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[PATCH] exit_io_context: don't disable irqs

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We don't need to disable irqs to clear current->io_context, it is protected
by ->alloc_lock. Even IF it was possible to submit I/O from IRQ on behalf of
current this irq_disable() can't help: current_io_context() will re-instantiate
->io_context after irq_enable().

We don't need task_lock() or local_irq_disable() to clear ioc->task. This can't
prevent other CPUs from playing with our io_context anyway.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Oleg Nesterov 2006-08-29 09:15:14 +02:00 committed by Jens Axboe
parent 9bf09c2385
commit 25034d7a83
1 changed files with 2 additions and 5 deletions
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7
block/ll_rw_blk.c
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@ -3629,25 +3629,22 @@ EXPORT_SYMBOL(put_io_context);
/* Called by the exitting task */
void exit_io_context(void)
{
unsigned long flags;
struct io_context *ioc;
struct cfq_io_context *cic;
local_irq_save(flags);
task_lock(current);
ioc = current->io_context;
current->io_context = NULL;
ioc->task = NULL;
task_unlock(current);
local_irq_restore(flags);
ioc->task = NULL;
if (ioc->aic && ioc->aic->exit)
ioc->aic->exit(ioc->aic);
if (ioc->cic_root.rb_node != NULL) {
cic = rb_entry(rb_first(&ioc->cic_root), struct cfq_io_context, rb_node);
cic->exit(ioc);
}
put_io_context(ioc);
}