From 25034d7a83cf77667f3d65822484b305d4be6b25 Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <oleg@tv-sign.ru>
Date: Tue, 29 Aug 2006 09:15:14 +0200
Subject: [PATCH] [PATCH] exit_io_context: don't disable irqs
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>
---
block/ll_rw_blk.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 57992ae511c2ad..f757ed4132147a 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -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);
}
--
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