On Mon, 7 Aug 2017 13:40:34 +0800 "Huang, Ying" <ying.huang@xxxxxxxxx> wrote: > From: Huang Ying <ying.huang@xxxxxxxxx> > > The statistics for total readahead pages and total readahead hits are > recorded and exported via the following sysfs interface. > > /sys/kernel/mm/swap/ra_hits > /sys/kernel/mm/swap/ra_total > > With them, the efficiency of the swap readahead could be measured, so > that the swap readahead algorithm and parameters could be tuned > accordingly. > > ... > > --- a/include/linux/vm_event_item.h > +++ b/include/linux/vm_event_item.h > @@ -106,6 +106,8 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, > VMACACHE_FIND_HITS, > VMACACHE_FULL_FLUSHES, > #endif > + SWAP_RA, > + SWAP_RA_HIT, > NR_VM_EVENT_ITEMS > }; swap_state.o isn't even compiled if CONFIG_SWAP=n so there doesn't seem much point in displaying these? --- a/include/linux/vm_event_item.h~mm-swap-add-swap-readahead-hit-statistics-fix +++ a/include/linux/vm_event_item.h @@ -106,8 +106,10 @@ enum vm_event_item { PGPGIN, PGPGOUT, PS VMACACHE_FIND_HITS, VMACACHE_FULL_FLUSHES, #endif +#ifdef CONFIG_SWAP SWAP_RA, SWAP_RA_HIT, +#endif NR_VM_EVENT_ITEMS }; --- a/mm/vmstat.c~mm-swap-add-swap-readahead-hit-statistics-fix +++ a/mm/vmstat.c @@ -1098,9 +1098,10 @@ const char * const vmstat_text[] = { "vmacache_find_hits", "vmacache_full_flushes", #endif - +#ifdef CONFIG_SWAP "swap_ra", "swap_ra_hit", +#endif #endif /* CONFIG_VM_EVENTS_COUNTERS */ }; #endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */ _ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>