to be overly clever and the context switch when the semaphore was busy
was destroying performance. Converting to a simple spin lock bough me
a factor of 50 or so. That said it's still not good enough. Tests
show bad performance and we are still CPU bound. The logical fix is
I need to implement per-cpu hot caches to minimize the SMP contention.
Linux and Solaris both have this, I was hoping to do without but it
looks like that's not to be.
kmem_lock: time (sec) slabs objs hash
kmem_lock: tot/max/calc tot/max/calc size/depth
kmem_lock: 0.022000000 7/6/64 224/177/2048 32768/1
kmem_lock: 0.039000000 13/13/128 416/404/4096 32768/1
kmem_lock: 0.079000000 23/21/256 736/672/8192 32768/1
kmem_lock: 0.158000000 48/47/512 1536/1504/16384 32768/1
kmem_lock: 0.345000000 105/105/1024 3360/3358/32768 32768/2
kmem_lock: 0.760000000 202/200/2048 6464/6400/65536 32768/3
git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@135 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
longer be based on the linux slab but to be its own complete
implementation. The new slab behaves much more like the
Solaris slab than the Linux slab.
git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@132 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
1) Ensure mutex_init() never fails in the case of ENOMEM by retrying
forever. I don't think I've ever seen this happen but it was clear
after code inspection that if it did we would immediately crash.
2) Enable full debugging in check.sh for sanity tests. Might as well
get as much debug as we can in the case of a failure.
3) Reworked list of kmem caches tracked by SPL in to a hash with the
key based on the address of the kmem_cache_t. This should speed
up the constructor/destructor/shrinker lookup needed now for newer
kernel which removed the destructor support.
4) Updated kmem_cache_create to handle the case where CONFIG_SLUB
is defined. The slub would occasionally merge slab caches which
resulted in non-unique keys for our hash lookup in 3). To fix this
we detect if the slub is enabled and then set the needed flag
to prevent this merging from ever occuring.
5) New kernels removed the proc_dir_entry pointer from items
registered by sysctl. This means we can no long be sneaky and
manually insert things in to the sysctl tree simply by walking
the proc tree. So I'm forced to create a seperate tree for
all the things I can't easily support via sysctl interface.
I don't like it but it will do for now.
git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@124 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
working on this branch for the next few days I suggested you work
off of the 0.3.1 tag. The following changes are fairly extensive
and are designed to make the SPL compatible with all kernels in
the range of 2.6.18-2.6.25. There were 13 relevant API changes
between these releases and I have added the needed autoconf tests
to check for them. However, this has not all been tested extensively.
I'll sort of the breakage on Fedora Core 9 and RHEL5 this week.
SPL_AC_TYPE_UINTPTR_T
SPL_AC_TYPE_KMEM_CACHE_T
SPL_AC_KMEM_CACHE_DESTROY_INT
SPL_AC_ATOMIC_PANIC_NOTIFIER
SPL_AC_3ARGS_INIT_WORK
SPL_AC_2ARGS_REGISTER_SYSCTL
SPL_AC_KMEM_CACHE_T
SPL_AC_KMEM_CACHE_CREATE_DTOR
SPL_AC_3ARG_KMEM_CACHE_CREATE_CTOR
SPL_AC_SET_SHRINKER
SPL_AC_PATH_IN_NAMEIDATA
SPL_AC_TASK_CURR
SPL_AC_CTL_UNNUMBERED
git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@119 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
other primitive implementations. Additionally ensure that GFP_ATOMIC
is use for allocations when in interrupt context.
git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@108 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
may not fail. To get this behavior I'd added a retry to the shim layer
even though it is abusive to the VM, at least it should prevent the crash.
Additionally I added a proc counter so I can easily check how often this
is happening. It should be fairly rare, but likely will get worse and
worse the longer the machine has been up.
git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@104 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
- Detailed kmem memory allocation tracking. We can now get on
spl module unload a list of all memory allocations which were
not free'd and where the original alloc was. E.g.
SPL: 15554:632:(spl-kmem.c:442:kmem_fini()) kmem leaked 90/319332 bytes
SPL: 15554:648:(spl-kmem.c:451:kmem_fini()) address size data func:line
SPL: 15554:648:(spl-kmem.c:457:kmem_fini()) ffff8100734b68b8 32 0100000001005a5a __spl_mutex_init:70
SPL: 15554:648:(spl-kmem.c:457:kmem_fini()) ffff8100734b6148 13 &tl->tl_lock __spl_mutex_init:74
SPL: 15554:648:(spl-kmem.c:457:kmem_fini()) ffff81007ac43730 32 0100000001005a5a __spl_mutex_init:70
SPL: 15554:648:(spl-kmem.c:457:kmem_fini()) ffff81007ac437d8 13 &tl->tl_lock __spl_mutex_init:74
- Shift to using rwsems in kmem implmentation, to simply locking and
improve concurency.
- Shift to using rwsems in mutex implementation, additionally ensure we
never sleep in the init function if non-zero preempt_count or
interrupts are disabled as can happen in a slab cache ctor/dtor.
- Other minor formating fixes and such.
TODO:
- Finish the vmem memory allocation tracking
- Vet all other SPL primatives for potential sleeping during *_init. I
suspect the rwlock implemenation does this and should be fixes just
like the mutex implemenation.
git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@95 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
- Replacing all BUG_ON()'s with proper ASSERT()'s
- Using ENTRY,EXIT,GOTO, and RETURN macro to instument call paths
git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@78 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
when necessary to avoid deadlocks. We were seeing the deadlock
when calling kmem_cache_generic_constructor() and then an interrupt
forced us to end up calling kmem_cache_generic_destructor()
which caused our deadlock.
git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@74 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
think this should fix anything but it's a good idea regardless.
- Drop the lock before calling the construct/destructor for the slab
otherwise we can't sleep in a constructor/destructor and for long running
functions we may NMI.
- Do something braindead, but safe for the console debug logs for now.
git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@73 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
- Added liunx block device headers to sunldi.h
- Made __taskq_dispatch safe for interrupt context where it turns out we
need to be useing it.
- Fixed NULL const/dest bug for kmem slab caches
- Places debug __dprintf debugging messages under a spin_lock_irqsave
so it's safe to use then in interrupt handlers. For debugging only!
git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@64 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
stuff which only inclused the getf()/releasef() in to the vnode area
where it will only really be used. These calls allow a user to
grab an open file struct given only the known open fd for a particular
user context. ZFS makes use of these, but they're a bit tricky to
test from within the kernel since you already need the file open
and know the fd. So we basically spook the system calls to setup
the environment we need for the splat test case and verify given
just the know fd we can get the file, create the needed vnode, and
then use the vnode interface as usual to read and write from it.
While I was hacking away I also noticed a NULL termination issue
in the second kobj test case so I fixed that too. In fact, I fixed
a few other things as well but all for the best!
git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@51 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
Adjust kmem slab interface to make a copy of the slab name before
passing it on to the linux slab (we free it latter too)
git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@47 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
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
We've dropped all the linux- prefixes on the file in favor of spl-
which makes more sense. And we've cleaned up some of the includes
so everybody should be including their own dependencies properly.
All a module which wants to use the spl support needs to do in
include spl.h and ensure it has access to Module.symvers.
git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@16 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
behlendo
wartens2