From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 12CA3C433FF for ; Tue, 30 Jul 2019 22:40:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E50E8206A2 for ; Tue, 30 Jul 2019 22:40:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388265AbfG3Wkw (ORCPT ); Tue, 30 Jul 2019 18:40:52 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:58696 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388230AbfG3Wku (ORCPT ); Tue, 30 Jul 2019 18:40:50 -0400 Received: from localhost ([127.0.0.1] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1hsanS-0002Nj-AS; Wed, 31 Jul 2019 00:40:42 +0200 Message-Id: <20190730223828.600085866@linutronix.de> User-Agent: quilt/0.65 Date: Wed, 31 Jul 2019 00:33:50 +0200 From: Thomas Gleixner To: LKML Cc: Peter Zijlstra , Ingo Molnar , Sebastian Siewior , Anna-Maria Gleixner , Steven Rostedt , Julia Cartwright Subject: [patch 2/7] timerfd: Prepare for PREEMPT_RT References: <20190730223348.409366334@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Use the hrtimer_cancel_wait_running() synchronization mechanism to prevent priority inversion and live locks on PREEMPT_RT. [ tglx: Split out of combo patch ] Signed-off-by: Anna-Maria Gleixner Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner --- fs/timerfd.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/fs/timerfd.c +++ b/fs/timerfd.c @@ -471,7 +471,11 @@ static int do_timerfd_settime(int ufd, i break; } spin_unlock_irq(&ctx->wqh.lock); - cpu_relax(); + + if (isalarm(ctx)) + hrtimer_cancel_wait_running(&ctx->t.alarm.timer); + else + hrtimer_cancel_wait_running(&ctx->t.tmr); } /*