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perf_counter: fix print debug irq disable

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inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
bash/15802 [HC0[0]:SC0[0]:HE1:SE1] takes:
 (sysrq_key_table_lock){?.....},

Don't unconditionally enable interrupts in the perf_counter_print_debug()
path.

[ Impact: fix potential deadlock pointed out by lockdep ]

LKML-Reference: <new-submission>
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
This commit is contained in:
Peter Zijlstra 2009-05-13 08:12:51 +02:00 committed by Ingo Molnar
parent e758a33d6f
commit 5bb9efe33e
1 changed files with 3 additions and 2 deletions
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5
arch/x86/kernel/cpu/perf_counter.c
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@ -621,12 +621,13 @@ void perf_counter_print_debug(void)
{
u64 ctrl, status, overflow, pmc_ctrl, pmc_count, prev_left, fixed;
struct cpu_hw_counters *cpuc;
unsigned long flags;
int cpu, idx;
if (!x86_pmu.num_counters)
return;
local_irq_disable();
local_irq_save(flags);
cpu = smp_processor_id();
cpuc = &per_cpu(cpu_hw_counters, cpu);
@ -664,7 +665,7 @@ void perf_counter_print_debug(void)
pr_info("CPU#%d: fixed-PMC%d count: %016llx\n",
cpu, idx, pmc_count);
}
local_irq_enable();
local_irq_restore(flags);
}
static void x86_pmu_disable(struct perf_counter *counter)