Currently, vmstat can calculate specific vm event with all_vm_events() however it calculates all vm events at a time. This patch introduces a new function to calculate only single event at a time.
Signed-off-by: Ebru Akagunduz <ebru.akagun...@gmail.com> Suggested-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com> Acked-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com> Reviewed-by: Rik van Riel <r...@redhat.com> Acked-by: Vlastimil Babka <vba...@suse.cz> Acked-by: Christoph Lameter <c...@linux.com> --- Changes in v2: - this patch newly created in this version - create sum event function to calculate particular vm event (Kirill A. Shutemov) Changes in v3: - add dummy definition of sum_vm_event when CONFIG_VM_EVENTS is not set (Kirill A. Shutemov) Changes in v4: - add Suggested-by tag (Vlastimil Babka) Changes in v5: - CC'ed Christoph Lameter <c...@linux.com> (Andrew Morton) Changes in v6: - Fix commit log (Christoph Lameter) include/linux/vmstat.h | 6 ++++++ mm/vmstat.c | 12 ++++++++++++ 2 files changed, 18 insertions(+) diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h index 02fce41..723be2c 100644 --- a/include/linux/vmstat.h +++ b/include/linux/vmstat.h @@ -53,6 +53,8 @@ static inline void count_vm_events(enum vm_event_item item, long delta) extern void all_vm_events(unsigned long *); +extern unsigned long sum_vm_event(enum vm_event_item item); + extern void vm_events_fold_cpu(int cpu); #else @@ -73,6 +75,10 @@ static inline void __count_vm_events(enum vm_event_item item, long delta) static inline void all_vm_events(unsigned long *ret) { } +static inline unsigned long sum_vm_event(enum vm_event_item item) +{ + return 0; +} static inline void vm_events_fold_cpu(int cpu) { } diff --git a/mm/vmstat.c b/mm/vmstat.c index 070fd90..d6b6c03 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -34,6 +34,18 @@ DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}}; EXPORT_PER_CPU_SYMBOL(vm_event_states); +unsigned long sum_vm_event(enum vm_event_item item) +{ + int cpu; + unsigned long ret = 0; + + get_online_cpus(); + for_each_online_cpu(cpu) + ret += per_cpu(vm_event_states, cpu).event[item]; + put_online_cpus(); + return ret; +} + static void sum_vm_events(unsigned long *ret) { int cpu; -- 1.9.1