Messages in this thread Patch in this message | | | From | Feng Tang <> | Subject | [PATCH 2/3] mm/util.c: make vm_memory_committed() more accurate | Date | Fri, 8 May 2020 15:25:16 +0800 |
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percpu_counter_sum_positive() will provide more accurate info.
Its time cost is about 800 nanoseconds on a 2C/4T platform and 2~3 microseconds on a 2S/36C/72T server in normal case, and in worst case where vm_committed_as's spinlock is under severe contention, it costs 30~40 microseconds for the 2S/36C/72T sever, which should be fine for its two users: /proc/meminfo and HV ballon driver's status trace per second.
Signed-off-by: Feng Tang <feng.tang@intel.com> --- mm/util.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/util.c b/mm/util.c index 988d11e..3de78e9 100644 --- a/mm/util.c +++ b/mm/util.c @@ -774,7 +774,7 @@ struct percpu_counter vm_committed_as ____cacheline_aligned_in_smp; */ unsigned long vm_memory_committed(void) { - return percpu_counter_read_positive(&vm_committed_as); + return percpu_counter_sum_positive(&vm_committed_as); } EXPORT_SYMBOL_GPL(vm_memory_committed); -- 2.7.4
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