Messages in this thread Patch in this message | | | Subject | [patch] Re: [regression bisect -next] BUG: using smp_processor_id() in preemptible [00000000] code: rmmod | From | Mike Galbraith <> | Date | Thu, 29 Oct 2009 09:39:12 +0100 |
| |
On Wed, 2009-10-28 at 22:42 -0400, Eric Paris wrote: > I get a slew of these on boot.
Ouch. This fix it up for you?
sched: protect task_hot() buddy check.
Eric Paris reported that commit f685ceacab07d3f6c236f04803e2f2f0dbcc5afb causes boot time PREEMPT_DEBUG complaints.
[ 4.590699] BUG: using smp_processor_id() in preemptible [00000000] code: rmmod/1314 [ 4.593043] caller is task_hot+0x86/0xd0 [ 4.593872] Pid: 1314, comm: rmmod Tainted: G W 2.6.32-rc3-fanotify #127 [ 4.595443] Call Trace: [ 4.596177] [<ffffffff812ad35b>] debug_smp_processor_id+0x11b/0x120 [ 4.597337] [<ffffffff81051d66>] task_hot+0x86/0xd0 [ 4.598320] [<ffffffff81066275>] set_task_cpu+0x115/0x270 [ 4.599368] [<ffffffff810985ab>] kthread_bind+0x6b/0x100 [ 4.600354] [<ffffffff810914f0>] start_workqueue_thread+0x30/0x60 [ 4.601545] [<ffffffff810941dd>] __create_workqueue_key+0x18d/0x2f0 [ 4.602526] [<ffffffff810d9bee>] stop_machine_create+0x4e/0xd0 [ 4.603811] [<ffffffff810c5818>] sys_delete_module+0x98/0x250 [ 4.604922] [<ffffffff810e2505>] ? audit_syscall_entry+0x205/0x290 [ 4.606202] [<ffffffff81013202>] system_call_fastpath+0x16/0x1b
Don't use this_rq() when preemptible.
Signed-off-by: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Reported-by: Eric Paris <eparis@redhat.com> LKML-Reference: <new-submission>
diff --git a/kernel/sched.c b/kernel/sched.c index 91ffb01..21f52c4 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2008,7 +2008,8 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) /* * Buddy candidates are cache hot: */ - if (sched_feat(CACHE_HOT_BUDDY) && this_rq()->nr_running && + if (sched_feat(CACHE_HOT_BUDDY) && + (preempt_count() ? this_rq()->nr_running : 1) && (&p->se == cfs_rq_of(&p->se)->next || &p->se == cfs_rq_of(&p->se)->last)) return 1;
| |