AcoSail/kernel_optimize_test
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[PATCH] file: kill unnecessary timer in fdtable_defer

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free_fdtable_rc() schedules timer to reschedule fddef->wq if
schedule_work() on it returns 0.  However, schedule_work() guarantees that
the target work is executed at least once after the scheduling regardless
of its return value.  0 return simply means that the work was already
pending and thus no further action was required.

Another problem is that it used contant '5' as @expires argument to
mod_timer().

Kill unnecessary fddef->timer.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Tejun Heo 2006-12-06 20:36:01 -08:00 committed by Linus Torvalds
parent e59e2ae2c2
commit 593be07ae8
1 changed files with 2 additions and 27 deletions
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29
fs/file.c
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@ -21,7 +21,6 @@
struct fdtable_defer {
spinlock_t lock;
struct work_struct wq;
struct timer_list timer;
struct fdtable *next;
};
@ -75,22 +74,6 @@ static void __free_fdtable(struct fdtable *fdt)
kfree(fdt);
}
static void fdtable_timer(unsigned long data)
{
struct fdtable_defer *fddef = (struct fdtable_defer *)data;
spin_lock(&fddef->lock);
/*
* If someone already emptied the queue return.
*/
if (!fddef->next)
goto out;
if (!schedule_work(&fddef->wq))
mod_timer(&fddef->timer, 5);
out:
spin_unlock(&fddef->lock);
}
static void free_fdtable_work(struct work_struct *work)
{
struct fdtable_defer *f =
@ -144,13 +127,8 @@ static void free_fdtable_rcu(struct rcu_head *rcu)
spin_lock(&fddef->lock);
fdt->next = fddef->next;
fddef->next = fdt;
/*
* vmallocs are handled from the workqueue context.
* If the per-cpu workqueue is running, then we
* defer work scheduling through a timer.
*/
if (!schedule_work(&fddef->wq))
mod_timer(&fddef->timer, 5);
/* vmallocs are handled from the workqueue context */
schedule_work(&fddef->wq);
spin_unlock(&fddef->lock);
put_cpu_var(fdtable_defer_list);
}
@ -354,9 +332,6 @@ static void __devinit fdtable_defer_list_init(int cpu)
struct fdtable_defer *fddef = &per_cpu(fdtable_defer_list, cpu);
spin_lock_init(&fddef->lock);
INIT_WORK(&fddef->wq, free_fdtable_work);
init_timer(&fddef->timer);
fddef->timer.data = (unsigned long)fddef;
fddef->timer.function = fdtable_timer;
fddef->next = NULL;
}