From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757618AbcBXEah (ORCPT ); Tue, 23 Feb 2016 23:30:37 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:53962 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932458AbcBXEYV (ORCPT ); Tue, 23 Feb 2016 23:24:21 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thomas Gleixner , Peter Zijlstra , John Stultz , linux-m68k@vger.kernel.org, dhowells@redhat.com Subject: [PATCH 4.4 133/137] timerfd: Handle relative timers with CONFIG_TIME_LOW_RES proper Date: Tue, 23 Feb 2016 19:34:24 -0800 Message-Id: <20160224033421.623897691@linuxfoundation.org> X-Mailer: git-send-email 2.7.1 In-Reply-To: <20160224033417.270530882@linuxfoundation.org> References: <20160224033417.270530882@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable 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 Signed-off-by: Greg Kroah-Hartman --- 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; }