Commit 41d10da3 authored Oct 16, 2007 by Jeff Moyer Committed by Linus Torvalds Oct 17, 2007

aio: account I/O wait time properly

Some months back I proposed changing the schedule() call in
read_events to an io_schedule():
	http://osdir.com/ml/linux.kernel.aio.general/2006-10/msg00024.html


This was rejected as there are AIO operations that do not initiate
disk I/O.  I've had another look at the problem, and the only AIO
operation that will not initiate disk I/O is IOCB_CMD_NOOP.  However,
this command isn't even wired up!

Given that it doesn't work, and hasn't for *years*, I'm going to
suggest again that we do proper I/O accounting when using AIO.

Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Zach Brown <zach.brown@oracle.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Suparna Bhattacharya <suparna@in.ibm.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent c17ac855

fs/aio.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -303,7 +303,7 @@ static void wait_for_all_aios(struct kioctx *ctx)
		set_task_state(tsk, TASK_UNINTERRUPTIBLE);
		while (ctx->reqs_active) {
		spin_unlock_irq(&ctx->ctx_lock);
		schedule();
		io_schedule();
		set_task_state(tsk, TASK_UNINTERRUPTIBLE);
		spin_lock_irq(&ctx->ctx_lock);
		}
		@@ -323,7 +323,7 @@ ssize_t fastcall wait_on_sync_kiocb(struct kiocb *iocb)
		set_current_state(TASK_UNINTERRUPTIBLE);
		if (!iocb->ki_users)
		break;
		schedule();
		io_schedule();
		}
		__set_current_state(TASK_RUNNING);
		return iocb->ki_user_data;
		@@ -1170,7 +1170,7 @@ retry:
		ret = 0;
		if (to.timed_out) /* Only check after read evt */
		break;
		schedule();
		io_schedule();
		if (signal_pending(tsk)) {
		ret = -EINTR;
		break;

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