From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 38D242D5C67 for ; Mon, 3 Nov 2025 21:56:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762206999; cv=none; b=pkYpvtIFeAHv2VFtkAId0edP5sSeQMM9G7po8jI/dcijwKQx3nLoaMtnsFdckP+F28aUbupiSEKQZa62iaFSDYJrYbV1UyYiTKn5QYDuzgBwewlGGZIuWTVwDqKLrX0SncE0j+pOgZP/O3akAPKjbYcmiHEPek3GSzcHaJmBraQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762206999; c=relaxed/simple; bh=2aV1jpVS/b2ogJmQ4qWsmxQWZLinZ6L/mG/Y6bMN9ZY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=II0MjbruD+nYMi2h1/BIDUdpEU3uIREB1JhkssX0r2TqvEJFTdIHBGLVvUOwhei+e2AkD//lp0WtBQm+Nw61ISPA+dK+67WuxsB1cFsY/7dUNSLdnavp7E+4FvYjl5sYC+duzCzrOkxqLf7xgfrw/BqsYjsFJinv6d69t6NSYb4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=fjBIOXIt; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="fjBIOXIt" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1762206996; 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=RAHpVp72cuhlEDbcCUsElajB9pDHVuUFNgtsOAXDQ0I=; b=fjBIOXIth/xWIM21r+QGaG0iPJdi1cMXWcK3yLpEfM9Sg6lE7hXVNPzIu0ECKwwDUGMvsn PYsm+MvAu6C0sGgtreQXvaE0qUo+kpl2vxWzzozIkpvy28EonsUbq08ph3W51a63lsZpj/ rBn2OiT6ZC3jyG8U9/AA/n1en3lgEhs= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-595-v8uCwOdxMfiZ8dV4kakhxw-1; Mon, 03 Nov 2025 16:56:33 -0500 X-MC-Unique: v8uCwOdxMfiZ8dV4kakhxw-1 X-Mimecast-MFC-AGG-ID: v8uCwOdxMfiZ8dV4kakhxw_1762206992 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4C9C11956071; Mon, 3 Nov 2025 21:56:31 +0000 (UTC) Received: from pauld.westford.csb (unknown [10.22.90.36]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 6C5BB19560A2; Mon, 3 Nov 2025 21:56:26 +0000 (UTC) Date: Mon, 3 Nov 2025 16:56:23 -0500 From: Phil Auld To: peterz@infradead.org Cc: bsegall@google.com, dietmar.eggemann@arm.com, juri.lelli@redhat.com, linux-kernel@vger.kernel.org, mgorman@suse.de, mingo@redhat.com, frederic@kernel.org, rostedt@goodmis.org, tanghui20@huawei.com, tglx@linutronix.de, vincent.guittot@linaro.org, wangtao554@huawei.com, zhangqiao22@huawei.com, Waiman Long Subject: Re: [PATCH] sched: Increase sched_tick_remote timeout Message-ID: <20251103215623.GA73531@pauld.westford.csb> References: <20250911161300.437944-1-pauld@redhat.com> <20250923104739.GA514793@pauld.westford.csb> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250923104739.GA514793@pauld.westford.csb> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Hi Peter, On Tue, Sep 23, 2025 at 06:47:39AM -0400 Phil Auld wrote: > Hi, > > On Thu, Sep 11, 2025 at 12:13:00PM -0400 Phil Auld wrote: > > Increase the sched_tick_remote WARN_ON timeout to remove false > > positives due to temporarily busy HK cpus. The suggestion > > was 30 seconds to catch really stuck remote tick processing > > but not trigger it too easily. > > > > Signed-off-by: Phil Auld > > Suggested-by: Frederic Weisbecker > > Cc: Peter Zijlstra > > Cc: Frederic Weisbecker > > Frederic ack'd this. Any other thoughts or opinions on this one > character patch? Can we have this timeout increase, please? Thanks, Phil > > Cheers, > Phil > > > > > --- > > kernel/sched/core.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > > index be00629f0ba4..ef90d358252d 100644 > > --- a/kernel/sched/core.c > > +++ b/kernel/sched/core.c > > @@ -5724,7 +5724,7 @@ static void sched_tick_remote(struct work_struct *work) > > * reasonable amount of time. > > */ > > u64 delta = rq_clock_task(rq) - curr->se.exec_start; > > - WARN_ON_ONCE(delta > (u64)NSEC_PER_SEC * 3); > > + WARN_ON_ONCE(delta > (u64)NSEC_PER_SEC * 30); > > } > > curr->sched_class->task_tick(rq, curr, 0); > > > > -- > > 2.51.0 > > > > -- > > --