From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757799Ab0E1OPq (ORCPT ); Fri, 28 May 2010 10:15:46 -0400 Received: from 64.mail-out.ovh.net ([91.121.185.65]:49904 "HELO 64.mail-out.ovh.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1755796Ab0E1OPn (ORCPT ); Fri, 28 May 2010 10:15:43 -0400 Message-ID: <4BFFD008.4070909@example.com> Date: Fri, 28 May 2010 16:15:36 +0200 From: Piotr Hosowicz Reply-To: piotr@hosowicz.com Organization: hosowicz.com User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100515 Icedove/3.0.4 MIME-Version: 1.0 To: Peter Zijlstra CC: Andrew Morton , Jens Axboe , Divyesh Shah , Ingo Molnar , LKML , Piotr Hosowicz Subject: Re: [PATCH] sched_clock: Provide local_clock() and improve documentation References: <4BF9EC69.5030709@example.com> <1274777422.5882.591.camel@twins> <20100526160252.325f8357.akpm@linux-foundation.org> <1274942798.27810.3584.camel@twins> <20100526235107.77e66ce0.akpm@linux-foundation.org> <1274945751.27810.3765.camel@twins> <20100527113340.d4afb8fc.akpm@linux-foundation.org> <1275052414.1645.52.camel@laptop> In-Reply-To: <1275052414.1645.52.camel@laptop> Content-Type: text/plain; charset=ISO-8859-2; format=flowed Content-Transfer-Encoding: 8bit X-Ovh-Tracer-Id: 14990512836474859919 X-Ovh-Remote: 83.24.90.132 (dni132.neoplus.adsl.tpnet.pl) X-Ovh-Local: 213.186.33.20 (ns0.ovh.net) X-Spam-Check: DONE|U 0.5/N Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 28.05.2010 15:13, Peter Zijlstra wrote: > On Thu, 2010-05-27 at 11:33 -0700, Andrew Morton wrote: > >> Cool, thanks. You didn't Cc a mailing list :( > > Oops, must have managed to wreck the CC list somewhere, restored LKML. > > How does the below look? Earlier someone (you? I didn't write down) has published such a patch: f4b87dee9 Index: linux-2.6/arch/parisc/kernel/ftrace.c =================================================================== --- linux-2.6.orig/arch/parisc/kernel/ftrace.c +++ linux-2.6/arch/parisc/kernel/ftrace.c @@ -82,7 +82,7 @@ unsigned long ftrace_return_to_handler(u unsigned long ret; pop_return_trace(&trace, &ret); - trace.rettime = cpu_clock(raw_smp_processor_id()); + trace.rettime = local_clock(); ftrace_graph_return(&trace); if (unlikely(!ret)) { @@ -126,7 +126,7 @@ void prepare_ftrace_return(unsigned long return; } - calltime = cpu_clock(raw_smp_processor_id()); + calltime = local_clock(); if (push_return_trace(old, calltime, self_addr, &trace.depth) == -EBUSY) { Index: linux-2.6/include/linux/blkdev.h =================================================================== --- linux-2.6.orig/include/linux/blkdev.h +++ linux-2.6/include/linux/blkdev.h @@ -1213,12 +1213,12 @@ int kblockd_schedule_work(struct request #ifdef CONFIG_BLK_CGROUP static inline void set_start_time_ns(struct request *req) { - req->start_time_ns = sched_clock(); + req->start_time_ns = local_clock(); } static inline void set_io_start_time_ns(struct request *req) { - req->io_start_time_ns = sched_clock(); + req->io_start_time_ns = local_clock(); } static inline uint64_t rq_start_time_ns(struct request *req) Index: linux-2.6/include/linux/sched.h =================================================================== --- linux-2.6.orig/include/linux/sched.h +++ linux-2.6/include/linux/sched.h @@ -1822,6 +1822,7 @@ extern void sched_clock_idle_wakeup_even * clock constructed from sched_clock(): */ extern unsigned long long cpu_clock(int cpu); +extern unsigned long long local_clock(void); extern unsigned long long task_sched_runtime(struct task_struct *task); Index: linux-2.6/kernel/lockdep.c =================================================================== --- linux-2.6.orig/kernel/lockdep.c +++ linux-2.6/kernel/lockdep.c @@ -146,7 +146,7 @@ static DEFINE_PER_CPU(struct lock_class_ static inline u64 lockstat_clock(void) { - return cpu_clock(smp_processor_id()); + return local_clock(); } static int lock_point(unsigned long points[], unsigned long ip) Index: linux-2.6/kernel/perf_event.c =================================================================== --- linux-2.6.orig/kernel/perf_event.c +++ linux-2.6/kernel/perf_event.c @@ -214,7 +214,7 @@ static void perf_unpin_context(struct pe static inline u64 perf_clock(void) { - return cpu_clock(raw_smp_processor_id()); + return local_clock(); } /* Index: linux-2.6/kernel/rcutorture.c =================================================================== --- linux-2.6.orig/kernel/rcutorture.c +++ linux-2.6/kernel/rcutorture.c @@ -239,8 +239,7 @@ static unsigned long rcu_random(struct rcu_random_state *rrsp) { if (--rrsp->rrs_count < 0) { - rrsp->rrs_state += - (unsigned long)cpu_clock(raw_smp_processor_id()); + rrsp->rrs_state += (unsigned long)local_clock(); rrsp->rrs_count = RCU_RANDOM_REFRESH; } rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD; Index: linux-2.6/kernel/sched.c =================================================================== --- linux-2.6.orig/kernel/sched.c +++ linux-2.6/kernel/sched.c @@ -1670,7 +1670,7 @@ static void update_shares(struct sched_d if (root_task_group_empty()) return; - now = cpu_clock(raw_smp_processor_id()); + now = local_clock(); elapsed = now - sd->last_update; if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) { Index: linux-2.6/kernel/sched_clock.c =================================================================== --- linux-2.6.orig/kernel/sched_clock.c +++ linux-2.6/kernel/sched_clock.c @@ -249,6 +249,18 @@ unsigned long long cpu_clock(int cpu) return clock; } +unsigned long long local_clock(void) +{ + unsigned long long clock; + unsigned long flags; + + local_irq_save(flags); + clock = sched_clock_cpu(smp_processor_id()); + local_irq_restore(flags); + + return clock; +} + #else /* CONFIG_HAVE_UNSTABLE_SCHED_CLOCK */ void sched_clock_init(void) @@ -264,12 +276,17 @@ u64 sched_clock_cpu(int cpu) return sched_clock(); } - unsigned long long cpu_clock(int cpu) { return sched_clock_cpu(cpu); } +unsigned long long local_clock(void) +{ + return sched_clock_cpu(0); +} + #endif /* CONFIG_HAVE_UNSTABLE_SCHED_CLOCK */ EXPORT_SYMBOL_GPL(cpu_clock); +EXPORT_SYMBOL_GPL(local_clock); Index: linux-2.6/kernel/trace/trace_clock.c =================================================================== --- linux-2.6.orig/kernel/trace/trace_clock.c +++ linux-2.6/kernel/trace/trace_clock.c @@ -56,7 +56,7 @@ u64 notrace trace_clock_local(void) */ u64 notrace trace_clock(void) { - return cpu_clock(raw_smp_processor_id()); + return local_clock(); } Should I apply it first and then your today's patch or only the today's patch? Regards, Piotr Hosowicz -- Szef TVN24 do dziennikarzy: Kochani, przez dwa lata waliliśmy w obóz rządzący. Tak dalej byc nie może. Jesteśmy telewizją niezależną i to zobowiązuje. Teraz będziemy kopać w opozycję. NP: Mark Knopfler - Hard Shoulder NB: 2.6.34-20100527-2020-gitt-revtd