Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754707AbYKQWTz (ORCPT ); Mon, 17 Nov 2008 17:19:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752025AbYKQWTr (ORCPT ); Mon, 17 Nov 2008 17:19:47 -0500 Received: from ozlabs.org ([203.10.76.45]:34813 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752020AbYKQWTq (ORCPT ); Mon, 17 Nov 2008 17:19:46 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <18721.60712.438025.564030@cargo.ozlabs.ibm.com> Date: Tue, 18 Nov 2008 09:16:08 +1100 From: Paul Mackerras To: Steven Rostedt Cc: LKML , Benjamin Herrenschmidt , linuxppc-dev@ozlabs.org, Linus Torvalds , Andrew Morton , Ingo Molnar , Thomas Gleixner Subject: Re: Large stack usage in fs code (especially for PPC64) In-Reply-To: References: X-Mailer: VM 8.0.9 under Emacs 22.2.1 (i486-pc-linux-gnu) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1549 Lines: 34 Steven Rostedt writes: > Here's my stack after boot up with CONFIG_IRQSTACKS set. Seems that > softirqs still use the same stack as the process. They shouldn't. I don't see do_softirq in the trace, though. Which functions did you think would be run in a softirq? It looks to me like the deepest 10 or so functions are called at hard irq level, within hrtimer_interrupt called from timer_interrupt. > root@electra ~> cat /debug/tracing/stack_trace > Depth Size Location (59 entries) > ----- ---- -------- > 0) 12384 192 ftrace_call+0x4/0x14 > 1) 12192 128 .sched_clock+0x20/0x60 > 2) 12064 128 .sched_clock_cpu+0x34/0x50 > 3) 11936 144 .cpu_clock+0x3c/0xa0 > 4) 11792 144 .get_timestamp+0x2c/0x50 > 5) 11648 144 .__touch_softlockup_watchdog+0x3c/0x60 > 6) 11504 192 .softlockup_tick+0xe4/0x220 > 7) 11312 128 .run_local_timers+0x34/0x50 > 8) 11184 160 .update_process_times+0x44/0xb0 > 9) 11024 176 .tick_sched_timer+0x8c/0x120 > 10) 10848 160 .__run_hrtimer+0xd8/0x130 > 11) 10688 240 .hrtimer_interrupt+0x16c/0x220 > 12) 10448 160 .timer_interrupt+0xcc/0x110 > 13) 10288 96 decrementer_common+0xe0/0x100 Paul. -- 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/