perf_counter: Remove munmap stuff

In name of keeping it simple, only track mmap events. Userspace
will have to remove old overlapping maps when it encounters them.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 4 insertions, 51 deletions

diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h
index 380247bdb918..6ca403acd419 100644
--- a/include/linux/perf_counter.h
+++ b/include/linux/perf_counter.h
@@ -148,11 +148,10 @@ struct perf_counter_attr {
                                 exclude_hv     :  1, /* ditto hypervisor      */
                                 exclude_idle   :  1, /* don't count when idle */
                                 mmap           :  1, /* include mmap data     */
-                                munmap         :  1, /* include munmap data   */
                                 comm           :  1, /* include comm data     */
                                 freq           :  1, /* use freq, not period  */
 
-                                __reserved_1   : 52;
+                                __reserved_1   : 53;
 
         __u32                   wakeup_events;  /* wakeup every n events */
         __u32                   __reserved_2;
@@ -246,7 +245,6 @@ enum perf_event_type {
          * };
          */
         PERF_EVENT_MMAP                 = 1,
-        PERF_EVENT_MUNMAP               = 2,
 
         /*
          * struct {
@@ -622,9 +620,6 @@ extern void perf_swcounter_event(u32, u64, int, struct pt_regs *, u64);
 extern void perf_counter_mmap(unsigned long addr, unsigned long len,
                               unsigned long pgoff, struct file *file);
 
-extern void perf_counter_munmap(unsigned long addr, unsigned long len,
-                                unsigned long pgoff, struct file *file);
-
 extern void perf_counter_comm(struct task_struct *tsk);
 extern void perf_counter_fork(struct task_struct *tsk);
 
@@ -677,10 +672,6 @@ static inline void
 perf_counter_mmap(unsigned long addr, unsigned long len,
                   unsigned long pgoff, struct file *file)               { }
 
-static inline void
-perf_counter_munmap(unsigned long addr, unsigned long len,
-                    unsigned long pgoff, struct file *file)             { }
-
 static inline void perf_counter_comm(struct task_struct *tsk)           { }
 static inline void perf_counter_fork(struct task_struct *tsk)           { }
 static inline void perf_counter_init(void)                              { }
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index 78c58623a0dd..195712e20d07 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -41,7 +41,6 @@ static int perf_overcommit __read_mostly = 1;
 
 static atomic_t nr_counters __read_mostly;
 static atomic_t nr_mmap_counters __read_mostly;
-static atomic_t nr_munmap_counters __read_mostly;
 static atomic_t nr_comm_counters __read_mostly;
 
 int sysctl_perf_counter_priv __read_mostly; /* do we need to be privileged */
@@ -1448,8 +1447,6 @@ static void free_counter(struct perf_counter *counter)
         atomic_dec(&nr_counters);
         if (counter->attr.mmap)
                 atomic_dec(&nr_mmap_counters);
-        if (counter->attr.munmap)
-                atomic_dec(&nr_munmap_counters);
         if (counter->attr.comm)
                 atomic_dec(&nr_comm_counters);
 
@@ -2510,7 +2507,7 @@ static void perf_counter_fork_output(struct perf_counter *counter,
 
 static int perf_counter_fork_match(struct perf_counter *counter)
 {
-        if (counter->attr.comm || counter->attr.mmap || counter->attr.munmap)
+        if (counter->attr.comm || counter->attr.mmap)
                 return 1;
 
         return 0;
@@ -2557,8 +2554,7 @@ void perf_counter_fork(struct task_struct *task)
         struct perf_fork_event fork_event;
 
         if (!atomic_read(&nr_comm_counters) &&
-            !atomic_read(&nr_mmap_counters) &&
-            !atomic_read(&nr_munmap_counters))
+            !atomic_read(&nr_mmap_counters))
                 return;
 
         fork_event = (struct perf_fork_event){
@@ -2722,12 +2718,7 @@ static void perf_counter_mmap_output(struct perf_counter *counter,
 static int perf_counter_mmap_match(struct perf_counter *counter,
                                    struct perf_mmap_event *mmap_event)
 {
-        if (counter->attr.mmap &&
-            mmap_event->event.header.type == PERF_EVENT_MMAP)
-                return 1;
-
-        if (counter->attr.munmap &&
-            mmap_event->event.header.type == PERF_EVENT_MUNMAP)
+        if (counter->attr.mmap)
                 return 1;
 
         return 0;
@@ -2821,27 +2812,6 @@ void perf_counter_mmap(unsigned long addr, unsigned long len,
         perf_counter_mmap_event(&mmap_event);
 }
 
-void perf_counter_munmap(unsigned long addr, unsigned long len,
-                         unsigned long pgoff, struct file *file)
-{
-        struct perf_mmap_event mmap_event;
-
-        if (!atomic_read(&nr_munmap_counters))
-                return;
-
-        mmap_event = (struct perf_mmap_event){
-                .file   = file,
-                .event  = {
-                        .header = { .type = PERF_EVENT_MUNMAP, },
-                        .start  = addr,
-                        .len    = len,
-                        .pgoff  = pgoff,
-                },
-        };
-
-        perf_counter_mmap_event(&mmap_event);
-}
-
 /*
  * Log sample_period changes so that analyzing tools can re-normalize the
  * event flow.
@@ -3525,8 +3495,6 @@ done:
         atomic_inc(&nr_counters);
         if (counter->attr.mmap)
                 atomic_inc(&nr_mmap_counters);
-        if (counter->attr.munmap)
-                atomic_inc(&nr_munmap_counters);
         if (counter->attr.comm)
                 atomic_inc(&nr_comm_counters);
 
diff --git a/mm/mmap.c b/mm/mmap.c
index 2c1c2cb0e2e1..6451ce2854b9 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1756,12 +1756,6 @@ static void remove_vma_list(struct mm_struct *mm, struct vm_area_struct *vma)
         do {
                 long nrpages = vma_pages(vma);
 
-                if (vma->vm_flags & VM_EXEC) {
-                        perf_counter_munmap(vma->vm_start,
-                                        nrpages << PAGE_SHIFT,
-                                        vma->vm_pgoff, vma->vm_file);
-                }
-
                 mm->total_vm -= nrpages;
                 vm_stat_account(mm, vma->vm_flags, vma->vm_file, -nrpages);
                 vma = remove_vma(vma);