Fill in ru_maxrss by, for RUSAGE_BOTH or RUSAGE_CHILDREN, walking the
list of children and summing the hiwater_rss for each. For RUSAGE_BOTH
or RUSAGE_SELF also include the hiwater_rss for the calling process.
diff --git a/kernel/sys.c b/kernel/sys.c
index 449b81b..71b2850 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -2101,6 +2101,19 @@ static void k_getrusage(struct task_stru
r->ru_inblock = p->signal->cinblock;
r->ru_oublock = p->signal->coublock;
+ read_lock(&tasklist_lock);
+ list_for_each(_p, &p->children) {
+ struct task_struct *mp;
+
+ mp = list_entry(_p, struct task_struct,
sibling);
+ mm = get_task_mm(mp);
+ hiwater_rss = get_mm_rss(mm);
+ if (hiwater_rss < mm->hiwater_rss)
+ hiwater_rss = mm->hiwater_rss;
+ r->ru_maxrss += hiwater_rss;
+ }
+ read_unlock(&tasklist_lock);
+
if (who == RUSAGE_CHILDREN)
break;
@@ -2125,6 +2138,11 @@ static void k_getrusage(struct task_stru
r->ru_oublock += task_io_get_oublock(t);
t = next_thread(t);
} while (t != p);
+ mm = get_task_mm(p);
+ hiwater_rss = get_mm_rss(mm);
+ if (hiwater_rss < mm->hiwater_rss)
+ hiwater_rss = mm->hiwater_rss;
+ r->ru_maxrss += hiwater_rss;
break;
default:
---
Like a number of other folks, we recently had a need for a non-/proc way
of getting the RSS of a process and happened on getrusage(). Unlike the
rest, though, we fixed the system call to do what we want.
The code itself was lifted from task_mem() in proc/task_mmu.c. The only
questionable bit is where it does the read_lock() of the tasklist_lock;
although it seems safe enough, I would appreciate if those more
knowledgeable about that locking vet it (briefly) for safety.
Signed-off-by: Frank Mayhar <[EMAIL PROTECTED]>
--
Frank Mayhar <[EMAIL PROTECTED]>
Google, Inc.
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