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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A0000C433EF for ; Tue, 19 Oct 2021 19:08:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7B53561260 for ; Tue, 19 Oct 2021 19:08:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234959AbhJSTK3 (ORCPT ); Tue, 19 Oct 2021 15:10:29 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:47584 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231355AbhJSTK1 (ORCPT ); Tue, 19 Oct 2021 15:10:27 -0400 Date: Tue, 19 Oct 2021 21:08:11 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1634670492; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=C8ColJKHoH+Yv5W5/AqrBFjrh4Kywtp5uxBkpUzYiy4=; b=1Vb4Mfh/LYR+wo4LldMpubI032U0pbAlkqPtK3VKJL0q9oPTVYe6AgxtxEiFoeTNyJdPpD icMFJDjTvLf2FjKHu1P8LA+MDG+Ye1wL6mxyWk4aaVEP9W9WWDAan8DXLnDEV5YL0CnqGp TVef2YWA0fTDn/S5gjklAgIG/Stuan/NH0GgdQXPvYyIaE34A6RpBG+ube0AQ7U3wWkCFN ENs8bArvjAwlQJBmH8nhpX+Pl9m3Qy2z5lM6iCMAOuZVJmxHRTjrpA/5RUrMRBLbI8Zg1B /sSpv1lIRQukU7vhkcigZIpFXXGQquaVFwWDzaAKFWLTpFSGDtEJOKkwsfvnxA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1634670492; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=C8ColJKHoH+Yv5W5/AqrBFjrh4Kywtp5uxBkpUzYiy4=; b=BqDey9nnfD5VLaaJijO59ydfW3kch+qR/dnydDa/N2xaOgTLSh6ZpmC4re6efSOpqFa7Ep 7h+401e6/IET/6CA== From: Sebastian Andrzej Siewior To: syzbot Cc: bristot@redhat.com, bsegall@google.com, dietmar.eggemann@arm.com, gor@linux.ibm.com, jgross@suse.com, juri.lelli@redhat.com, linux-kernel@vger.kernel.org, mgorman@suse.de, mingo@kernel.org, mingo@redhat.com, namit@vmware.com, peterz@infradead.org, rdunlap@infradead.org, rostedt@goodmis.org, syzkaller-bugs@googlegroups.com, vincent.guittot@linaro.org Subject: Re: [syzbot] possible deadlock in wake_up_all_idle_cpus Message-ID: <20211019190811.ubam63tfv33c7lmx@linutronix.de> References: <000000000000cf252605ce67014a@google.com> <00000000000041567305ce80b8af@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <00000000000041567305ce80b8af@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Does this do anything useful? Signed-off-by: Sebastian Andrzej Siewior --- kernel/smp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/smp.c b/kernel/smp.c index ad0b68a3a3d36..b3bf528fa14d3 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -1170,14 +1170,14 @@ void wake_up_all_idle_cpus(void) { int cpu; - cpus_read_lock(); + migrate_disable(); for_each_online_cpu(cpu) { if (cpu == raw_smp_processor_id()) continue; wake_up_if_idle(cpu); } - cpus_read_unlock(); + migrate_enable(); } EXPORT_SYMBOL_GPL(wake_up_all_idle_cpus); -- 2.33.0