From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753634Ab3I0P3V (ORCPT ); Fri, 27 Sep 2013 11:29:21 -0400 Received: from merlin.infradead.org ([205.233.59.134]:56137 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752349Ab3I0P3U (ORCPT ); Fri, 27 Sep 2013 11:29:20 -0400 Date: Fri, 27 Sep 2013 17:29:08 +0200 From: Peter Zijlstra To: Yuanhan Liu Cc: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, linux-tip-commits@vger.kernel.org, Fengguang Wu , Huang Ying , lkp@linux.intel.com, Steven Rostedt Subject: [PATCH] ftrace, sched: Add TRACE_FLAG_PREEMPT_RESCHED Message-ID: <20130927152908.GE15690@laptop.programming.kicks-ass.net> References: <20130927091427.GE24743@yliu-dev.sh.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130927091427.GE24743@yliu-dev.sh.intel.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 Subject: ftrace, sched: Add TRACE_FLAG_PREEMPT_RESCHED From: Peter Zijlstra Date: Fri Sep 27 17:11:00 CEST 2013 Since we now have two need_resched states; trace the two so we can observe discrepancies. Cc: Steven Rostedt Signed-off-by: Peter Zijlstra --- kernel/trace/trace.c | 3 ++- kernel/trace/trace.h | 1 + kernel/trace/trace_output.c | 13 +++++++++++-- 3 files changed, 14 insertions(+), 3 deletions(-) --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1509,7 +1509,8 @@ tracing_generic_entry_update(struct trac #endif ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | - (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0); + (tif_need_resched() ? TRACE_FLAG_NEED_RESCHED : 0) | + (test_preempt_need_resched() ? TRACE_FLAG_PREEMPT_RESCHED : 0); } EXPORT_SYMBOL_GPL(tracing_generic_entry_update); --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -124,6 +124,7 @@ enum trace_flag_type { TRACE_FLAG_NEED_RESCHED = 0x04, TRACE_FLAG_HARDIRQ = 0x08, TRACE_FLAG_SOFTIRQ = 0x10, + TRACE_FLAG_PREEMPT_RESCHED = 0x20, }; #define TRACE_BUF_SIZE 1024 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -618,8 +618,17 @@ int trace_print_lat_fmt(struct trace_seq (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' : '.'; - need_resched = - (entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.'; + + if ((entry->flags & TRACE_FLAG_NEED_RESCHED) && + (entry->flags & TRACE_FLAG_PREEMPT_RESCHED)) + need_resched = 'N'; + else if (entry->flags & TRACE_FLAG_NEED_RESCHED) + need_resched = 'n'; + else if (entry->flags & TRACE_FLAG_PREEMPT_RESCHED) + need_resched = 'p'; + else + need_resched = '.'; + hardsoft_irq = (hardirq && softirq) ? 'H' : hardirq ? 'h' :