From b663a79c191508f27cd885224b592a878c0ba0f6 Mon Sep 17 00:00:00 2001 From: Maxim Uvarov Date: Sun, 15 Jul 2007 23:40:48 -0700 Subject: taskstats: add context-switch counters Make available to the user the following task and process performance statistics: * Involuntary Context Switches (task_struct->nivcsw) * Voluntary Context Switches (task_struct->nvcsw) Statistics information is available from: 1. taskstats interface (Documentation/accounting/) 2. /proc/PID/status (task only). This data is useful for detecting hyperactivity patterns between processes. [akpm@linux-foundation.org: cleanup] Signed-off-by: Maxim Uvarov Cc: Shailabh Nagar Cc: Balbir Singh Cc: Jay Lan Cc: Jonathan Lim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/array.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'fs') diff --git a/fs/proc/array.c b/fs/proc/array.c index 680c913..9cbab7e 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -289,6 +289,15 @@ static inline char *task_cap(struct task_struct *p, char *buffer) cap_t(p->cap_effective)); } +static inline char *task_context_switch_counts(struct task_struct *p, + char *buffer) +{ + return buffer + sprintf(buffer, "voluntary_ctxt_switches:\t%lu\n" + "nonvoluntary_ctxt_switches:\t%lu\n", + p->nvcsw, + p->nivcsw); +} + int proc_pid_status(struct task_struct *task, char * buffer) { char * orig = buffer; @@ -307,6 +316,7 @@ int proc_pid_status(struct task_struct *task, char * buffer) #if defined(CONFIG_S390) buffer = task_show_regs(task, buffer); #endif + buffer = task_context_switch_counts(task, buffer); return buffer - orig; } -- cgit v1.1