Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761800AbXH3A5Z (ORCPT ); Wed, 29 Aug 2007 20:57:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754839AbXH3A5R (ORCPT ); Wed, 29 Aug 2007 20:57:17 -0400 Received: from h151.mvista.com ([63.81.120.158]:40137 "EHLO gateway-1237.mvista.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751712AbXH3A5Q (ORCPT ); Wed, 29 Aug 2007 20:57:16 -0400 Subject: Re: [PATCH 1/2] Adds full stack to critical-section tracing From: Daniel Walker To: Gregory Haskins Cc: mingo@elte.hu, linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20070810141413.12966.13475.stgit@lsg> References: <20070810140745.12966.8464.stgit@lsg> <20070810141413.12966.13475.stgit@lsg> Content-Type: text/plain Date: Wed, 29 Aug 2007 17:48:12 -0700 Message-Id: <1188434892.26038.23.camel@dhcp193.mvista.com> Mime-Version: 1.0 X-Mailer: Evolution 2.10.3 (2.10.3-2.fc7) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2036 Lines: 54 On Fri, 2007-08-10 at 08:14 -0600, Gregory Haskins wrote: > --- > > include/linux/sched.h | 7 +++++-- > kernel/latency_trace.c | 18 +++++++++++------- > 2 files changed, 16 insertions(+), 9 deletions(-) > > diff --git a/include/linux/sched.h b/include/linux/sched.h > index 8ebb43c..233d26c 100644 > --- a/include/linux/sched.h > +++ b/include/linux/sched.h > @@ -1306,10 +1306,13 @@ struct task_struct { > #endif > > #define MAX_PREEMPT_TRACE 25 > +#define MAX_PREEMPT_TRACE_DEPTH 5 > > #ifdef CONFIG_PREEMPT_TRACE > - unsigned long preempt_trace_eip[MAX_PREEMPT_TRACE]; > - unsigned long preempt_trace_parent_eip[MAX_PREEMPT_TRACE]; > + struct { > + struct stack_trace trace; > + unsigned long data[MAX_PREEMPT_TRACE_DEPTH]; > + } preempt_trace[MAX_PREEMPT_TRACE]; These changes need some fixing .. The "struct stack_trace" infrastructure is based on CONFIG_STACKTRACE , so at least you would want to ifdef your changes on that config options .. I modified you patch to include the ifdefs, ftp://source.mvista.com/pub/dwalker/misc/debug-preempt-5-levels-of-stack-frames.patch The other problem I noticed is that the save_stack_trace(trace); seems kind of heavy weight to be calling from inside add_preempt_count. If your only going to a depth of 5 you could potentially use there macros, #ifdef CONFIG_FRAME_POINTER # ifndef CONFIG_ARM # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0)) # define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1)) # define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2)) # define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3)) # define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4)) # define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5)) # else Daniel - 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/