[PATCH 2/4] timerfd: Move repeated logic into timefd_rearm()

From: Anton Vorontsov
Date: Sun Sep 02 2012 - 01:48:34 EST


This patch introduces timerfd_rearm(), this small helper is used to
forward and restart the hrtimer.

This small refactoring would be also useful if/when we'll add other
backend for timerfd (like deferrable timers), so we won't need to
duplicate the code more.

Signed-off-by: Anton Vorontsov <anton.vorontsov@xxxxxxxxxx>
---
fs/timerfd.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/fs/timerfd.c b/fs/timerfd.c
index dffeb37..ecfb3f3 100644
--- a/fs/timerfd.c
+++ b/fs/timerfd.c
@@ -178,6 +178,14 @@ static unsigned int timerfd_poll(struct file *file, poll_table *wait)
return events;
}

+static u64 timerfd_rearm(struct timerfd_ctx *ctx)
+{
+ u64 orun = hrtimer_forward_now(&ctx->tmr, ctx->tintv) - 1;
+
+ hrtimer_restart(&ctx->tmr);
+ return orun;
+}
+
static ssize_t timerfd_read(struct file *file, char __user *buf, size_t count,
loff_t *ppos)
{
@@ -214,9 +222,7 @@ static ssize_t timerfd_read(struct file *file, char __user *buf, size_t count,
* callback to avoid DoS attacks specifying a very
* short timer period.
*/
- ticks += hrtimer_forward_now(&ctx->tmr,
- ctx->tintv) - 1;
- hrtimer_restart(&ctx->tmr);
+ ticks += timerfd_rearm(ctx);
}
ctx->expired = 0;
ctx->ticks = 0;
@@ -355,9 +361,7 @@ SYSCALL_DEFINE2(timerfd_gettime, int, ufd, struct itimerspec __user *, otmr)
spin_lock_irq(&ctx->wqh.lock);
if (ctx->expired && ctx->tintv.tv64) {
ctx->expired = 0;
- ctx->ticks +=
- hrtimer_forward_now(&ctx->tmr, ctx->tintv) - 1;
- hrtimer_restart(&ctx->tmr);
+ ctx->ticks += timerfd_rearm(ctx);
}
kotmr.it_value = ktime_to_timespec(timerfd_get_remaining(ctx));
kotmr.it_interval = ktime_to_timespec(ctx->tintv);
--
1.7.11.5

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