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authorLinus Torvalds <torvalds@linux-foundation.org>2018-01-28 22:48:25 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-01-28 22:48:25 +0300
commit39e383626caffd2b5f4407710157b32172898869 (patch)
tree978199e59b072fd07ca855dd395d4db681a18a18 /arch/x86
parent8c76e31a6af1f27f7ccd381757adcae2984eac91 (diff)
parentefe951d3de9141626a494bcb1efb0650eaef6491 (diff)
downloadlinux-39e383626caffd2b5f4407710157b32172898869.tar.xz
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner: "Four patches which all address lock inversions and deadlocks in the perf core code and the Intel debug store" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86: Fix perf,x86,cpuhp deadlock perf/core: Fix ctx::mutex deadlock perf/core: Fix another perf,trace,cpuhp lock inversion perf/core: Fix lock inversion between perf,trace,cpuhp
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/events/intel/ds.c33
1 files changed, 18 insertions, 15 deletions
diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index 8156e47da7ba..18c25ab28557 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -372,10 +372,9 @@ static int alloc_pebs_buffer(int cpu)
static void release_pebs_buffer(int cpu)
{
struct cpu_hw_events *hwev = per_cpu_ptr(&cpu_hw_events, cpu);
- struct debug_store *ds = hwev->ds;
void *cea;
- if (!ds || !x86_pmu.pebs)
+ if (!x86_pmu.pebs)
return;
kfree(per_cpu(insn_buffer, cpu));
@@ -384,7 +383,6 @@ static void release_pebs_buffer(int cpu)
/* Clear the fixmap */
cea = &get_cpu_entry_area(cpu)->cpu_debug_buffers.pebs_buffer;
ds_clear_cea(cea, x86_pmu.pebs_buffer_size);
- ds->pebs_buffer_base = 0;
dsfree_pages(hwev->ds_pebs_vaddr, x86_pmu.pebs_buffer_size);
hwev->ds_pebs_vaddr = NULL;
}
@@ -419,16 +417,14 @@ static int alloc_bts_buffer(int cpu)
static void release_bts_buffer(int cpu)
{
struct cpu_hw_events *hwev = per_cpu_ptr(&cpu_hw_events, cpu);
- struct debug_store *ds = hwev->ds;
void *cea;
- if (!ds || !x86_pmu.bts)
+ if (!x86_pmu.bts)
return;
/* Clear the fixmap */
cea = &get_cpu_entry_area(cpu)->cpu_debug_buffers.bts_buffer;
ds_clear_cea(cea, BTS_BUFFER_SIZE);
- ds->bts_buffer_base = 0;
dsfree_pages(hwev->ds_bts_vaddr, BTS_BUFFER_SIZE);
hwev->ds_bts_vaddr = NULL;
}
@@ -454,16 +450,22 @@ void release_ds_buffers(void)
if (!x86_pmu.bts && !x86_pmu.pebs)
return;
- get_online_cpus();
- for_each_online_cpu(cpu)
+ for_each_possible_cpu(cpu)
+ release_ds_buffer(cpu);
+
+ for_each_possible_cpu(cpu) {
+ /*
+ * Again, ignore errors from offline CPUs, they will no longer
+ * observe cpu_hw_events.ds and not program the DS_AREA when
+ * they come up.
+ */
fini_debug_store_on_cpu(cpu);
+ }
for_each_possible_cpu(cpu) {
release_pebs_buffer(cpu);
release_bts_buffer(cpu);
- release_ds_buffer(cpu);
}
- put_online_cpus();
}
void reserve_ds_buffers(void)
@@ -483,8 +485,6 @@ void reserve_ds_buffers(void)
if (!x86_pmu.pebs)
pebs_err = 1;
- get_online_cpus();
-
for_each_possible_cpu(cpu) {
if (alloc_ds_buffer(cpu)) {
bts_err = 1;
@@ -521,11 +521,14 @@ void reserve_ds_buffers(void)
if (x86_pmu.pebs && !pebs_err)
x86_pmu.pebs_active = 1;
- for_each_online_cpu(cpu)
+ for_each_possible_cpu(cpu) {
+ /*
+ * Ignores wrmsr_on_cpu() errors for offline CPUs they
+ * will get this call through intel_pmu_cpu_starting().
+ */
init_debug_store_on_cpu(cpu);
+ }
}
-
- put_online_cpus();
}
/*