Messages in this thread Patch in this message | | | Date | Fri, 28 May 2010 16:15:36 +0200 | From | Piotr Hosowicz <> | Subject | Re: [PATCH] sched_clock: Provide local_clock() and improve documentation |
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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 -- 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/
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