per-thread rusage

[William Lee Irwin III <wli@holomorphy.com>]

It is not now possible for a thread to retrieve its own rusage in
isolation. Its rusage is nowhere exposed without being intermixed with
that of its sibling threads. This patch adds support for an
RUSAGE_THREAD who argument that returns rusage for only the desired
thread.

Untested.


-- wli


Index: anon/include/linux/resource.h
===================================================================
--- anon.orig/include/linux/resource.h	2007-04-04 09:57:41.239118534 -0700
+++ anon/include/linux/resource.h	2007-04-04 09:57:59.840178548 -0700
@@ -18,7 +18,8 @@
  */
 #define	RUSAGE_SELF	0
 #define	RUSAGE_CHILDREN	(-1)
-#define RUSAGE_BOTH	(-2)		/* sys_wait4() uses this */
+#define RUSAGE_THREAD	(-2)
+#define RUSAGE_BOTH	(-3)		/* sys_wait4() uses this */
 
 struct	rusage {
 	struct timeval ru_utime;	/* user time used */
Index: anon/kernel/sys.c
===================================================================
--- anon.orig/kernel/sys.c	2007-04-04 09:58:03.964413575 -0700
+++ anon/kernel/sys.c	2007-04-04 10:11:22.417914846 -0700
@@ -2013,6 +2013,14 @@
 	}
 
 	switch (who) {
+		case RUSAGE_THREAD:
+			utime = p->utime;
+			stime = p->stime;
+			r->ru_nvcsw = p->nvcsw;
+			r->ru_nivcsw = p->nivcsw;
+			r->ru_minflt = p->min_flt;
+			r->ru_majflt = p->maj_flt;
+			break;
 		case RUSAGE_BOTH:
 		case RUSAGE_CHILDREN:
 			utime = p->signal->cutime;
@@ -2064,7 +2072,8 @@
 
 asmlinkage long sys_getrusage(int who, struct rusage __user *ru)
 {
-	if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
+	if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
+						who != RUSAGE_THREAD)
 		return -EINVAL;
 	return getrusage(current, who, ru);
 }