num_physpages was removed by
torvalds/linux@cfa11e08ed, so lets replace
it with totalram_pages.

This is a bug fix as much as it is a compatibility fix because
num_physpages did not reflect the number of pages actually available to
the kernel:

http://lkml.indiana.edu/hypermail/linux/kernel/0908.2/01001.html

Also, there are known issues with memory calculations when ZFS is in a
Xen dom0. There is a chance that using totalram_pages could resolve
them. This conjecture is untested at the time of writing.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #273
2013-08-08 09:14:29 -07:00
Richard Yao f2a745c41d Linux 3.10 compat: Do not rely on struct proc_dir_entry definition
Linux kernel commit torvalds/linux#59d8053f moved the definition of
struct proc_dir_entry from include/linux/proc_fs.h to the private
header fs/proc/internal.h. The SPL relied on that to map Solaris'
kstat to entries in /proc/spl/kstat.

Since the proc_dir_entry structure is now private the only safe
thing to do is wrap the opaque proc handle with our own structure.
This actually ends up simplify the code and is good because it
moves us away from depending on implementation details of /proc.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #257
2013-07-08 15:25:18 -07:00
Yuxuan Shui c02ab72fb9 Linux 3.10 compat: struct vmalloc_info moved
Linux kernel commmit torvalds/linux@db3808c1 moved the
vmalloc_info structure from a private to a public header.
Now that it's available for kernel modules use it.

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #257
2013-07-08 15:09:20 -07:00
Brian Behlendorf ab0fdfef52 Fix ASSERT0 and VERIFY0 macro typo
Ensure the value is cast to a 'long long' for printing purposes.  The
expectation is that ASSERT0/VERIFY0 are mostly used for validating
return values and thus may commonly be negative.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #246
2013-06-21 15:38:46 -07:00
Brian Behlendorf 1c6d149feb Add ASSERT0 and VERIFY0 macros
The Illumos code introduced the ASSERT0 and VERIFY0 macros which
are to be used instead of ASSERT3S(x, ==, 0) and VERIFY3S(x, ==, 0).

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Madhav Suresh <madhav.suresh@delphix.com>
Closes #246
2013-06-18 11:41:55 -07:00
Brian Behlendorf ab59be7bc7 Fix delay()
Somewhat amazingly it went unnoticed that the delay() function
doesn't actually cause the task to block.  Since the task state
is never changed from TASK_RUNNING before schedule_timeout() the
scheduler allows to task to continue running without any delay.
Using schedule_timeout_interruptible() resolves the issue by
correctly setting TASK_UNINTERRUPTIBLE.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-05-01 16:35:47 -07:00
Brian Behlendorf f6437b60c2 Add msec/usec/nsec to tick convertors
Add wrappers for the Solaris MSEC_TO_TICK, USEC_TO_TICK, and
NSEC_TO_TICK conversion functions.  They are mapped directly to
their Linux counterparts with the exception of NSEC_TO_TICK
can cannot use usecs_to_jiffies() because it is not exported
by the kernel.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-05-01 12:07:56 -07:00
Brian Behlendorf 4a6d8d2c3e Change spl-kmod-devel install path
Install the common spl kernel development headers under
/usr/src/spl-<version>/ rather than in a kernel specific
directory.  The kernel specific build products such as
spl_config.h and Modules.symvers are left installed under
/usr/src/spl-<version>/<kernel>.

This was done to be consistent with where dkms expects
kernel module source to be packaged.  It also allows for
a common spl-kmod-devel package which includes the headers,
and per-kernel spl-kmod-devel-<kernel> packages.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-14 12:01:05 -07:00
Richard Yao 10087fe1fa Linux 3.9 compat: Include linux/sched/rt.h
Linux 3.9 reorganized sched.h, splitting it into numerous files.
torvalds/linux@8bd75c77b7 moved MAX_PRIO
and MAX_RT_PRIO to linux/sched/rt.h.

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-14 10:43:19 -07:00
Ned Bass 3d6af2dd6d 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>
2013-03-04 19:09:34 -08:00
Brian Behlendorf d1142fbffe Remove custom install-data-local for headers
Rather than use a custom install target it is cleaner to define
a 'kerneldir' and set 'kernel_HEADERS' appropriately.  This
allows us to leverage the standing configure install support.

Additionally, I took this opertunity add the missing make files
to the include subdirectories.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-01 16:55:06 -08:00
Eric Dillmann 3cbfd259b7 Define BE_IN16 & BE_IN32 for lz4 compression
The new lz4 compression algorithm, zfsonlinux/zfs@9759c60, requires
the generic BE_IN16 and BE_IN32 functions.  These are added to the SPL
for other consumers to take advantage of.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-01-29 09:30:23 -08:00
Brian Behlendorf 0936c3449f Add spl_kmem_cache_expire module option
Cache aging was implemented because it was part of the default Solaris
kmem_cache behavior.  The idea is that per-cpu objects which haven't been
accessed in several seconds should be returned to the cache.  On the other
hand Linux slabs never move objects back to the slabs unless there is
memory pressure on the system.

This behavior is now configurable through the 'spl_kmem_cache_expire'
module option.  The value is a bit mask with the following meaning.

  0x1 - Solaris style cache aging eviction is enabled.
  0x2 - Linux style low memory eviction is enabled.

Both methods may be safely enabled simultaneously, but by default
both are disabled.  It has never been clear if the kmem cache aging
(which has been around from day one) actually does any good.  It has
however been the source of numerous bugs so I wouldn't mind retiring
it entirely.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes zfsonlinux/zfs#1227
Closes #210
2013-01-28 09:34:12 -08:00
Matt Johnston 46a75aadb7 Add cv_wait_io() to account I/O time
Under Linux when a task is waiting on I/O it should call the
io_schedule() function for proper accounting.  The Solaris
cv_wait() function provides no way to specify what the cv
is waiting on therefore cv_wait_io() is introduced.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #206
2013-01-07 10:29:26 -08:00
Brian Behlendorf eb0be2ed46 Removed SPL_AC_3ARGS_INIT_WORK check
All consumers of the kernel delayed work queues have been shifted
over to rely on the taskq implementation.  This compatibility code
can now be removed.  Any new callers which need this functionality
should use the taskq interfaces for delayed work items.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-12-12 09:57:10 -08:00
Brian Behlendorf 33e94ef1dd kmem-cache: Use a taskq for async allocations
Shift the asynchronous allocations over to use the taskq interfaces.
This allows us to abandon the kernels delayed work queue interface
and all the compatibility code it requires.

This code never actually used the delay functionality it was just
done this way to leverage the existing compatibility code.  All that
is required is a thread context to perform the allocation in.  The
only thing clever in this change is that we take advantage of the
preallocated task queue entries to avoid a memory allocation.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-12-12 09:56:54 -08:00
Brian Behlendorf a10287e00d kmem-cache: Use taskqs for ageing
Shift the cache and magazine ageing functionality over to the new
delayed taskq interfaces.  This allows us to abandon the kernels
delayed work queue interface and all the compatibility code it
requires.

However, the delayed taskq interface does not allow us to schedule
a task for a specfic cpu so the ageing code was slightly reworked.
The magazine ageing delay has been directly linked to the cache
ageing function.  The spl_cache_age() function invokes on_each_cpu()
in order to run spl_magazine_age() on each cpu.  It then blocks
waiting for them to complete and promptly reclaims any free slabs.

When restructing the code wasn't the primary goal I think the
new code is far more understable and maintainable.  It also should
help minimize magazine thrashing because free slabs are immediately
released after the magazine is aged.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-12-12 09:56:54 -08:00
Brian Behlendorf d9acd930b5 taskq delay/cancel functionality
Add the ability to dispatch a delayed task to a taskq.  The desired
behavior is for the task to be queued but not executed by a worker
thread until the expiration time is reached.  To achieve this two
new functions were added.

* taskq_dispatch_delay() -

  This function behaves exactly like taskq_dispatch() however it
takes a third 'expire_time' argument.  The caller should pass the
desired time the task should be executed as an absolute value in
jiffies.  The task is guarenteed not to run before this time, it
may run slightly latter if all the worker threads are busy.

* taskq_cancel_id() -

  Given a task id attempt to cancel the task before it gets executed.
This is primarily useful for canceling delay tasks but can be used for
canceling any previously dispatched task.  There are three possible
return values.

  0      - The task was found and canceled before it was executed.
  ENOENT - The task was not found, either it was already run or an
           invalid task id was supplied by the caller.
  EBUSY  - The task is currently executing any may not be canceled.
           This function will block until the task has been completed.

* taskq_wait_all() -

  The taskq_wait_id() function was renamed taskq_wait_all() to more
clearly reflect its actual behavior.  It is only curreny used by
the splat taskq regression tests.

* taskq_wait_id() -

  Historically, the only difference between this function and
taskq_wait() was that you passed the task id.  In both functions you
would block until ALL lower task ids which executed.  This was
semantically correct but could be very slow particularly if there
were delay tasks submitted.

  To better accomidate the delay tasks this function was reimplemnted.
It will now only block until the passed task id has been completed.

This is actually a fairly low risk change for a few reasons.

* Only new ZFS callers will make use of the new interfaces and
  very little common code was changed to support the new functions.

* The existing taskq_wait() implementation was not changed just
  slightly refactored.

* The newly optimized taskq_wait_id() implementation was never
  used by ZFS we can't accidentally introduce a new bug there.

NOTE: This functionality does not exist in the Illumos taskqs.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-12-12 09:54:07 -08:00
Brian Behlendorf aed8671cb0 taskq style, remove #define wrappers
When the taskq implementation was originally written I wrapped all
the API functions in #define's.  This was done as a preventative
measure to ensure that a taskq symbol never conflicted with an
existing kernel symbol.

However, in practice the taskq symbols never conflicted.  The only
major conflicts occured with the kmem cache API.  Since this added
layer of obfuscation never bought us anything for the taskq's I'm
removing it.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-12-12 09:54:07 -08:00
Brian Behlendorf 472a34caff taskq style, convert spaces to soft tabs
Update the taskq implementation to conform with the style used
throughout the rest of the code.  There are no functional
changes in this commit.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-12-12 09:54:07 -08:00
Brian Behlendorf ed3163484d Track emergency object in rbtree
In the initial implementation emergency objects were tracked on a
per-cache list.  The assumption was that under normal operation we
would never allocate more than a handful of these objects.  So the
cost of walking the list during free was expected to be negligible.

However real world usage has shown that emergency objects tend to
be allocated in batches.  A deadlock will be detected and several
thousand emergency objects will be allocated before the original
blocked slab allocation can complete.

Therefore the original list has been replaced by a red black tree
which is sorted by the memory address of each allocated object.
This bounds the worst case insertion and removal time to O(log n)
which minimize contention on the assoicated spin lock.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-11-06 14:54:19 -08:00
Brian Behlendorf 165f13c33a Improved vmem cached deadlock detection
The entire goal of performing the slab allocations asynchronously
is to be able to detect when a vmalloc() deadlocks.  In this case,
and only this case, do we want to start allocating emergency objects.
The trick here is to minimize false positives because the overhead
of tracking emergency objects is far higher than normal slab objects.

With that goal in mind the code was reworked to be less sensitive
to slow allocations by increasing the wait time.  Once a cache is
is marked deadlocked all subsequent allocations which can not be
satisfied with existing cache objects will immediately allocate new
emergency objects.  This behavior persists until the asynchronous
allocation completes and clears the deadlocked flag.

The result of these tweaks is that far fewer emergency objects
get created which is important because this minimizes the cost of
releasing them latter in kmem_cache_free().

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-11-06 14:54:15 -08:00
Brian Behlendorf df870a697f splat: Cleanup headers
Restructure the the SPLAT headers such that each test only
includes the minimal set of headers it requires.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-11-06 14:48:56 -08:00
Brian Behlendorf d2733258d0 Condition variable reference counts
Reference count every entry and exit from the condition variable
functions: cv_wait(), cv_wait_timeout(), cv_signal(), cv_broadcast().

This allows us to safely block in cv_destroy() until all consumers
have been scheduled and are no longer accessing the condition
variable memory.

In addition poison the magic value at the start of cv_destroy() to
ensure there are never any new callers after cv_destroy() is called.
The consumer is responsible for ensuring this never occurs.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-11-06 14:48:55 -08:00
Brian Behlendorf dba79fcbf2 Add KSTAT_TYPE_TXG type
Add a new kstat type for tracking useful statistics about a TXG.
The new KSTAT_TYPE_TXG type can be used to tracks the following
statistics per-txg.

  txg          - Unique txg number
  state        - State (O)pen/(Q)uiescing/(S)yncing/(C)ommitted
  birth;       - Creation time
  nread        - Bytes read
  nwritten;    - Bytes written
  reads        - IOPs read
  writes       - IOPs write
  open_time;   - Length in nanoseconds the txg was open
  quiesce_time - Length in nanoseconds the txg was quiescing
  sync_time;   - Length in nanoseconds the txg was syncing

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-11-02 15:17:40 -07:00
Brian Behlendorf 71c9f0b003 Make kstat.ks_update() callback atomic
Move the kstat ks_update() callback under the ks_lock.  This
enables dynamically sized kstats without modification to the
kstat API.

  * Create a kstat with the KSTAT_FLAG_VIRTUAL flag.
  * Register a ->ks_update() callback which does:
    o Frees any existing ks_data buffer.
    o Set ks_data_size to the kstat array size.
    o Set ks_data to an allocated buffer of size ks_data_size
    o Populate the array of buffers with the required data.

The buffer allocated in the ks_update() callback is guaranteed
to remain allocated and valid while the proc sequence handler
iterates over the buffer.  The lock will not be dropped until
kstat_seq_stop() function is run making it safe for concurrent
access.  To allow the ks_update() callback to perform memory
allocations the lock was changed to a mutex.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-10-23 09:36:19 -07:00
Etienne Dechamps bbdc6ae495 Add interface for file hole punching.
This adds an interface to "punch holes" (deallocate space) in VFS
files. The interface is identical to the Solaris VOP_SPACE interface.
This interface is necessary for TRIM support on file vdevs.

This is implemented using Linux fallocate(FALLOC_FL_PUNCH_HOLE), which
was introduced in 2.6.38. For a brief time before 2.6.38 this was done
using the truncate_range inode operation, which was quickly deprecated.
This patch only supports FALLOC_FL_PUNCH_HOLE.

This adds support for the truncate_range() inode operation to
VOP_SPACE() for file hole punching. This API is deprecated and removed
in 3.5, so it's only useful for old kernels.

On tmpfs, the truncate_range() inode operation translates to
shmem_truncate_range(). Unfortunately, this function expects the end
offset to be inclusive and aligned to the end of a page. If it is not,
the kernel will stop with a BUG_ON().

This patch fixes the issue by adapting to the constraints set forth by
shmem_truncate_range().

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #168
2012-10-04 16:22:07 -07:00
Brian Behlendorf 9b51f21841 Remove TQ_SLEEP -> KM_SLEEP mapping
When the taskq code was originally written it seemed like a good
idea to simply map TQ_SLEEP to KM_SLEEP.  Unfortunately, this
assumed that the TQ_* flags would never confict with any of the
Linux GFP_* flags.  When adding the TQ_PUSHPAGE support in commit
cd5ca4b this invariant was accidentally broken.

Therefore to support TQ_PUSHPAGE, which is needed for Linux, and
prevent any further confusion I have removed this direct mapping.
The TQ_SLEEP, TQ_NOSLEEP, and TQ_PUSHPAGE are no longer defined
in terms of their KM_* counterparts.  Instead a simple mapping
function is introduce to convert TQ_* -> KM_* where needed.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #171
2012-09-12 11:41:42 -07:00
Brian Behlendorf 330fe010e4 Revert "Switch KM_SLEEP to KM_PUSHPAGE"
This reverts commit cd5ca4b2f8
due to conflicts in the higher TQ_ bits which caused incorrect
behavior.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-09-12 10:07:48 -07:00
Brian Behlendorf cb5c2acebb Add KMC_NOEMERGENCY slab flag
Provide a flag to disable the use of emergency objects for a
specific kmem cache.  There may be instances where under no
circumstances should you kmalloc() an emergency object.  For
example, when you cache contains very large objects (>128k).

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-09-07 14:27:03 -07:00
Etienne Dechamps ac8ca67a88 Add DKIOCTRIM for TRIM support.
See dechamps/zfs@cc6cd40ad7 for details.

This harmless addition was merged to simplify testing the ZFS TRIM
support patches.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #167
2012-09-02 14:22:01 -07:00
Brian Behlendorf cd5ca4b2f8 Switch KM_SLEEP to KM_PUSHPAGE
Under certain circumstances the following functions may be called
in a context where KM_SLEEP is unsafe and can result in a deadlocked
system.  To avoid this problem the unconditional KM_SLEEPs are
converted to KM_PUSHPAGEs.  This will prevent them from attempting
to initiate any I/O during direct reclaim.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-08-27 12:00:55 -07:00