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authorLinus Torvalds <torvalds@linux-foundation.org>2016-12-23 16:49:12 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-23 16:49:12 -0800
commit00198dab3b825ab264424a052beea5acb859754f (patch)
tree1afa5fc96a0447bc8049a9992e5d4d047f5f0b38 /arch
parent9004fda59577d439564d44d6d1db52d262fe3f99 (diff)
parent3705b97505bcbf6440f38119c0e7d6058f585b54 (diff)
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar: "On the kernel side there's two x86 PMU driver fixes and a uprobes fix, plus on the tooling side there's a number of fixes and some late updates" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) perf sched timehist: Fix invalid period calculation perf sched timehist: Remove hardcoded 'comm_width' check at print_summary perf sched timehist: Enlarge default 'comm_width' perf sched timehist: Honour 'comm_width' when aligning the headers perf/x86: Fix overlap counter scheduling bug perf/x86/pebs: Fix handling of PEBS buffer overflows samples/bpf: Move open_raw_sock to separate header samples/bpf: Remove perf_event_open() declaration samples/bpf: Be consistent with bpf_load_program bpf_insn parameter tools lib bpf: Add bpf_prog_{attach,detach} samples/bpf: Switch over to libbpf perf diff: Do not overwrite valid build id perf annotate: Don't throw error for zero length symbols perf bench futex: Fix lock-pi help string perf trace: Check if MAP_32BIT is defined (again) samples/bpf: Make perf_event_read() static uprobes: Fix uprobes on MIPS, allow for a cache flush after ixol breakpoint creation samples/bpf: Make samples more libbpf-centric tools lib bpf: Add flags to bpf_create_map() tools lib bpf: use __u32 from linux/types.h ...
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/events/intel/core.c30
-rw-r--r--arch/x86/events/intel/uncore_snbep.c2
2 files changed, 22 insertions, 10 deletions
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index cb8522290e6a..86138267b68a 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -2110,6 +2110,27 @@ again:
GLOBAL_STATUS_LBRS_FROZEN);
if (!status)
goto done;
+ /*
+ * In case multiple PEBS events are sampled at the same time,
+ * it is possible to have GLOBAL_STATUS bit 62 set indicating
+ * PEBS buffer overflow and also seeing at most 3 PEBS counters
+ * having their bits set in the status register. This is a sign
+ * that there was at least one PEBS record pending at the time
+ * of the PMU interrupt. PEBS counters must only be processed
+ * via the drain_pebs() calls and not via the regular sample
+ * processing loop coming after that the function, otherwise
+ * phony regular samples may be generated in the sampling buffer
+ * not marked with the EXACT tag. Another possibility is to have
+ * one PEBS event and at least one non-PEBS event whic hoverflows
+ * while PEBS has armed. In this case, bit 62 of GLOBAL_STATUS will
+ * not be set, yet the overflow status bit for the PEBS counter will
+ * be on Skylake.
+ *
+ * To avoid this problem, we systematically ignore the PEBS-enabled
+ * counters from the GLOBAL_STATUS mask and we always process PEBS
+ * events via drain_pebs().
+ */
+ status &= ~cpuc->pebs_enabled;
/*
* PEBS overflow sets bit 62 in the global status register
@@ -2117,15 +2138,6 @@ again:
if (__test_and_clear_bit(62, (unsigned long *)&status)) {
handled++;
x86_pmu.drain_pebs(regs);
- /*
- * There are cases where, even though, the PEBS ovfl bit is set
- * in GLOBAL_OVF_STATUS, the PEBS events may also have their
- * overflow bits set for their counters. We must clear them
- * here because they have been processed as exact samples in
- * the drain_pebs() routine. They must not be processed again
- * in the for_each_bit_set() loop for regular samples below.
- */
- status &= ~cpuc->pebs_enabled;
status &= x86_pmu.intel_ctrl | GLOBAL_STATUS_TRACE_TOPAPMI;
}
diff --git a/arch/x86/events/intel/uncore_snbep.c b/arch/x86/events/intel/uncore_snbep.c
index 272427700d48..e6832be714bc 100644
--- a/arch/x86/events/intel/uncore_snbep.c
+++ b/arch/x86/events/intel/uncore_snbep.c
@@ -669,7 +669,7 @@ static struct event_constraint snbep_uncore_cbox_constraints[] = {
UNCORE_EVENT_CONSTRAINT(0x1c, 0xc),
UNCORE_EVENT_CONSTRAINT(0x1d, 0xc),
UNCORE_EVENT_CONSTRAINT(0x1e, 0xc),
- EVENT_CONSTRAINT_OVERLAP(0x1f, 0xe, 0xff),
+ UNCORE_EVENT_CONSTRAINT(0x1f, 0xe),
UNCORE_EVENT_CONSTRAINT(0x21, 0x3),
UNCORE_EVENT_CONSTRAINT(0x23, 0x3),
UNCORE_EVENT_CONSTRAINT(0x31, 0x3),