From f5f302e21257ebb0c074bbafc37606c26d28cc3d Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Fri, 12 Dec 2014 16:56:10 -0800 Subject: [PATCH] mm,vmacache: count number of system-wide flushes These flushes deal with sequence number overflows, such as for long lived threads. These are rare, but interesting from a debugging PoV. As such, display the number of flushes when vmacache debugging is enabled. Signed-off-by: Davidlohr Bueso Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/vm_event_item.h | 1 + mm/vmacache.c | 2 ++ mm/vmstat.c | 1 + 3 files changed, 4 insertions(+) diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h index 730334cdf037..9246d32dc973 100644 --- a/include/linux/vm_event_item.h +++ b/include/linux/vm_event_item.h @@ -90,6 +90,7 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, #ifdef CONFIG_DEBUG_VM_VMACACHE VMACACHE_FIND_CALLS, VMACACHE_FIND_HITS, + VMACACHE_FULL_FLUSHES, #endif NR_VM_EVENT_ITEMS }; diff --git a/mm/vmacache.c b/mm/vmacache.c index 9f25af825dec..b6e3662fe339 100644 --- a/mm/vmacache.c +++ b/mm/vmacache.c @@ -17,6 +17,8 @@ void vmacache_flush_all(struct mm_struct *mm) { struct task_struct *g, *p; + count_vm_vmacache_event(VMACACHE_FULL_FLUSHES); + /* * Single threaded tasks need not iterate the entire * list of process. We can avoid the flushing as well diff --git a/mm/vmstat.c b/mm/vmstat.c index b090e9e3d626..1284f89fca08 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -900,6 +900,7 @@ const char * const vmstat_text[] = { #ifdef CONFIG_DEBUG_VM_VMACACHE "vmacache_find_calls", "vmacache_find_hits", + "vmacache_full_flushes", #endif #endif /* CONFIG_VM_EVENTS_COUNTERS */ };