[PATCH] per-task-delay-accounting: taskstats interface

Create a "taskstats" interface based on generic netlink (NETLINK_GENERIC
family), for getting statistics of tasks and thread groups during their
lifetime and when they exit.  The interface is intended for use by multiple
accounting packages though it is being created in the context of delay
accounting.

This patch creates the interface without populating the fields of the data
that is sent to the user in response to a command or upon the exit of a task.
Each accounting package interested in using taskstats has to provide an
additional patch to add its stats to the common structure.

[akpm@osdl.org: cleanups, Kconfig fix]
Signed-off-by: Shailabh Nagar <nagar@us.ibm.com>
Signed-off-by: Balbir Singh <balbir@in.ibm.com>
Cc: Jes Sorensen <jes@sgi.com>
Cc: Peter Chubb <peterc@gelato.unsw.edu.au>
Cc: Erich Focht <efocht@ess.nec.de>
Cc: Levent Serinol <lserinol@gmail.com>
Cc: Jay Lan <jlan@engr.sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index 3c2cf91defa7..9852ed8c2988 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -25,6 +25,7 @@
 #include <linux/mount.h>
 #include <linux/proc_fs.h>
 #include <linux/mempolicy.h>
+#include <linux/taskstats_kern.h>
 #include <linux/delayacct.h>
 #include <linux/cpuset.h>
 #include <linux/syscalls.h>
@@ -844,6 +845,7 @@ static void exit_notify(struct task_struct *tsk)
 fastcall NORET_TYPE void do_exit(long code)
 {
         struct task_struct *tsk = current;
+        struct taskstats *tidstats, *tgidstats;
         int group_dead;
 
         profile_task_exit(tsk);
@@ -882,6 +884,8 @@ fastcall NORET_TYPE void do_exit(long code)
                                 current->comm, current->pid,
                                 preempt_count());
 
+        taskstats_exit_alloc(&tidstats, &tgidstats);
+
         acct_update_integrals(tsk);
         if (tsk->mm) {
                 update_hiwater_rss(tsk->mm);
@@ -901,7 +905,10 @@ fastcall NORET_TYPE void do_exit(long code)
 #endif
         if (unlikely(tsk->audit_context))
                 audit_free(tsk);
+        taskstats_exit_send(tsk, tidstats, tgidstats);
+        taskstats_exit_free(tidstats, tgidstats);
         delayacct_tsk_exit(tsk);
+
         exit_mm(tsk);
 
         if (group_dead)