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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 0/4] hrtimers: Handle remaining time correctly for CONFIG_TIME_LOW_RES=y
Date: Thu, 14 Jan 2016 16:54:45 -0000	[thread overview]
Message-ID: <20160114163744.582215466@linutronix.de> (raw)

Helge reported, that timerfd returns occasionally remaining time larger than
the relative time which was used to arm the timer. This is caused by the extra
jiffy which we add in hrtimer_start_range_ns() if CONFIG_TIME_LOW_RES=y.

This is not only an issue for timerfd. We have the same problem in
posix-timers and itimers.

This series adds infrastructure to the core to handle that cases and converts
the users over to it.

Thanks,

	tglx
---
 fs/timerfd.c               |    2 -
 include/linux/hrtimer.h    |   34 +++++++++++++++++++++++++--
 kernel/time/hrtimer.c      |   55 ++++++++++++++++++++++++++++++---------------
 kernel/time/itimer.c       |    2 -
 kernel/time/posix-timers.c |    2 -
 kernel/time/timer_list.c   |    2 -
 6 files changed, 72 insertions(+), 25 deletions(-)

WARNING: multiple messages have this Message-ID
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@lists.linux-m68k.org, dhowells@redhat.com
Subject: [patch 0/4] hrtimers: Handle remaining time correctly for CONFIG_TIME_LOW_RES=y
Date: Thu, 14 Jan 2016 16:54:45 -0000	[thread overview]
Message-ID: <20160114163744.582215466@linutronix.de> (raw)

Helge reported, that timerfd returns occasionally remaining time larger than
the relative time which was used to arm the timer. This is caused by the extra
jiffy which we add in hrtimer_start_range_ns() if CONFIG_TIME_LOW_RES=y.

This is not only an issue for timerfd. We have the same problem in
posix-timers and itimers.

This series adds infrastructure to the core to handle that cases and converts
the users over to it.

Thanks,

	tglx
---
 fs/timerfd.c               |    2 -
 include/linux/hrtimer.h    |   34 +++++++++++++++++++++++++--
 kernel/time/hrtimer.c      |   55 ++++++++++++++++++++++++++++++---------------
 kernel/time/itimer.c       |    2 -
 kernel/time/posix-timers.c |    2 -
 kernel/time/timer_list.c   |    2 -
 6 files changed, 72 insertions(+), 25 deletions(-)

             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 Thomas Gleixner [this message]
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 ` [patch 2/4] timerfd: Handle relative timers with CONFIG_TIME_LOW_RES proper Thomas Gleixner
2016-01-17 10:43   ` [tip:timers/urgent] " 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

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