Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751916AbaA2OIA (ORCPT ); Wed, 29 Jan 2014 09:08:00 -0500 Received: from merlin.infradead.org ([205.233.59.134]:51590 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751477AbaA2OHs (ORCPT ); Wed, 29 Jan 2014 09:07:48 -0500 Date: Wed, 29 Jan 2014 15:07:44 +0100 From: Peter Zijlstra To: Dave Jones , Linux Kernel Subject: Re: task_ctx_sched_out WARN_ON triggered. Message-ID: <20140129140744.GF9636@twins.programming.kicks-ass.net> References: <20140109154707.GB3714@redhat.com> <20140110104837.GL31570@twins.programming.kicks-ass.net> <20140121150953.GA2408@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140121150953.GA2408@redhat.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 21, 2014 at 10:09:53AM -0500, Dave Jones wrote: > On Fri, Jan 10, 2014 at 11:48:37AM +0100, Peter Zijlstra wrote: > > On Thu, Jan 09, 2014 at 10:47:07AM -0500, Dave Jones wrote: > > > This is my fuzz tester, but this looks to be part of normal operation, > > > not actually fuzzing a syscall. This looks to be the bit that > > > sets the task_comm name in the child process to 'trinity-cN'. Which appears to have > > > succeeded judging by the Comm:, but the follow-on perf stuff seems to > > > be screwed up. > > > > > > WARNING: CPU: 1 PID: 13500 at kernel/events/core.c:2379 task_ctx_sched_out+0x6b/0x80() > > > Modules linked in: 8021q garp stp snd_seq_dummy tun fuse rfcomm hidp sctp bnep can_raw scsi_transport_iscsi nfc caif_socket caif af_802154 phonet af_rxrpc bluetooth can_bcm can llc2 pppoe pppox ppp_generic slhc nfnetlink irda ipt_ULOG crc_ccitt rds af_key rose x25 atm netrom appletalk ipx p8023 psnap p8022 llc ax25 cfg80211 rfkill coretemp hwmon x86_pkg_temp_thermal kvm_intel kvm xfs snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep libcrc32c snd_seq e1000e snd_seq_device crct10dif_pclmul crc32c_intel ghash_clmulni_intel snd_pcm ptp snd_page_alloc shpchp snd_timer snd microcode serio_raw soundcore usb_debug pcspkr pps_core > > > CPU: 1 PID: 13500 Comm: trinity-c5 Not tainted 3.13.0-rc7+ #14 > > > ffffffff81a240ac ffff88002e0c7df8 ffffffff816de2ee 0000000000000000 > > > ffff88002e0c7e30 ffffffff81052ddd ffff88024d0975f8 ffff880214d7bb10 > > > 0000000000000282 ffff88015b3b24c0 ffff880214d7bb10 ffff88002e0c7e40 > > > Call Trace: > > > [] dump_stack+0x4e/0x7a > > > [] warn_slowpath_common+0x7d/0xa0 > > > [] warn_slowpath_null+0x1a/0x20 > > > [] task_ctx_sched_out+0x6b/0x80 > > > [] perf_event_comm+0x108/0x260 > > > [] ? perf_event_fork+0x20/0x20 > > > [] ? set_task_comm+0x25/0xc0 > > > [] set_task_comm+0x4f/0xc0 > > > [] SyS_prctl+0x229/0x3d0 > > > [] tracesys+0xdd/0xe2 > > > ---[ end trace d6e98e080907af47 ]--- > > > > > > > > > 2379 if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) > > > 2380 return; > > > > Hmm, you wouldn't happen to have the perf_event_attr for all active > > events, would you? > > dammit. forgot about this, and hit it again overnight. > Is there a handy function in the kernel to dump that struct > that I can call from that path ? Not really; I was kinda hoping you kept traces of the syscalls like Vince's perf-trinity thing does. Let me see if I can make a 'nice' function to dump state though, it might come in handy more often. -- 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/