From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 474F52139C6 for ; Fri, 2 Aug 2024 15:10:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722611446; cv=none; b=FQJR8+ttCmMmdQfIGXztGSIfY0L3BdqvzBAKRYMEMTr9hDvsIW8KmOf5VOqAo/7qzx99bCt9yJU4EfP24Fz/BlgAGU6L2I0CcHem+Ha4n2llM7A0eViO9JInkLXT2s8y6n4sCvzpss19FoCL91PsizzDehDZu0bk9P+1RQCYVrU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722611446; c=relaxed/simple; bh=IDUSoDSA7+eKJmWJ4xQGsFqXwG6c85Uc0U67D1FRy78=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=TvaJqAXGb9Zt1CcKDqwU8e+dFmXe+WG58JuXQg4AWGi94GtC/ADu1wQwb9OyQh2fPYQA7rVksVTdDaq9x0Bqdj/XrDtxbTEvgw1nEHqa8dw0jSXloDqKBCacikaf6oun0AQOrs4zDM7+bZIrUYAgY1N5npeTjJl012M3zyEiaTw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=J96PUZPR; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="J96PUZPR" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=1xrY8J73JFNH+hYMm5thHFxWWB+RC04sPoM6FBOH12o=; b=J96PUZPRnXrA2N3nGlKF8ZGtmK nuyxU8W8u8e7YPlC9lMDpd/EwVxlCN5xSLUlyPPnbHXXj24JCMXSJyd6iIUEheLsY+MSca8d7wgSL QHphJ+E9MiwUM0dXDL5JG8+VesKhHOgS3kvQLtrGB+Td0XsvfBz7kCj+5DRVnSrb5SWIeoywLoJvZ E00/FHX4rCKGz0/F9f37ef9PCpLYPgrtnbtQ5TE0I1Nor44aOj+rU/L6V90YZPi7pLYzKF2s0gGWz Bf+e06hdW06bve2is2RRBNCMmgwnNXRV3Rti1jb5twleVBBOfmvzc4fMB/9A76h1maieYbJ7dZcMm WJ6yiSjg==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.97.1 #2 (Red Hat Linux)) id 1sZtvW-000000018kg-3dRp; Fri, 02 Aug 2024 15:10:43 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 780F030049D; Fri, 2 Aug 2024 17:10:42 +0200 (CEST) Date: Fri, 2 Aug 2024 17:10:42 +0200 From: Peter Zijlstra To: "Luis Claudio R. Goncalves" Cc: Ingo Molnar , Will Deacon , Waiman Long , Boqun Feng , linux-kernel@vger.kernel.org Subject: Re: [PATCH V2] lockdep: suggest the fix for "lockdep bfs error:-1" on print_bfs_bug Message-ID: <20240802151042.GM39708@noisy.programming.kicks-ass.net> 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: On Tue, Jul 30, 2024 at 02:45:47PM -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 config > switch LOCKDEP_CIRCULAR_QUEUE_BITS should fix the warning. > > Preface the scary backtrace 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 > ... > > Reviewed-by: Boqun Feng > Reviewed-by: Waiman Long > Signed-off-by: Luis Claudio R. Goncalves Thanks! > --- > > Changes in v2: > - removed extra space from the if condition. > > 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) > + pr_warn("Increase LOCKDEP_CIRCULAR_QUEUE_BITS to avoid this warning:\n"); > + > WARN(1, "lockdep bfs error:%d\n", ret); > } > > -- > 2.45.2 >