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668802c257
It was observed that on an Intel x86 system without the ARAT (Always running APIC timer) feature and with fairly large number of CPUs as well as CPUs coming in and out of intel_idle frequently, the lock contention on the tick_broadcast_lock can become significant. To reduce contention, the lock is put into its own cacheline and all the cpumask_var_t variables are put into the __read_mostly section. Running the SP benchmark of the NAS Parallel Benchmarks on a 4-socket 16-core 32-thread Nehalam system, the performance number improved from 3353.94 Mop/s to 3469.31 Mop/s when this patch was applied on a 4.9.6 kernel. This is a 3.4% improvement. Signed-off-by: Waiman Long <longman@redhat.com> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1485799063-20857-1-git-send-email-longman@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
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| .. | ||
| alarmtimer.c | ||
| clockevents.c | ||
| clocksource.c | ||
| hrtimer.c | ||
| itimer.c | ||
| jiffies.c | ||
| Kconfig | ||
| Makefile | ||
| ntp.c | ||
| ntp_internal.h | ||
| posix-clock.c | ||
| posix-cpu-timers.c | ||
| posix-stubs.c | ||
| posix-timers.c | ||
| sched_clock.c | ||
| test_udelay.c | ||
| tick-broadcast-hrtimer.c | ||
| tick-broadcast.c | ||
| tick-common.c | ||
| tick-internal.h | ||
| tick-oneshot.c | ||
| tick-sched.c | ||
| tick-sched.h | ||
| time.c | ||
| timeconst.bc | ||
| timeconv.c | ||
| timecounter.c | ||
| timekeeping.c | ||
| timekeeping.h | ||
| timekeeping_debug.c | ||
| timekeeping_internal.h | ||
| timer.c | ||
| timer_list.c | ||
| timer_stats.c | ||