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 61A1E78B50 for ; Mon, 29 Jul 2024 16:53:40 +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=1722272023; cv=none; b=bV9z3+Zf/c4IAyM9RpWnmH4vBQ2rTmxgSEMM/vDq7dINK1ubBlnYUzfJv1moqRW0LV1AC//qeeUj/wNy/S88Rdt16wAoMbA9B4rHB6es5M6aP2RuusSnpD6Od1itzRUlSHF7oKx+XVY04iq5yFuiLAPqTZUyQlTV/vqD/spo71c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722272023; c=relaxed/simple; bh=p+N8Ve5P1Ip05fYcKq9Z0+kWjejsON2Cg4gjMupfgNM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ETYmVHIp/4ckoom9HgTgRhndWf2Mb1AG6IfUi2S8wtC+ruZWOuG3FJZopgHks3vK1V6DO9VivbeIOSQWPP3SMgNLBE+O0oF666CPUcFzmjNSdQk2AMhCoDYh6pVNLyIncIbTN3mbtHd6Ci8Hhk4MbE/D+t4OL7JKGQXkdrmPvuI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none 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=V61BRB7P; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none 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="V61BRB7P" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1722272020; 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=1B0+0v9UoO752ShDZ+sUoeYQDHn6i5gDwvgX32wEnDQ=; b=V61BRB7POaK0qEiQNmMIurZTAu4H4DpCAEQauPwREk0YSwdO9CldwNeCRM5+uvqMXGlnGT nkpPF5fKgWwSzrDu8KuAzTPfg7afgYnFsuXP/u0XvUFiMi98AID9sjppzMkr5ILaNoi0R9 lzxmZ6pEhS4Q3afIqqMOG8U/mGQisAA= 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-671-1qvuAJt7OVW_3YsQIYnIDw-1; Mon, 29 Jul 2024 12:53:37 -0400 X-MC-Unique: 1qvuAJt7OVW_3YsQIYnIDw-1 Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (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 03D111955D50; Mon, 29 Jul 2024 16:53:36 +0000 (UTC) Received: from localhost (unknown [10.22.34.81]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id CBEE71955D42; Mon, 29 Jul 2024 16:53:34 +0000 (UTC) Date: Mon, 29 Jul 2024 13:53:33 -0300 From: "Luis Claudio R. Goncalves" To: Boqun Feng Cc: Peter Zijlstra , Ingo Molnar , Will Deacon , Waiman Long , linux-kernel@vger.kernel.org Subject: Re: [PATCH] lockdep: suggest the fix for "lockdep bfs error:-1" on print_bfs_bug Message-ID: References: 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: X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 On Fri, Jul 26, 2024 at 02:24:28PM -0700, Boqun Feng wrote: > On Thu, Jul 25, 2024 at 03:45:57PM -0300, Luis Claudio R. Goncalves wrote: > > When lockdep fails while performing the Breadth-first-search operation > > due to lack of memory, hint that increasing the value of the configuration > > switch LOCKDEP_CIRCULAR_QUEUE_BITS should fix the warning. > > > > Preface the scary bactrace with the suggestion: > > > > [ 163.849242] Increase LOCKDEP_CIRCULAR_QUEUE_BITS to avoid this warning: > > [ 163.849248] ------------[ cut here ]------------ > > [ 163.849250] lockdep bfs error:-1 > > [ 163.849263] WARNING: CPU: 24 PID: 2454 at kernel/locking/lockdep.c:2091 print_bfs_bug+0x27/0x40 > > ... > > > > Signed-off-by: Luis Claudio R. Goncalves > > --- > > kernel/locking/lockdep.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c > > index 58c88220a478a..1cf6d9fdddc9c 100644 > > --- a/kernel/locking/lockdep.c > > +++ b/kernel/locking/lockdep.c > > @@ -2067,6 +2067,9 @@ static noinline void print_bfs_bug(int ret) > > /* > > * Breadth-first-search failed, graph got corrupted? > > */ > > + if (ret == BFS_EQUEUEFULL) > > This line has an extra space after "ret", but otherwise it looks fine. Should I send a v2 of the patch with the extra whitespace removed? Luis > Reviewed-by: Boqun Feng > > Regards, > Boqun > > > + pr_warn("Increase LOCKDEP_CIRCULAR_QUEUE_BITS to avoid this warning:\n"); > > + > > WARN(1, "lockdep bfs error:%d\n", ret); > > } > > > > -- > > 2.45.2 > > > ---end quoted text---