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authorPeter Zijlstra <peterz@infradead.org>2009-09-23 09:03:37 (GMT)
committerIngo Molnar <mingo@elte.hu>2009-09-23 09:25:56 (GMT)
commit7d42896628202a551ad1107697cd215dc5fca099 (patch)
tree9db9079ab5898daf4ae7be82b5a170612659d9ed /arch/x86/kernel/cpu
parenta6f10a2f5d8c2738b3ac05974bdbea3b68a2aecd (diff)
downloadlinux-7d42896628202a551ad1107697cd215dc5fca099.tar.xz
perf_event, x86: Fix 'perf sched record' crashing the machine
Chris Malley reported that 'perf sched record' sometimes crashes his box with: [ 389.272175] BUG: unable to handle kernel paging request at ffffb300 [ 389.272294] IP: [<c011b0bd>] default_send_IPI_self+0x1d/0x50 [ 389.272366] *pde = 0073f067 *pte = 00000000 [ 389.274708] Call Trace: [ 389.274752] [<c010e3b4>] ? set_perf_event_pending+0x14/0x20 [ 389.274801] [<c01b9751>] ? perf_output_unlock+0x121/0x1a0 [ 389.274848] [<c01b981a>] ? perf_output_end+0x4a/0x70 [ 389.274893] [<c01ba690>] ? __perf_event_overflow+0x240/0x2f0 [ 389.274942] [<c030963e>] ? atomic64_cmpxchg+0x1e/0x30 [ 389.274988] [<c01ba8f4>] ? perf_swevent_ctx_event+0x1b4/0x1c0 [ 389.275035] [<c01ba773>] ? perf_swevent_ctx_event+0x33/0x1c0 [ 389.275081] [<c01ba9a7>] ? do_perf_sw_event+0xa7/0x160 [ 389.275127] [<c01baae2>] ? perf_tp_event+0x82/0xa0 [ 389.275174] [<c012e9c6>] ? ftrace_profile_sched_stat_runtime+0xe6/0x120 [ 389.275224] [<c012e8e0>] ? ftrace_profile_sched_stat_runtime+0x0/0x120 [ 389.275273] [<c013c85a>] ? update_curr+0x18a/0x230 [ 389.275318] [<c013cdc5>] ? put_prev_task_fair+0x155/0x160 [ 389.275366] [<c01618b5>] ? sched_clock_cpu+0xd5/0x110 [ 389.275413] [<c04e7525>] ? _spin_lock_irq+0x45/0x50 [ 389.275458] [<c04e424e>] ? schedule+0x20e/0xb10 The problem is that the box has no lapic enabled: [ 0.042445] Local APIC not detected. Using dummy APIC emulation. The below seems like the best fix. We disabled all lapic bits, except the self-IPI-resend logic. Reported-by: Chris Malley <mail@chrismalley.co.uk> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <7863dc4c0909221409v7893bfd3o4b590d5951a233ba@mail.gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/cpu')
-rw-r--r--arch/x86/kernel/cpu/perf_event.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index a3c7adb..b5801c3 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1790,6 +1790,9 @@ void smp_perf_pending_interrupt(struct pt_regs *regs)
void set_perf_event_pending(void)
{
#ifdef CONFIG_X86_LOCAL_APIC
+ if (!x86_pmu.apic || !x86_pmu_initialized())
+ return;
+
apic->send_IPI_self(LOCAL_PENDING_VECTOR);
#endif
}