From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752305AbaALSnl (ORCPT ); Sun, 12 Jan 2014 13:43:41 -0500 Received: from terminus.zytor.com ([198.137.202.10]:46245 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752068AbaALSni (ORCPT ); Sun, 12 Jan 2014 13:43:38 -0500 Date: Sun, 12 Jan 2014 10:42:38 -0800 From: tip-bot for John Stultz Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, sboyd@codeaurora.org, john.stultz@linaro.org, w@1wt.eu, khalasa@piap.pl, tglx@linutronix.de, u.kleine-koenig@pengutronix.de Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, sboyd@codeaurora.org, john.stultz@linaro.org, w@1wt.eu, khalasa@piap.pl, u.kleine-koenig@pengutronix.de, tglx@linutronix.de In-Reply-To: <1388704274-5278-2-git-send-email-john.stultz@linaro.org> References: <1388704274-5278-2-git-send-email-john.stultz@linaro.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:core/urgent] sched_clock: Disable seqlock lockdep usage in sched_clock() Git-Commit-ID: 7a06c41cbec33c6dbe7eec575c61986122617408 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.1 (terminus.zytor.com [127.0.0.1]); Sun, 12 Jan 2014 10:42:44 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 7a06c41cbec33c6dbe7eec575c61986122617408 Gitweb: http://git.kernel.org/tip/7a06c41cbec33c6dbe7eec575c61986122617408 Author: John Stultz AuthorDate: Thu, 2 Jan 2014 15:11:14 -0800 Committer: Ingo Molnar CommitDate: Sun, 12 Jan 2014 10:14:00 +0100 sched_clock: Disable seqlock lockdep usage in sched_clock() Unfortunately the seqlock lockdep enablement can't be used in sched_clock(), since the lockdep infrastructure eventually calls into sched_clock(), which causes a deadlock. Thus, this patch changes all generic sched_clock() usage to use the raw_* methods. Acked-by: Linus Torvalds Reviewed-by: Stephen Boyd Reported-by: Krzysztof Hałasa Signed-off-by: John Stultz Cc: Uwe Kleine-König Cc: Willy Tarreau Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1388704274-5278-2-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar --- kernel/time/sched_clock.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c index 68b7993..0abb364 100644 --- a/kernel/time/sched_clock.c +++ b/kernel/time/sched_clock.c @@ -74,7 +74,7 @@ unsigned long long notrace sched_clock(void) return cd.epoch_ns; do { - seq = read_seqcount_begin(&cd.seq); + seq = raw_read_seqcount_begin(&cd.seq); epoch_cyc = cd.epoch_cyc; epoch_ns = cd.epoch_ns; } while (read_seqcount_retry(&cd.seq, seq)); @@ -99,10 +99,10 @@ static void notrace update_sched_clock(void) cd.mult, cd.shift); raw_local_irq_save(flags); - write_seqcount_begin(&cd.seq); + raw_write_seqcount_begin(&cd.seq); cd.epoch_ns = ns; cd.epoch_cyc = cyc; - write_seqcount_end(&cd.seq); + raw_write_seqcount_end(&cd.seq); raw_local_irq_restore(flags); }