All of lore.kernel.org
 help / color / mirror / Atom feed
From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Helge Deller <deller@gmx.de>,
	John Stultz <john.stultz@linaro.org>,
	linux-m68k@vger.kernel.org, dhowells@redhat.com
Subject: [patch 2/4] timerfd: Handle relative timers with CONFIG_TIME_LOW_RES proper
Date: Thu, 14 Jan 2016 16:54:46 -0000	[thread overview]
Message-ID: <20160114164159.354500742@linutronix.de> (raw)
In-Reply-To: <20160114163744.582215466@linutronix.de>

[-- Attachment #1: timerfd--Handle-relative-timers-with-CONFIG_TIME_LOW_RES-proper.patch --]
[-- Type: text/plain, Size: 960 bytes --]

Helge reported that a relative timer can return a remaining time larger than
the programmed relative time on parisc and other architectures which have
CONFIG_TIME_LOW_RES set. This happens because we add a jiffie to the resulting
expiry time to prevent short timeouts.

Use the new function hrtimer_expires_remaining_adjusted() to calculate the
remaining time. It takes that extra added time into account for relative
timers.

Reported-by: Helge Deller <deller@gmx.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 fs/timerfd.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/timerfd.c
+++ b/fs/timerfd.c
@@ -153,7 +153,7 @@ static ktime_t timerfd_get_remaining(str
 	if (isalarm(ctx))
 		remaining = alarm_expires_remaining(&ctx->t.alarm);
 	else
-		remaining = hrtimer_expires_remaining(&ctx->t.tmr);
+		remaining = hrtimer_expires_remaining_adjusted(&ctx->t.tmr);
 
 	return remaining.tv64 < 0 ? ktime_set(0, 0): remaining;
 }

  parent reply	other threads:[~2016-01-14 16:55 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-14 16:54 [patch 0/4] hrtimers: Handle remaining time correctly for CONFIG_TIME_LOW_RES=y Thomas Gleixner
2016-01-14 16:54 ` Thomas Gleixner
2016-01-14 16:54 ` [patch 1/4] hrtimer: Handle remaining time proper for TIME_LOW_RES Thomas Gleixner
2016-01-14 16:54   ` Thomas Gleixner
2016-01-16 18:36   ` Helge Deller
2016-01-16 18:36     ` Helge Deller
2016-01-16 18:36   ` Helge Deller
2016-01-17 10:42   ` [tip:timers/urgent] " tip-bot for Thomas Gleixner
2016-01-14 16:54 ` Thomas Gleixner [this message]
2016-01-17 10:43   ` [tip:timers/urgent] timerfd: Handle relative timers with CONFIG_TIME_LOW_RES proper tip-bot for Thomas Gleixner
2016-01-14 16:54 ` [patch 2/4] " Thomas Gleixner
2016-01-14 16:54 ` [patch 3/4] posix-timers: " Thomas Gleixner
2016-01-14 16:54   ` Thomas Gleixner
2016-01-17 10:43   ` [tip:timers/urgent] " tip-bot for Thomas Gleixner
2016-01-14 16:54 ` [patch 4/4] itimers: " Thomas Gleixner
2016-01-14 16:54 ` Thomas Gleixner
2016-01-17 10:43   ` [tip:timers/urgent] " tip-bot for Thomas Gleixner

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20160114164159.354500742@linutronix.de \
    --to=tglx@linutronix.de \
    --cc=deller@gmx.de \
    --cc=dhowells@redhat.com \
    --cc=john.stultz@linaro.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-m68k@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=peterz@infradead.org \
    --subject='Re: [patch 2/4] timerfd: Handle relative timers with CONFIG_TIME_LOW_RES proper' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.