From: Fawzi Mohamed <fawzi@gmx.ch>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@elte.hu>,
Thomas Dargel <td@chemie.hu-berlin.de>,
Hillf Danton <dhillf@gmail.com>
Subject: [PATCH] fix oops in updating thread cputime and task time
Date: Fri, 16 Mar 2012 17:29:09 +0100 [thread overview]
Message-ID: <A4012A3B-7FF6-4ED8-8E00-51661D11CF4C@gmx.ch> (raw)
We have a machine with a (back ported) fix working without problems since a few days.
We don´t consider it
tested-by: Thomas Dargel <td@no-spam.hu-berlin.de>
because last time it did need 19 days of computation to happen, but it should be fixed.
Fawzi and Thomas.
>From fa4dccbaabaa1e08f3ca1835cc1b40e34a87fcdb Mon Sep 17 00:00:00 2001
From: Fawzi Mohamed <fawzi@gmx.ch>
Date: Mon, 12 Mar 2012 23:10:57 +0100
Subject: [PATCH] fix oops in updating thread cputime and task time
use div64_u64 instead of do_div to divide cputime_t with each other
because if cputime_t was u64 it would crash when overflowing u32.
KERNEL: ./vmlinux-2.6.32.54-0.3-default.gz
DEBUGINFO: .//vmlinux-2.6.32.54-0.3-default.debug
DUMPFILE: ./vmcore
CPUS: 24
DATE: Mon Mar 5 00:58:10 2012
UPTIME: 19 days, 11:01:56
LOAD AVERAGE: 0.74, 0.42, 0.40
TASKS: 731
NODENAME: node65
RELEASE: 2.6.32.54-0.3-default
VERSION: #1 SMP 2012-01-27 17:38:56 +0100
MACHINE: x86_64 (3067 Mhz)
MEMORY: 96 GB
PANIC: ""
PID: 11234
COMMAND: "ricc2_smp"
TASK: ffff881813de2240 [THREAD_INFO: ffff8818153c2000]
CPU: 8
STATE: TASK_RUNNING (PANIC)
crash> bt
PID: 11234 TASK: ffff881813de2240 CPU: 8 COMMAND: "ricc2_smp"
RIP: 00007f5e4f418617 RSP: 00007f5e4dd3ebd0 RFLAGS: 00000202
RAX: 0000000000000062 RBX: ffffffff81002f7b RCX: 0000000000000179
RDX: 00007f5e4dd3edb4 RSI: 00007f5e4dd3ec70 RDI: 0000000000000000
RBP: 00007f5e4dd3ecf0 R8: 0000000000000001 R9: 00007f5e4dd3edc4
R10: 0000000000000001 R11: 0000000000000246 R12: ffffffff8105eb81
R13: 00007f5e4dd3ed30 R14: 00007f5e4dd3f2f0 R15: 0000000000000000
ORIG_RAX: 0000000000000062 CS: 0033 SS: 002b
Basically the same problem was found earlier in kernel vmlinux-2.6.32.12-0.7-default.gz.
Signed-off-by: Fawzi Mohamed <fawzi@gmx.ch>
Signed-off-by: Thomas Dargel <td@no-spam.hu-berlin.de>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
---
kernel/sched/core.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index b342f57..f2cc092 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2934,7 +2934,7 @@ void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
u64 temp = (__force u64) rtime;
temp *= (__force u64) utime;
- do_div(temp, (__force u32) total);
+ temp = div64_u64(temp, total);
utime = (__force cputime_t) temp;
} else
utime = rtime;
@@ -2967,7 +2967,7 @@ void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
u64 temp = (__force u64) rtime;
temp *= (__force u64) cputime.utime;
- do_div(temp, (__force u32) total);
+ temp = div64_u64(temp, total);
utime = (__force cputime_t) temp;
} else
utime = rtime;
--
1.7.0.4
next reply other threads:[~2012-03-16 16:29 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-16 16:29 Fawzi Mohamed [this message]
2012-04-21 7:23 ` [PATCH] fix oops in updating thread cputime and task time Fawzi Mohamed
2012-04-25 12:10 ` Peter Zijlstra
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