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>

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)				{ }

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 @@ perf_counter_alloc(struct perf_counter_attr *attr,
 	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);
 

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);