Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751614AbaBLINl (ORCPT ); Wed, 12 Feb 2014 03:13:41 -0500 Received: from mail-qc0-f173.google.com ([209.85.216.173]:60778 "EHLO mail-qc0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751518AbaBLINh (ORCPT ); Wed, 12 Feb 2014 03:13:37 -0500 Date: Wed, 12 Feb 2014 03:13:33 -0500 From: Tejun Heo To: Linus Torvalds Cc: Dave Chinner , Jens Axboe , Steven Rostedt , Dave Jones , Al Viro , Eric Sandeen , Linux Kernel , xfs@oss.sgi.com Subject: Re: 3.14-rc2 XFS backtrace because irqs_disabled. Message-ID: <20140212081333.GC7984@mtj.dyndns.org> References: <20140212004403.GA17129@redhat.com> <20140212010941.GM18016@ZenIV.linux.org.uk> <20140212040358.GA25327@redhat.com> <20140212042215.GN18016@ZenIV.linux.org.uk> <20140212054043.GB13997@dastard> <20140212055027.GA28502@redhat.com> <20140212061038.GC13997@dastard> <20140212063150.GD13997@dastard> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 11, 2014 at 10:59:58PM -0800, Linus Torvalds wrote: > There's a lot of 200+ byte stack frames in block/blk-core.s, and they > all seem to be of the type perf_trace_block_buffer() - things created > with DECLARE_EVENT_CLASS(), afaik. Why they all have 200+ bytes of > frame, I have no idea. That sounds like a potential disaster too, > although hopefully it's mostly leaf functions - but leaf functions > *deep* in the callchain. Tejun? Steven, why _do_ they end up with such > huge frames? It looks like they're essentially the same for all the automatically generated trace functions. I'm seeing 232 byte stack frame in most of them. If I'm not completely confused by these macros, these are generated by DECLARE_EVENT_CLASS() in include/trace/ftrace.h and contains struct pt_regs in the stack frame which is already 168 bytes, so that seems like the culprit. No idea whether this is something avoidable. At least they shouldn't nest in any way. Steven? Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/