Messages in this thread | | | Date | Mon, 30 Dec 2013 17:06:02 +0800 | From | Weng Meiling <> | Subject | Re: [PATCH] oprofile: check whether oprofile perf enabled in op_overflow_handler() |
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Hi Robert, What do you think about this patch?
On 2013/12/20 15:49, Weng Meiling wrote: > > From: Weng Meiling <wengmeiling.weng@huawei.com> > > There is a situation event is triggered before oprofile_perf_start() finish. > Because the event is still not stored in per_cpu(perf_events, cpu)[event], > op_overflow_handler() will print the warning. During the time, if unregistered > event is triggered again, the cpu will print again. This may make cpu keeping > on printing and trigger softlockup. So check whether events register finished > in op_overflow_handler(). > > The problem was once triggered on kernel 2.6.34, the main information: > <3>BUG: soft lockup - CPU#0 stuck for 60005ms! [opcontrol:8673] > > Pid: 8673, comm: opcontrol > =====================SOFTLOCKUP INFO BEGIN======================= > [CPU#0] the task [opcontrol] is not waiting for a lock,maybe a delay or deadcricle! > <6>opcontrol R<c> running <c> 0 8673 7603 0x00000002 > locked: > bf0e1928 mutex 0 [<bf0de0d8>] oprofile_start+0x10/0x68 [oprofile] > bf0e1a24 mutex 0 [<bf0e07f0>] op_arm_start+0x10/0x48 [oprofile] > c0628020 &ctx->mutex 0 [<c00af85c>] perf_event_create_kernel_counter+0xa4/0x14c > [<c00362b8>] (unwind_backtrace+0x0/0x164) from [<c0031db4>] (show_stack+0x10/0x14) > [<c0031db4>] (show_stack+0x10/0x14) from [<c008d964>] (show_lock_info+0x9c/0x168) > [<c008d964>] (show_lock_info+0x9c/0x168) from [<c008dbf4>] (softlockup_tick+0x1c4/0x234) > [<c008dbf4>] (softlockup_tick+0x1c4/0x234) from [<c0066d58>] (update_process_times+0x2c/0x50) > [<c0066d58>] (update_process_times+0x2c/0x50) from [<c00811cc>] (tick_sched_timer+0x268/0x2c4) > [<c00811cc>] (tick_sched_timer+0x268/0x2c4) from [<c0077340>] (__run_hrtimer+0x158/0x25c) > [<c0077340>] (__run_hrtimer+0x158/0x25c) from [<c0077e08>] (hrtimer_interrupt+0x13c/0x2f8) > [<c0077e08>] (hrtimer_interrupt+0x13c/0x2f8) from [<c003f82c>] (timer64_timer_interrupt+0x20/0x2c) > [<c003f82c>] (timer64_timer_interrupt+0x20/0x2c) from [<c008e54c>] (handle_IRQ_event+0x144/0x2ec) > [<c008e54c>] (handle_IRQ_event+0x144/0x2ec) from [<c00900dc>] (handle_level_irq+0xc0/0x13c) > [<c00900dc>] (handle_level_irq+0xc0/0x13c) from [<c002b080>] (asm_do_IRQ+0x80/0xbc) > [<c002b080>] (asm_do_IRQ+0x80/0xbc) from [<c0274b8c>] (__irq_svc+0x4c/0xe4) > Exception stack(0xc4099db8 to 0xc4099e00) > 9da0: c0357538 00000000 > 9dc0: 00000000 c0380cc0 c4098000 00000202 00000028 c4098000 3fca9fbc c4098000 > 9de0: c0028b08 00000000 c4098000 c4099e00 c005eb50 c005e544 20000113 ffffffff > [<c0274b8c>] (__irq_svc+0x4c/0xe4) from [<c005e544>] (__do_softirq+0x64/0x25c) > [<c005e544>] (__do_softirq+0x64/0x25c) from [<c005eb50>] (irq_exit+0x48/0x5c) > [<c005eb50>] (irq_exit+0x48/0x5c) from [<c002b084>] (asm_do_IRQ+0x84/0xbc) > [<c002b084>] (asm_do_IRQ+0x84/0xbc) from [<c0274b8c>] (__irq_svc+0x4c/0xe4) > Exception stack(0xc4099e58 to 0xc4099ea0) > 9e40: c0628010 20000093 > 9e60: 00000001 00000000 00000000 60000013 c00aff24 cc4f6c00 00000001 c4098000 > 9e80: 00000000 00000000 00000000 c4099ea0 c0084fa0 c0084fa4 60000013 ffffffff > [<c0274b8c>] (__irq_svc+0x4c/0xe4) from [<c0084fa4>] (smp_call_function_single+0xc0/0x1d8) > [<c0084fa4>] (smp_call_function_single+0xc0/0x1d8) from [<c00af86c>] (perf_event_create_kernel_counter+0xb4/0x14c) > [<c00af86c>] (perf_event_create_kernel_counter+0xb4/0x14c) from [<bf0e0700>] (op_perf_start+0x54/0xf0 [oprofile]) > [<bf0e0700>] (op_perf_start+0x54/0xf0 [oprofile]) from [<bf0e0800>] (op_arm_start+0x20/0x48 [oprofile]) > [<bf0e0800>] (op_arm_start+0x20/0x48 [oprofile]) from [<bf0de100>] (oprofile_start+0x38/0x68 [oprofile]) > [<bf0de100>] (oprofile_start+0x38/0x68 [oprofile]) from [<bf0dfac0>] (enable_write+0x34/0x54 [oprofile]) > [<bf0dfac0>] (enable_write+0x34/0x54 [oprofile]) from [<c00e5368>] (vfs_write+0xa8/0x150) > [<c00e5368>] (vfs_write+0xa8/0x150) from [<c00e5698>] (sys_write+0x3c/0x100) > [<c00e5698>] (sys_write+0x3c/0x100) from [<c002c500>] (ret_fast_syscall+0x0/0x30) > =====================SOFTLOCKUP INFO END========================= > <0>Kernel panic - not syncing: softlockup: hung tasks > > Cc: <stable@vger.kernel.org> # 2.6.34+ > Signed-off-by: Weng Meiling <wengmeiling.weng@huawei.com> > --- > drivers/oprofile/oprofile_perf.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/oprofile/oprofile_perf.c b/drivers/oprofile/oprofile_perf.c > index d5b2732..a9e5761 100644 > --- a/drivers/oprofile/oprofile_perf.c > +++ b/drivers/oprofile/oprofile_perf.c > @@ -38,6 +38,9 @@ static void op_overflow_handler(struct perf_event *event, > int id; > u32 cpu = smp_processor_id(); > > + if (!oprofile_perf_enabled) > + return; > + > for (id = 0; id < num_counters; ++id) > if (per_cpu(perf_events, cpu)[id] == event) > break; >
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