- 08 Jan, 2006 1 commit
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Benjamin LaHaise authored
Reorder members of the kiocb structure to make sync kiocb setup faster. By setting the elements sequentially, the write combining buffers on the CPU are able to combine the writes into a single burst, which results in fewer cache cycles being consumed, freeing them up for other code. This results in a 10-20KB/s[*] increase on the bw_unix part of LMbench on my test system. * The improvement varies based on what other patches are in the system, as there are a number of bottlenecks, so this number is not absolutely accurate. Signed-off-by:
Benjamin LaHaise <benjamin.c.lahaise@intel.com> Signed-off-by:
Andrew Morton <akpm@osdl.org> Signed-off-by:
Linus Torvalds <torvalds@osdl.org>
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- 13 Nov, 2005 2 commits
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Zach Brown authored
put_ioctx's refcount debugging was doing an atomic_read after dropping its reference when it wasn't the last ref, leaving a tiny race for another freeing thread to sneak into. This shifts the debugging before the ops, uses BUG_ON, and reformats the defines a little. Sadly, moving to inlines increased the code size but this change decreases the code size by a whole 9 bytes :) Signed-off-by:
Zach Brown <zach.brown@oracle.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by:
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Zach Brown authored
Sync iocbs have a life cycle that don't need a kioctx. Their retrying, if any, is done in the context of their owner who has allocated them on the stack. The sole user of a sync iocb's ctx reference was aio_complete() checking for an elevated iocb ref count that could never happen. No path which grabs an iocb ref has access to sync iocbs. If we were to implement sync iocb cancelation it would be done by the owner of the iocb using its on-stack reference. Removing this chunk from aio_complete allows us to remove the entire kioctx instance from mm_struct, reducing its size by a third. On a i386 testing box the slab size went from 768 to 504 bytes and from 5 to 8 per page. Signed-off-by:
Benjamin LaHaise <bcrl@kvack.org> Signed-off-by:
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- 07 Nov, 2005 1 commit
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Zach Brown authored
AIO was adding a new context's max requests to the global total before testing if that resulting total was over the global limit. This let innocent tasks get their new limit tested along with a racing guilty task that was crossing the limit. This serializes the _nr accounting with a spinlock It also switches to using unsigned long for the global totals. Individual contexts are still limited to an unsigned int's worth of requests by the syscall interface. The problem and fix were verified with a simple program that spun creating and destroying a context while holding on to another long lived context. Before the patch a task creating a tiny context could get a spurious EAGAIN if it raced with a task creating a very large context that overran the limit. Signed-off-by:
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- 17 Oct, 2005 1 commit
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Zach Brown authored
lock_kiocb() was introduced to serialize retrying and cancellation. In the process of doing so it tried to sleep waiting for KIF_LOCKED while holding the ctx_lock spinlock. Recent fixes have ensured that multiple concurrent retries won't be attempted for a given iocb. Cancel has other problems and has no significant in-tree users that have been complaining about it. So for the immediate future we'll revert sleeping with the lock held and will address proper cancellation and retry serialization in the future. Signed-off-by:
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- 30 Sep, 2005 1 commit
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Zach Brown authored
Only one of the run or kick path is supposed to put an iocb on the run list. If both of them do it than one of them can end up referencing a freed iocb. The kick path could delete the task_list item from the wait queue before getting the ctx_lock and putting the iocb on the run list. The run path was testing the task_list item outside the lock so that it could catch ki_retry methods that return -EIOCBRETRY *without* putting the iocb on a wait queue and promising to call kick_iocb. This unlocked check could then race with the kick path to cause both to try and put the iocb on the run list. The patch stops the run path from testing task_list by requring that any ki_retry that returns -EIOCBRETRY *must* guarantee that kick_iocb() will be called in the future. aio_p{read,write}, the only in-tree -EIOCBRETRY users, are updated. Signed-off-by:Benjamin LaHaise <bcrl@linux.intel.com> Signed-off-by:
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- 16 Apr, 2005 1 commit
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Linus Torvalds authored
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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