From 1e0fb9ec679c9273a641f1d6f3d25ea47baef2bb Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Fri, 24 Oct 2014 15:58:10 -0700 Subject: [PATCH] perf: Add pmu callbacks to track event mapping and unmapping Signed-off-by: Andy Lutomirski Signed-off-by: Peter Zijlstra (Intel) Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Kees Cook Cc: Andrea Arcangeli Cc: Vince Weaver Cc: "hillf.zj" Cc: Valdis Kletnieks Cc: Linus Torvalds Link: http://lkml.kernel.org/r/266afcba1d1f91ea5501e4e16e94bbbc1a9339b6.1414190806.git.luto@amacapital.net Signed-off-by: Ingo Molnar --- include/linux/perf_event.h | 7 +++++++ kernel/events/core.c | 9 +++++++++ 2 files changed, 16 insertions(+) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 5cad0e6f3552..33262004c310 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -202,6 +202,13 @@ struct pmu { */ int (*event_init) (struct perf_event *event); + /* + * Notification that the event was mapped or unmapped. Called + * in the context of the mapping task. + */ + void (*event_mapped) (struct perf_event *event); /*optional*/ + void (*event_unmapped) (struct perf_event *event); /*optional*/ + #define PERF_EF_START 0x01 /* start the counter when adding */ #define PERF_EF_RELOAD 0x02 /* reload the counter when starting */ #define PERF_EF_UPDATE 0x04 /* update the counter when stopping */ diff --git a/kernel/events/core.c b/kernel/events/core.c index 7f2fbb8b5069..cc1487145d33 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4293,6 +4293,9 @@ static void perf_mmap_open(struct vm_area_struct *vma) atomic_inc(&event->mmap_count); atomic_inc(&event->rb->mmap_count); + + if (event->pmu->event_mapped) + event->pmu->event_mapped(event); } /* @@ -4312,6 +4315,9 @@ static void perf_mmap_close(struct vm_area_struct *vma) int mmap_locked = rb->mmap_locked; unsigned long size = perf_data_size(rb); + if (event->pmu->event_unmapped) + event->pmu->event_unmapped(event); + atomic_dec(&rb->mmap_count); if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) @@ -4513,6 +4519,9 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP; vma->vm_ops = &perf_mmap_vmops; + if (event->pmu->event_mapped) + event->pmu->event_mapped(event); + return ret; } -- GitLab