From: Konstantin Khorenko <khore...@virtuozzo.com> Up to now "page_in" and "swap_in" in /proc/vz/latency has been provided in cpu cycles while other latencies are in nanoseconds there.
Let's make a single measure unit for all latencies, so provide swap_in and page_in in nanoseconds as well. Note: we left time accounting using direct rdtsc() with converting to ns afterwards. We understand there are some issues possible with correctness and using ktime_to_ns(ktime_get()) would be better (as it's done for other latencies), but switching to ktime_get() results in 2% performance loss on first memory access (pagefault + memory read), so decided not to slowdown fastpath and be aware of possible stats incorrectness. https://pmc.acronis.com/browse/VSTOR-16659 Signed-off-by: Konstantin Khorenko <khore...@virtuozzo.com> (cherry-picked from aedfe36c7fc590da6c0da3f68818d521fc90028e) Signed-off-by: Andrey Zhadchenko <andrey.zhadche...@virtuozzo.com> diff --git a/mm/memory.c b/mm/memory.c index 9ee4c80..f13349d 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -78,6 +78,7 @@ #include <asm/tlb.h> #include <asm/tlbflush.h> #include <asm/pgtable.h> +#include <asm/tsc.h> #include "internal.h" @@ -3019,6 +3020,8 @@ void unmap_mapping_range(struct address_space *mapping, } EXPORT_SYMBOL(unmap_mapping_range); +#define CLKS2NSEC(c) ((c) * 1000000 / tsc_khz) + /* * We enter with non-exclusive mmap_sem (to exclude vma changes, * but allow concurrent faults), and pte mapped but not yet locked. @@ -3229,7 +3232,8 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) pte_unmap_unlock(vmf->pte, vmf->ptl); out: local_irq_disable(); - KSTAT_LAT_PCPU_ADD(&kstat_glob.swap_in, get_cycles() - start); + KSTAT_LAT_PCPU_ADD(&kstat_glob.swap_in, + CLKS2NSEC(get_cycles() - start)); local_irq_enable(); return ret; @@ -3415,7 +3419,8 @@ static vm_fault_t __do_fault(struct vm_fault *vmf) VM_BUG_ON_PAGE(!PageLocked(vmf->page), vmf->page); local_irq_disable(); - KSTAT_LAT_PCPU_ADD(&kstat_glob.page_in, get_cycles() - start); + KSTAT_LAT_PCPU_ADD(&kstat_glob.page_in, + CLKS2NSEC(get_cycles() - start)); local_irq_enable(); return ret; -- 1.8.3.1 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
