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| author | Peter Zijlstra <peterz@infradead.org> | 2016-07-06 18:02:43 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-08-10 13:13:24 +0200 |
| commit | 68f7082ffb0575154ccdec36109e293174f48a4c (patch) | |
| tree | a8e84e19012fc10261534e929bb9e553a55b07e8 /arch/x86/events/core.c | |
| parent | 09e61b4f78498bd9f213b0a536e80b79507ea89f (diff) | |
| download | linux-0-day-68f7082ffb0575154ccdec36109e293174f48a4c.tar.gz linux-0-day-68f7082ffb0575154ccdec36109e293174f48a4c.tar.xz | |
perf/x86: Ensure perf_sched_cb_{inc,dec}() is only called from pmu::{add,del}()
Currently perf_sched_cb_{inc,dec}() are called from
pmu::{start,stop}(), which has the problem that this can happen from
NMI context, this is making it hard to optimize perf_pmu_sched_task().
Furthermore, we really only need this accounting on pmu::{add,del}(),
so doing it from pmu::{start,stop}() is doing more work than we really
need.
Introduce x86_pmu::{add,del}() and wire up the LBR and PEBS.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.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: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/events/core.c')
| -rw-r--r-- | arch/x86/events/core.c | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c index d0efb5cb1b00e..18a1acf86c907 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -1201,6 +1201,9 @@ static int x86_pmu_add(struct perf_event *event, int flags) * If group events scheduling transaction was started, * skip the schedulability test here, it will be performed * at commit time (->commit_txn) as a whole. + * + * If commit fails, we'll call ->del() on all events + * for which ->add() was called. */ if (cpuc->txn_flags & PERF_PMU_TXN_ADD) goto done_collect; @@ -1223,6 +1226,14 @@ done_collect: cpuc->n_added += n - n0; cpuc->n_txn += n - n0; + if (x86_pmu.add) { + /* + * This is before x86_pmu_enable() will call x86_pmu_start(), + * so we enable LBRs before an event needs them etc.. + */ + x86_pmu.add(event); + } + ret = 0; out: return ret; @@ -1346,7 +1357,7 @@ static void x86_pmu_del(struct perf_event *event, int flags) event->hw.flags &= ~PERF_X86_EVENT_COMMITTED; /* - * If we're called during a txn, we don't need to do anything. + * If we're called during a txn, we only need to undo x86_pmu.add. * The events never got scheduled and ->cancel_txn will truncate * the event_list. * @@ -1354,7 +1365,7 @@ static void x86_pmu_del(struct perf_event *event, int flags) * an event added during that same TXN. */ if (cpuc->txn_flags & PERF_PMU_TXN_ADD) - return; + goto do_del; /* * Not a TXN, therefore cleanup properly. @@ -1384,6 +1395,15 @@ static void x86_pmu_del(struct perf_event *event, int flags) --cpuc->n_events; perf_event_update_userpage(event); + +do_del: + if (x86_pmu.del) { + /* + * This is after x86_pmu_stop(); so we disable LBRs after any + * event can need them etc.. + */ + x86_pmu.del(event); + } } int x86_pmu_handle_irq(struct pt_regs *regs) |