From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755574AbcBWVoy (ORCPT ); Tue, 23 Feb 2016 16:44:54 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:41554 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755279AbcBWVor (ORCPT ); Tue, 23 Feb 2016 16:44:47 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Peter Zijlstra" , linux-m68k@vger.kernel.org, dhowells@redhat.com, "Thomas Gleixner" , "John Stultz" Date: Tue, 23 Feb 2016 21:42:03 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 03/67] timerfd: Handle relative timers with CONFIG_TIME_LOW_RES proper In-Reply-To: X-SA-Exim-Connect-IP: 92.40.248.141 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.78-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Gleixner commit b62526ed11a1fe3861ab98d40b7fdab8981d788a upstream. 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-and-tested-by: Helge Deller Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Cc: John Stultz Cc: linux-m68k@lists.linux-m68k.org Cc: dhowells@redhat.com Link: http://lkml.kernel.org/r/20160114164159.354500742@linutronix.de Signed-off-by: Thomas Gleixner [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- fs/timerfd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/timerfd.c +++ b/fs/timerfd.c @@ -123,7 +123,7 @@ static ktime_t timerfd_get_remaining(str { ktime_t remaining; - remaining = hrtimer_expires_remaining(&ctx->tmr); + remaining = hrtimer_expires_remaining_adjusted(&ctx->tmr); return remaining.tv64 < 0 ? ktime_set(0, 0): remaining; }