- 21 3月, 2012 2 次提交
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由 Al Viro 提交于
we can do that right in __put_ioctx(); as the result, the loop in ioctx_alloc() can be killed. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 10 3月, 2012 2 次提交
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由 Al Viro 提交于
Current code has put_ioctx() called asynchronously from aio_fput_routine(); that's done *after* we have killed the request that used to pin ioctx, so there's nothing to stop io_destroy() waiting in wait_for_all_aios() from progressing. As the result, we can end up with async call of put_ioctx() being the last one and possibly happening during exit_mmap() or elf_core_dump(), neither of which expects stray munmap() being done to them... We do need to prevent _freeing_ ioctx until aio_fput_routine() is done with that, but that's all we care about - neither io_destroy() nor exit_aio() will progress past wait_for_all_aios() until aio_fput_routine() does really_put_req(), so the ioctx teardown won't be done until then and we don't care about the contents of ioctx past that point. Since actual freeing of these suckers is RCU-delayed, we don't need to bump ioctx refcount when request goes into list for async removal. All we need is rcu_read_lock held just over the ->ctx_lock-protected area in aio_fput_routine(). Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk> Reviewed-by: NJeff Moyer <jmoyer@redhat.com> Acked-by: NBenjamin LaHaise <bcrl@kvack.org> Cc: stable@vger.kernel.org Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Al Viro 提交于
Have ioctx_alloc() return an extra reference, so that caller would drop it on success and not bother with re-grabbing it on failure exit. The current code is obviously broken - io_destroy() from another thread that managed to guess the address io_setup() would've returned would free ioctx right under us; gets especially interesting if aio_context_t * we pass to io_setup() points to PROT_READ mapping, so put_user() fails and we end up doing io_destroy() on kioctx another thread has just got freed... Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk> Acked-by: NBenjamin LaHaise <bcrl@kvack.org> Reviewed-by: NJeff Moyer <jmoyer@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 06 3月, 2012 1 次提交
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由 Jeff Moyer 提交于
Bart Van Assche reported a hung fio process when either hot-removing storage or when interrupting the fio process itself. The (pruned) call trace for the latter looks like so: fio D 0000000000000001 0 6849 6848 0x00000004 ffff880092541b88 0000000000000046 ffff880000000000 ffff88012fa11dc0 ffff88012404be70 ffff880092541fd8 ffff880092541fd8 ffff880092541fd8 ffff880128b894d0 ffff88012404be70 ffff880092541b88 000000018106f24d Call Trace: schedule+0x3f/0x60 io_schedule+0x8f/0xd0 wait_for_all_aios+0xc0/0x100 exit_aio+0x55/0xc0 mmput+0x2d/0x110 exit_mm+0x10d/0x130 do_exit+0x671/0x860 do_group_exit+0x44/0xb0 get_signal_to_deliver+0x218/0x5a0 do_signal+0x65/0x700 do_notify_resume+0x65/0x80 int_signal+0x12/0x17 The problem lies with the allocation batching code. It will opportunistically allocate kiocbs, and then trim back the list of iocbs when there is not enough room in the completion ring to hold all of the events. In the case above, what happens is that the pruning back of events ends up freeing up the last active request and the context is marked as dead, so it is thus responsible for waking up waiters. Unfortunately, the code does not check for this condition, so we end up with a hung task. Signed-off-by: NJeff Moyer <jmoyer@redhat.com> Reported-by: NBart Van Assche <bvanassche@acm.org> Tested-by: NBart Van Assche <bvanassche@acm.org> Cc: <stable@kernel.org> [3.2.x only] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 14 1月, 2012 1 次提交
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由 Gleb Natapov 提交于
Since commit 080d676d ("aio: allocate kiocbs in batches") iocbs are allocated in a batch during processing of first iocbs. All iocbs in a batch are automatically added to ctx->active_reqs list and accounted in ctx->reqs_active. If one (not the last one) of iocbs submitted by an user fails, further iocbs are not processed, but they are still present in ctx->active_reqs and accounted in ctx->reqs_active. This causes process to stuck in a D state in wait_for_all_aios() on exit since ctx->reqs_active will never go down to zero. Furthermore since kiocb_batch_free() frees iocb without removing it from active_reqs list the list become corrupted which may cause oops. Fix this by removing iocb from ctx->active_reqs and updating ctx->reqs_active in kiocb_batch_free(). Signed-off-by: NGleb Natapov <gleb@redhat.com> Reviewed-by: NJeff Moyer <jmoyer@redhat.com> Cc: stable@kernel.org # 3.2 Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 03 11月, 2011 1 次提交
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由 Jeff Moyer 提交于
In testing aio on a fast storage device, I found that the context lock takes up a fair amount of cpu time in the I/O submission path. The reason is that we take it for every I/O submitted (see __aio_get_req). Since we know how many I/Os are passed to io_submit, we can preallocate the kiocbs in batches, reducing the number of times we take and release the lock. In my testing, I was able to reduce the amount of time spent in _raw_spin_lock_irq by .56% (average of 3 runs). The command I used to test this was: aio-stress -O -o 2 -o 3 -r 8 -d 128 -b 32 -i 32 -s 16384 <dev> I also tested the patch with various numbers of events passed to io_submit, and I ran the xfstests aio group of tests to ensure I didn't break anything. Signed-off-by: NJeff Moyer <jmoyer@redhat.com> Cc: Daniel Ehrenberg <dehrenberg@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 01 11月, 2011 1 次提交
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由 Christopher Yeoh 提交于
The basic idea behind cross memory attach is to allow MPI programs doing intra-node communication to do a single copy of the message rather than a double copy of the message via shared memory. The following patch attempts to achieve this by allowing a destination process, given an address and size from a source process, to copy memory directly from the source process into its own address space via a system call. There is also a symmetrical ability to copy from the current process's address space into a destination process's address space. - Use of /proc/pid/mem has been considered, but there are issues with using it: - Does not allow for specifying iovecs for both src and dest, assuming preadv or pwritev was implemented either the area read from or written to would need to be contiguous. - Currently mem_read allows only processes who are currently ptrace'ing the target and are still able to ptrace the target to read from the target. This check could possibly be moved to the open call, but its not clear exactly what race this restriction is stopping (reason appears to have been lost) - Having to send the fd of /proc/self/mem via SCM_RIGHTS on unix domain socket is a bit ugly from a userspace point of view, especially when you may have hundreds if not (eventually) thousands of processes that all need to do this with each other - Doesn't allow for some future use of the interface we would like to consider adding in the future (see below) - Interestingly reading from /proc/pid/mem currently actually involves two copies! (But this could be fixed pretty easily) As mentioned previously use of vmsplice instead was considered, but has problems. Since you need the reader and writer working co-operatively if the pipe is not drained then you block. Which requires some wrapping to do non blocking on the send side or polling on the receive. In all to all communication it requires ordering otherwise you can deadlock. And in the example of many MPI tasks writing to one MPI task vmsplice serialises the copying. There are some cases of MPI collectives where even a single copy interface does not get us the performance gain we could. For example in an MPI_Reduce rather than copy the data from the source we would like to instead use it directly in a mathops (say the reduce is doing a sum) as this would save us doing a copy. We don't need to keep a copy of the data from the source. I haven't implemented this, but I think this interface could in the future do all this through the use of the flags - eg could specify the math operation and type and the kernel rather than just copying the data would apply the specified operation between the source and destination and store it in the destination. Although we don't have a "second user" of the interface (though I've had some nibbles from people who may be interested in using it for intra process messaging which is not MPI). This interface is something which hardware vendors are already doing for their custom drivers to implement fast local communication. And so in addition to this being useful for OpenMPI it would mean the driver maintainers don't have to fix things up when the mm changes. There was some discussion about how much faster a true zero copy would go. Here's a link back to the email with some testing I did on that: http://marc.info/?l=linux-mm&m=130105930902915&w=2 There is a basic man page for the proposed interface here: http://ozlabs.org/~cyeoh/cma/process_vm_readv.txt This has been implemented for x86 and powerpc, other architecture should mainly (I think) just need to add syscall numbers for the process_vm_readv and process_vm_writev. There are 32 bit compatibility versions for 64-bit kernels. For arch maintainers there are some simple tests to be able to quickly verify that the syscalls are working correctly here: http://ozlabs.org/~cyeoh/cma/cma-test-20110718.tgzSigned-off-by: NChris Yeoh <yeohc@au1.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: <linux-man@vger.kernel.org> Cc: <linux-arch@vger.kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 23 3月, 2011 1 次提交
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由 Roland Dreier 提交于
The test program below will hang because io_getevents() uses add_wait_queue_exclusive(), which means the wake_up() in io_destroy() only wakes up one of the threads. Fix this by using wake_up_all() in the aio code paths where we want to make sure no one gets stuck. // t.c -- compile with gcc -lpthread -laio t.c #include <libaio.h> #include <pthread.h> #include <stdio.h> #include <unistd.h> static const int nthr = 2; void *getev(void *ctx) { struct io_event ev; io_getevents(ctx, 1, 1, &ev, NULL); printf("io_getevents returned\n"); return NULL; } int main(int argc, char *argv[]) { io_context_t ctx = 0; pthread_t thread[nthr]; int i; io_setup(1024, &ctx); for (i = 0; i < nthr; ++i) pthread_create(&thread[i], NULL, getev, ctx); sleep(1); io_destroy(ctx); for (i = 0; i < nthr; ++i) pthread_join(thread[i], NULL); return 0; } Signed-off-by: NRoland Dreier <roland@purestorage.com> Reviewed-by: NJeff Moyer <jmoyer@redhat.com> Cc: <stable@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 10 3月, 2011 3 次提交
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由 Jens Axboe 提交于
This should be useless now that we have on-stack plugging. So lets just kill it. Signed-off-by: NJens Axboe <jaxboe@fusionio.com>
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由 Shaohua Li 提交于
Signed-off-by: NShaohua Li <shaohua.li@intel.com> Signed-off-by: NJens Axboe <jaxboe@fusionio.com>
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由 Jens Axboe 提交于
Code has been converted over to the new explicit on-stack plugging, and delay users have been converted to use the new API for that. So lets kill off the old plugging along with aops->sync_page(). Signed-off-by: NJens Axboe <jaxboe@fusionio.com>
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- 26 2月, 2011 2 次提交
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由 Jan Kara 提交于
A race can occur when io_submit() races with io_destroy(): CPU1 CPU2 io_submit() do_io_submit() ... ctx = lookup_ioctx(ctx_id); io_destroy() Now do_io_submit() holds the last reference to ctx. ... queue new AIO put_ioctx(ctx) - frees ctx with active AIOs We solve this issue by checking whether ctx is being destroyed in AIO submission path after adding new AIO to ctx. Then we are guaranteed that either io_destroy() waits for new AIO or we see that ctx is being destroyed and bail out. Cc: Nick Piggin <npiggin@kernel.dk> Reviewed-by: NJeff Moyer <jmoyer@redhat.com> Signed-off-by: NJan Kara <jack@suse.cz> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Nick Piggin 提交于
aio-dio-invalidate-failure GPFs in aio_put_req from io_submit. lookup_ioctx doesn't implement the rcu lookup pattern properly. rcu_read_lock does not prevent refcount going to zero, so we might take a refcount on a zero count ioctx. Fix the bug by atomically testing for zero refcount before incrementing. [jack@suse.cz: added comment into the code] Reviewed-by: NJeff Moyer <jmoyer@redhat.com> Signed-off-by: NNick Piggin <npiggin@kernel.dk> Signed-off-by: NJan Kara <jack@suse.cz> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 27 1月, 2011 1 次提交
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由 Tejun Heo 提交于
aio_wq isn't used during memory reclaim. Convert to alloc_workqueue() without WQ_MEM_RECLAIM. It's possible to use system_wq but given that the number of work items is determined from userland and the work item may block, enforcing strict concurrency limit would be a good idea. Also, move fput_work to system_wq so that aio_wq is used soley to throttle the max concurrency of aio work items and fput_work doesn't interact with other work items. Signed-off-by: NTejun Heo <tj@kernel.org> Acked-by: NJeff Moyer <jmoyer@redhat.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: linux-aio@kvack.org
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- 17 1月, 2011 1 次提交
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由 Namhyung Kim 提交于
Signed-off-by: NNamhyung Kim <namhyung@gmail.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 14 1月, 2011 2 次提交
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由 Jeff Moyer 提交于
aio_run_iocbs() is not used at all, so get rid of it. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: NJeff Moyer <jmoyer@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Namhyung Kim 提交于
'nr >= min_nr >= 0' always satisfies 'nr >= 0' so the check is unnecesary. Signed-off-by: NNamhyung Kim <namhyung@gmail.com> Acked-by: NJeff Moyer <jmoyer@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 26 10月, 2010 2 次提交
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由 Al Viro 提交于
Clones an existing reference to inode; caller must already hold one. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Chris Mason 提交于
The aio batching code is using igrab to get an extra reference on the inode so it can safely batch. igrab will go ahead and take the global inode spinlock, which can be a bottleneck on large machines doing lots of AIO. In this case, igrab isn't required because we already have a reference on the file handle. It is safe to just bump the i_count directly on the inode. Benchmarking shows this patch brings IOP/s on tons of flash up by about 2.5X. Signed-off-by: NChris Mason <chris.mason@oracle.com>
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- 23 9月, 2010 1 次提交
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由 Jan Kara 提交于
OCFS2 can return ERESTARTSYS from its write function when the process is signalled while waiting for a cluster lock (and the filesystem is mounted with intr mount option). Generally, it seems reasonable to allow filesystems to return this error code from its IO functions. As we must not leak ERESTARTSYS (and similar error codes) to userspace as a result of an AIO operation, we have to properly convert it to EINTR inside AIO code (restarting the syscall isn't really an option because other AIO could have been already submitted by the same io_submit syscall). Signed-off-by: NJan Kara <jack@suse.cz> Reviewed-by: NJeff Moyer <jmoyer@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Zach Brown <zach.brown@oracle.com> Cc: <stable@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 15 9月, 2010 1 次提交
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由 Jeff Moyer 提交于
Tavis Ormandy pointed out that do_io_submit does not do proper bounds checking on the passed-in iocb array: if (unlikely(nr < 0)) return -EINVAL; if (unlikely(!access_ok(VERIFY_READ, iocbpp, (nr*sizeof(iocbpp))))) return -EFAULT; ^^^^^^^^^^^^^^^^^^ The attached patch checks for overflow, and if it is detected, the number of iocbs submitted is scaled down to a number that will fit in the long. This is an ok thing to do, as sys_io_submit is documented as returning the number of iocbs submitted, so callers should handle a return value of less than the 'nr' argument passed in. Reported-by: NTavis Ormandy <taviso@cmpxchg8b.com> Signed-off-by: NJeff Moyer <jmoyer@redhat.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 06 8月, 2010 1 次提交
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由 Satoru Takeuchi 提交于
- sys_io_destroy(): acutually return -EINVAL if the context pointed to is invalidIndex: linux-2.6.33-rc4/fs/aio.c - sys_io_getevents(): An argument specifying timeout is not `when', but `timeout'. - sys_io_getevents(): Should describe what is returned if this syscall succeeds. Signed-off-by: NSatoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com> Reviewed-by: NJeff Moyer <jmoyer@redhat.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 28 5月, 2010 2 次提交
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由 Al Viro 提交于
__aio_put_req() plays sick games with file refcount. What it wants is fput() from atomic context; it's almost always done with f_count > 1, so they only have to deal with delayed work in rare cases when their reference happens to be the last one. Current code decrements f_count and if it hasn't hit 0, everything is fine. Otherwise it keeps a pointer to struct file (with zero f_count!) around and has delayed work do __fput() on it. Better way to do it: use atomic_long_add_unless( , -1, 1) instead of !atomic_long_dec_and_test(). IOW, decrement it only if it's not the last reference, leave refcount alone if it was. And use normal fput() in delayed work. I've made that atomic_long_add_unless call a new helper - fput_atomic(). Drops a reference to file if it's safe to do in atomic (i.e. if that's not the last one), tells if it had been able to do that. aio.c converted to it, __fput() use is gone. req->ki_file *always* contributes to refcount now. And __fput() became static. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Jeff Moyer 提交于
The aio compat code was not converting the struct iovecs from 32bit to 64bit pointers, causing either EINVAL to be returned from io_getevents, or EFAULT as the result of the I/O. This patch passes a compat flag to io_submit to signal that pointer conversion is necessary for a given iocb array. A variant of this was tested by Michael Tokarev. I have also updated the libaio test harness to exercise this code path with good success. Further, I grabbed a copy of ltp and ran the testcases/kernel/syscall/readv and writev tests there (compiled with -m32 on my 64bit system). All seems happy, but extra eyes on this would be welcome. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix CONFIG_COMPAT=n build] Signed-off-by: NJeff Moyer <jmoyer@redhat.com> Reported-by: NMichael Tokarev <mjt@tls.msk.ru> Cc: Zach Brown <zach.brown@oracle.com> Cc: <stable@kernel.org> [2.6.35.1] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 16 12月, 2009 1 次提交
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由 Shaohua Li 提交于
Don't know the reason, but it appears ki_wait field of iocb never gets used. Signed-off-by: NShaohua Li <shaohua.li@intel.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Zach Brown <zach.brown@oracle.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 29 10月, 2009 1 次提交
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由 Jens Axboe 提交于
There's nothing block related about them, the backing device is used by things like NFS etc as well. This gets rid of the need to protect such calls by CONFIG_BLOCK. Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
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- 28 10月, 2009 1 次提交
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由 Jeff Moyer 提交于
Hi, Some workloads issue batches of small I/O, and the performance is poor due to the call to blk_run_address_space for every single iocb. Nathan Roberts pointed this out, and suggested that by deferring this call until all I/Os in the iocb array are submitted to the block layer, we can realize some impressive performance gains (up to 30% for sequential 4k reads in batches of 16). Signed-off-by: NJeff Moyer <jmoyer@redhat.com> Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
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- 23 9月, 2009 1 次提交
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由 H Hartley Sweeten 提交于
As mentioned in Documentation/CodingStyle, move EXPORT* macro's to the line immediately after the closing function brace line. Also, move the __initcall() similarly. Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com> Cc: Zach Brown <zach.brown@oracle.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 22 9月, 2009 1 次提交
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由 Michael S. Tsirkin 提交于
Anyone who wants to do copy to/from user from a kernel thread, needs use_mm (like what fs/aio has). Move that into mm/, to make reusing and exporting easier down the line, and make aio use it. Next intended user, besides aio, will be vhost-net. Acked-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NMichael S. Tsirkin <mst@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 01 7月, 2009 1 次提交
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由 Davide Libenzi 提交于
Change the eventfd interface to de-couple the eventfd memory context, from the file pointer instance. Without such change, there is no clean way to racely free handle the POLLHUP event sent when the last instance of the file* goes away. Also, now the internal eventfd APIs are using the eventfd context instead of the file*. This patch is required by KVM's IRQfd code, which is still under development. Signed-off-by: NDavide Libenzi <davidel@xmailserver.org> Cc: Gregory Haskins <ghaskins@novell.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Avi Kivity <avi@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 20 3月, 2009 2 次提交
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由 Jeff Moyer 提交于
The libaio test harness turned up a problem whereby lookup_ioctx on a bogus io context was returning the 1 valid io context from the list (harness/cases/3.p). Because of that, an extra put_iocontext was done, and when the process exited, it hit a BUG_ON in the put_iocontext macro called from exit_aio (since we expect a users count of 1 and instead get 0). The problem was introduced by "aio: make the lookup_ioctx() lockless" (commit abf137dd). Thanks to Zach for pointing out that hlist_for_each_entry_rcu will not return with a NULL tpos at the end of the loop, even if the entry was not found. Signed-off-by: NJeff Moyer <jmoyer@redhat.com> Acked-by: NZach Brown <zach.brown@oracle.com> Acked-by: NJens Axboe <jens.axboe@oracle.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: <stable@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Davide Libenzi 提交于
Remove a source of fput() call from inside IRQ context. Myself, like Eric, wasn't able to reproduce an fput() call from IRQ context, but Jeff said he was able to, with the attached test program. Independently from this, the bug is conceptually there, so we might be better off fixing it. This patch adds an optimization similar to the one we already do on ->ki_filp, on ->ki_eventfd. Playing with ->f_count directly is not pretty in general, but the alternative here would be to add a brand new delayed fput() infrastructure, that I'm not sure is worth it. Signed-off-by: NDavide Libenzi <davidel@xmailserver.org> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: NJeff Moyer <jmoyer@redhat.com> Cc: Zach Brown <zach.brown@oracle.com> Cc: <stable@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 14 1月, 2009 1 次提交
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由 Heiko Carstens 提交于
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
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- 29 12月, 2008 1 次提交
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由 Jens Axboe 提交于
The mm->ioctx_list is currently protected by a reader-writer lock, so we always grab that lock on the read side for doing ioctx lookups. As the workload is extremely reader biased, turn this into an rcu hlist so we can make lookup_ioctx() lockless. Get rid of the rwlock and use a spinlock for providing update side exclusion. There's usually only 1 entry on this list, so it doesn't make sense to look into fancier data structures. Reviewed-by: NJeff Moyer <jmoyer@redhat.com> Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
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- 27 7月, 2008 1 次提交
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由 Al Viro 提交于
make it atomic_long_t; while we are at it, get rid of useless checks in affs, hfs and hpfs - ->open() always has it equal to 1, ->release() - to 0. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 26 7月, 2008 1 次提交
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由 Oleg Nesterov 提交于
Kill PF_BORROWED_MM. Change use_mm/unuse_mm to not play with ->flags, and do s/PF_BORROWED_MM/PF_KTHREAD/ for a couple of other users. No functional changes yet. But this allows us to do further fixes/cleanups. oom_kill/ptrace/etc often check "p->mm != NULL" to filter out the kthreads, this is wrong because of use_mm(). The problem with PF_BORROWED_MM is that we need task_lock() to avoid races. With this patch we can check PF_KTHREAD directly, or use a simple lockless helper: /* The result must not be dereferenced !!! */ struct mm_struct *__get_task_mm(struct task_struct *tsk) { if (tsk->flags & PF_KTHREAD) return NULL; return tsk->mm; } Note also ecard_task(). It runs with ->mm != NULL, but it's the kernel thread without PF_BORROWED_MM. Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 07 6月, 2008 1 次提交
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由 Oleg Nesterov 提交于
use_mm() was changed to use switch_mm() instead of activate_mm(), since then nobody calls (and nobody should call) activate_mm() with PF_BORROWED_MM bit set. As Jeff Dike pointed out, we can also remove the "old != new" check, it is always true. Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 30 4月, 2008 1 次提交
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由 Thomas Gleixner 提交于
Add calls to the generic object debugging infrastructure and provide fixup functions which allow to keep the system alive when recoverable problems have been detected by the object debugging core code. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Acked-by: NIngo Molnar <mingo@elte.hu> Cc: Greg KH <greg@kroah.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 29 4月, 2008 1 次提交
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由 Jeff Moyer 提交于
The FIXME comments are inaccurate. The locking comment over lookup_ioctx() is wrong. Signed-off-by: NJeff Moyer <jmoyer@redhat.com> Signed-off-by: NZach Brown <zach.brown@oracle.com> Signed-off-by: NShen Feng <shen@cn.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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