diff options
| author | Ingo Molnar <mingo@elte.hu> | 2009-08-03 09:31:54 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-08-03 09:56:52 +0200 |
| commit | 47cab6a722d44c71c4f8224017ef548522243cf4 (patch) | |
| tree | 477bbe67a203d9704792d6ce46a9f1199587ddfe /drivers/char/sysrq.c | |
| parent | c1dc0b9c0c8979ce4d411caadff5c0d79dee58bc (diff) | |
debug lockups: Improve lockup detection, fix generic arch fallback
As Andrew noted, my previous patch ("debug lockups: Improve lockup
detection") broke/removed SysRq-L support from architecture that do
not provide a __trigger_all_cpu_backtrace implementation.
Restore a fallback path and clean up the SysRq-L machinery a bit:
- Rename the arch method to arch_trigger_all_cpu_backtrace()
- Simplify the define
- Document the method a bit - in the hope of more architectures
adding support for it.
[ The patch touches Sparc code for the rename. ]
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "David S. Miller" <davem@davemloft.net>
LKML-Reference: <20090802140809.7ec4bb6b.akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'drivers/char/sysrq.c')
| -rw-r--r-- | drivers/char/sysrq.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/drivers/char/sysrq.c b/drivers/char/sysrq.c index 165f307f30e..50eecfe1d72 100644 --- a/drivers/char/sysrq.c +++ b/drivers/char/sysrq.c @@ -223,7 +223,20 @@ static DECLARE_WORK(sysrq_showallcpus, sysrq_showregs_othercpus); static void sysrq_handle_showallcpus(int key, struct tty_struct *tty) { - trigger_all_cpu_backtrace(); + /* + * Fall back to the workqueue based printing if the + * backtrace printing did not succeed or the + * architecture has no support for it: + */ + if (!trigger_all_cpu_backtrace()) { + struct pt_regs *regs = get_irq_regs(); + + if (regs) { + printk(KERN_INFO "CPU%d:\n", smp_processor_id()); + show_regs(regs); + } + schedule_work(&sysrq_showallcpus); + } } static struct sysrq_key_op sysrq_showallcpus_op = { |