From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <4FF5A4EB.3080502@redhat.com> Date: Thu, 05 Jul 2012 10:30:03 -0400 From: Prarit Bhargava MIME-Version: 1.0 To: John Stultz CC: Linux Kernel , stable@vger.kernel.org, Thomas Gleixner , linux@openhuawei.org Subject: Re: [PATCH 3/3] [RFC] hrtimer: Update hrtimer base offsets each hrtimer_interrupt References: <1341382890-42324-1-git-send-email-johnstul@us.ibm.com> <1341382890-42324-4-git-send-email-johnstul@us.ibm.com> In-Reply-To: <1341382890-42324-4-git-send-email-johnstul@us.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: On 07/04/2012 02:21 AM, John Stultz wrote: > This patch introduces a new funciton which captures the > CLOCK_MONOTONIC time, along with the CLOCK_REALTIME and > CLOCK_BOOTTIME offsets at the same moment. This new function > is then used in place of ktime_get() when hrtimer_interrupt() > is expiring timers. > > This ensures that any changes to realtime or boottime offsets > are noticed and stored into the per-cpu hrtimer base structures, > prior to doing any hrtimer expiration. This should ensure that > timers are not expired early if the offsets changes under us. > > This is useful in the case where clock_was_set() is called from > atomic context and have to schedule the hrtimer base offset update > via a timer, as it provides extra robustness in the face of any > possible timer delay. > > CC: Prarit Bhargava > CC: stable@vger.kernel.org > CC: Thomas Gleixner > CC: linux@openhuawei.org > Signed-off-by: John Stultz Acked-by: Prarit Bhargava P.