diff options
author | Jiri Olsa <jolsa@redhat.com> | 2016-03-01 20:03:52 +0100 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2016-03-08 12:18:32 +0100 |
commit | e72daf3f4d764c47fb71c9bdc7f9c54a503825b1 (patch) | |
tree | 0ba39e046d71722ee9247bf3d7de095ac5ed9e93 /arch/x86/events/intel | |
parent | 927a5570855836e5d5859a80ce7e91e963545e8f (diff) |
perf/x86/intel: Use PAGE_SIZE for PEBS buffer size on Core2
Using PAGE_SIZE buffers makes the WRMSR to PERF_GLOBAL_CTRL in
intel_pmu_enable_all() mysteriously hang on Core2. As a workaround, we
don't do this.
The hard lockup is easily triggered by running 'perf test attr'
repeatedly. Most of the time it gets stuck on sample session with
small periods.
# perf test attr -vv
14: struct perf_event_attr setup :
--- start ---
...
'PERF_TEST_ATTR=/tmp/tmpuEKz3B /usr/bin/perf record -o /tmp/tmpuEKz3B/perf.data -c 123 kill >/dev/null 2>&1' ret 1
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: <stable@vger.kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20160301190352.GA8355@krava.redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/events/intel')
-rw-r--r-- | arch/x86/events/intel/ds.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c index c8a243d6fc82..22ece02d01b6 100644 --- a/arch/x86/events/intel/ds.c +++ b/arch/x86/events/intel/ds.c @@ -269,7 +269,7 @@ static int alloc_pebs_buffer(int cpu) if (!x86_pmu.pebs) return 0; - buffer = kzalloc_node(PEBS_BUFFER_SIZE, GFP_KERNEL, node); + buffer = kzalloc_node(x86_pmu.pebs_buffer_size, GFP_KERNEL, node); if (unlikely(!buffer)) return -ENOMEM; @@ -286,7 +286,7 @@ static int alloc_pebs_buffer(int cpu) per_cpu(insn_buffer, cpu) = ibuffer; } - max = PEBS_BUFFER_SIZE / x86_pmu.pebs_record_size; + max = x86_pmu.pebs_buffer_size / x86_pmu.pebs_record_size; ds->pebs_buffer_base = (u64)(unsigned long)buffer; ds->pebs_index = ds->pebs_buffer_base; @@ -1319,6 +1319,7 @@ void __init intel_ds_init(void) x86_pmu.bts = boot_cpu_has(X86_FEATURE_BTS); x86_pmu.pebs = boot_cpu_has(X86_FEATURE_PEBS); + x86_pmu.pebs_buffer_size = PEBS_BUFFER_SIZE; if (x86_pmu.pebs) { char pebs_type = x86_pmu.intel_cap.pebs_trap ? '+' : '-'; int format = x86_pmu.intel_cap.pebs_format; @@ -1327,6 +1328,14 @@ void __init intel_ds_init(void) case 0: pr_cont("PEBS fmt0%c, ", pebs_type); x86_pmu.pebs_record_size = sizeof(struct pebs_record_core); + /* + * Using >PAGE_SIZE buffers makes the WRMSR to + * PERF_GLOBAL_CTRL in intel_pmu_enable_all() + * mysteriously hang on Core2. + * + * As a workaround, we don't do this. + */ + x86_pmu.pebs_buffer_size = PAGE_SIZE; x86_pmu.drain_pebs = intel_pmu_drain_pebs_core; break; |