perf: Factor out auxiliary events notification

Add perf_event_aux() function to send out all types of
auxiliary events - mmap, task, comm events. For each type
there's match and output functions defined and used as
callbacks during perf_event_aux processing.

This way we can centralize the pmu/context iterating and
event matching logic. Also since lot of the code was
duplicated, this patch reduces the .text size about 2kB
on my setup:

  snipped output from 'objdump -x kernel/events/core.o'

  before:
  Idx Name          Size
    0 .text         0000d313

  after:
  Idx Name          Size
    0 .text         0000cad3

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/1367857638-27631-3-git-send-email-jolsa@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 38b68a05c3c6ba6cbf57a25c27b28e3075f72e61..9dc297faf7c01b68cbb1a7a24444b99c300cb8a3 100644 (file)
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4394,6 +4394,64 @@ perf_event_read_event(struct perf_event *event,
        perf_output_end(&handle);
 }
 
+typedef int  (perf_event_aux_match_cb)(struct perf_event *event, void *data);
+typedef void (perf_event_aux_output_cb)(struct perf_event *event, void *data);
+
+static void
+perf_event_aux_ctx(struct perf_event_context *ctx,
+                  perf_event_aux_match_cb match,
+                  perf_event_aux_output_cb output,
+                  void *data)
+{
+       struct perf_event *event;
+
+       list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
+               if (event->state < PERF_EVENT_STATE_INACTIVE)
+                       continue;
+               if (!event_filter_match(event))
+                       continue;
+               if (match(event, data))
+                       output(event, data);
+       }
+}
+
+static void
+perf_event_aux(perf_event_aux_match_cb match,
+              perf_event_aux_output_cb output,
+              void *data,
+              struct perf_event_context *task_ctx)
+{
+       struct perf_cpu_context *cpuctx;
+       struct perf_event_context *ctx;
+       struct pmu *pmu;
+       int ctxn;
+
+       rcu_read_lock();
+       list_for_each_entry_rcu(pmu, &pmus, entry) {
+               cpuctx = get_cpu_ptr(pmu->pmu_cpu_context);
+               if (cpuctx->unique_pmu != pmu)
+                       goto next;
+               perf_event_aux_ctx(&cpuctx->ctx, match, output, data);
+               if (task_ctx)
+                       goto next;
+               ctxn = pmu->task_ctx_nr;
+               if (ctxn < 0)
+                       goto next;
+               ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
+               if (ctx)
+                       perf_event_aux_ctx(ctx, match, output, data);
+next:
+               put_cpu_ptr(pmu->pmu_cpu_context);
+       }
+
+       if (task_ctx) {
+               preempt_disable();
+               perf_event_aux_ctx(task_ctx, match, output, data);
+               preempt_enable();
+       }
+       rcu_read_unlock();
+}
+
 /*
  * task tracking -- fork/exit
  *
@@ -4416,8 +4474,9 @@ struct perf_task_event {
 };
 
 static void perf_event_task_output(struct perf_event *event,
-                                    struct perf_task_event *task_event)
+                                  void *data)
 {
+       struct perf_task_event *task_event = data;
        struct perf_output_handle handle;
        struct perf_sample_data sample;
        struct task_struct *task = task_event->task;
@@ -4445,64 +4504,11 @@ out:
        task_event->event_id.header.size = size;
 }
 
-static int perf_event_task_match(struct perf_event *event)
-{
-       if (event->state < PERF_EVENT_STATE_INACTIVE)
-               return 0;
-
-       if (!event_filter_match(event))
-               return 0;
-
-       if (event->attr.comm || event->attr.mmap ||
-           event->attr.mmap_data || event->attr.task)
-               return 1;
-
-       return 0;
-}
-
-static void perf_event_task_ctx(struct perf_event_context *ctx,
-                                 struct perf_task_event *task_event)
-{
-       struct perf_event *event;
-
-       list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
-               if (perf_event_task_match(event))
-                       perf_event_task_output(event, task_event);
-       }
-}
-
-static void perf_event_task_event(struct perf_task_event *task_event)
+static int perf_event_task_match(struct perf_event *event,
+                                void *data __maybe_unused)
 {
-       struct perf_cpu_context *cpuctx;
-       struct perf_event_context *ctx, *task_ctx = task_event->task_ctx;
-       struct pmu *pmu;
-       int ctxn;
-
-       rcu_read_lock();
-       list_for_each_entry_rcu(pmu, &pmus, entry) {
-               cpuctx = get_cpu_ptr(pmu->pmu_cpu_context);
-               if (cpuctx->unique_pmu != pmu)
-                       goto next;
-               perf_event_task_ctx(&cpuctx->ctx, task_event);
-
-               if (task_ctx)
-                       goto next;
-               ctxn = pmu->task_ctx_nr;
-               if (ctxn < 0)
-                       goto next;
-               ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
-               if (ctx)
-                       perf_event_task_ctx(ctx, task_event);
-next:
-               put_cpu_ptr(pmu->pmu_cpu_context);
-       }
-       if (task_ctx) {
-               preempt_disable();
-               perf_event_task_ctx(task_ctx, task_event);
-               preempt_enable();
-       }
-
-       rcu_read_unlock();
+       return event->attr.comm || event->attr.mmap ||
+              event->attr.mmap_data || event->attr.task;
 }
 
 static void perf_event_task(struct task_struct *task,
@@ -4533,7 +4539,10 @@ static void perf_event_task(struct task_struct *task,
                },
        };
 
-       perf_event_task_event(&task_event);
+       perf_event_aux(perf_event_task_match,
+                      perf_event_task_output,
+                      &task_event,
+                      task_ctx);
 }
 
 void perf_event_fork(struct task_struct *task)
@@ -4559,8 +4568,9 @@ struct perf_comm_event {
 };
 
 static void perf_event_comm_output(struct perf_event *event,
-                                    struct perf_comm_event *comm_event)
+                                  void *data)
 {
+       struct perf_comm_event *comm_event = data;
        struct perf_output_handle handle;
        struct perf_sample_data sample;
        int size = comm_event->event_id.header.size;
@@ -4587,39 +4597,16 @@ out:
        comm_event->event_id.header.size = size;
 }
 
-static int perf_event_comm_match(struct perf_event *event)
-{
-       if (event->state < PERF_EVENT_STATE_INACTIVE)
-               return 0;
-
-       if (!event_filter_match(event))
-               return 0;
-
-       if (event->attr.comm)
-               return 1;
-
-       return 0;
-}
-
-static void perf_event_comm_ctx(struct perf_event_context *ctx,
-                                 struct perf_comm_event *comm_event)
+static int perf_event_comm_match(struct perf_event *event,
+                                void *data __maybe_unused)
 {
-       struct perf_event *event;
-
-       list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
-               if (perf_event_comm_match(event))
-                       perf_event_comm_output(event, comm_event);
-       }
+       return event->attr.comm;
 }
 
 static void perf_event_comm_event(struct perf_comm_event *comm_event)
 {
-       struct perf_cpu_context *cpuctx;
-       struct perf_event_context *ctx;
        char comm[TASK_COMM_LEN];
        unsigned int size;
-       struct pmu *pmu;
-       int ctxn;
 
        memset(comm, 0, sizeof(comm));
        strlcpy(comm, comm_event->task->comm, sizeof(comm));
@@ -4629,24 +4616,11 @@ static void perf_event_comm_event(struct perf_comm_event *comm_event)
        comm_event->comm_size = size;
 
        comm_event->event_id.header.size = sizeof(comm_event->event_id) + size;
-       rcu_read_lock();
-       list_for_each_entry_rcu(pmu, &pmus, entry) {
-               cpuctx = get_cpu_ptr(pmu->pmu_cpu_context);
-               if (cpuctx->unique_pmu != pmu)
-                       goto next;
-               perf_event_comm_ctx(&cpuctx->ctx, comm_event);
 
-               ctxn = pmu->task_ctx_nr;
-               if (ctxn < 0)
-                       goto next;
-
-               ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
-               if (ctx)
-                       perf_event_comm_ctx(ctx, comm_event);
-next:
-               put_cpu_ptr(pmu->pmu_cpu_context);
-       }
-       rcu_read_unlock();
+       perf_event_aux(perf_event_comm_match,
+                      perf_event_comm_output,
+                      comm_event,
+                      NULL);
 }
 
 void perf_event_comm(struct task_struct *task)
@@ -4708,8 +4682,9 @@ struct perf_mmap_event {
 };
 
 static void perf_event_mmap_output(struct perf_event *event,
-                                    struct perf_mmap_event *mmap_event)
+                                  void *data)
 {
+       struct perf_mmap_event *mmap_event = data;
        struct perf_output_handle handle;
        struct perf_sample_data sample;
        int size = mmap_event->event_id.header.size;
@@ -4736,46 +4711,24 @@ out:
 }
 
 static int perf_event_mmap_match(struct perf_event *event,
-                                  struct perf_mmap_event *mmap_event,
-                                  int executable)
+                                void *data)
 {
-       if (event->state < PERF_EVENT_STATE_INACTIVE)
-               return 0;
-
-       if (!event_filter_match(event))
-               return 0;
-
-       if ((!executable && event->attr.mmap_data) ||
-           (executable && event->attr.mmap))
-               return 1;
-
-       return 0;
-}
-
-static void perf_event_mmap_ctx(struct perf_event_context *ctx,
-                                 struct perf_mmap_event *mmap_event,
-                                 int executable)
-{
-       struct perf_event *event;
+       struct perf_mmap_event *mmap_event = data;
+       struct vm_area_struct *vma = mmap_event->vma;
+       int executable = vma->vm_flags & VM_EXEC;
 
-       list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
-               if (perf_event_mmap_match(event, mmap_event, executable))
-                       perf_event_mmap_output(event, mmap_event);
-       }
+       return (!executable && event->attr.mmap_data) ||
+              (executable && event->attr.mmap);
 }
 
 static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
 {
-       struct perf_cpu_context *cpuctx;
-       struct perf_event_context *ctx;
        struct vm_area_struct *vma = mmap_event->vma;
        struct file *file = vma->vm_file;
        unsigned int size;
        char tmp[16];
        char *buf = NULL;
        const char *name;
-       struct pmu *pmu;
-       int ctxn;
 
        memset(tmp, 0, sizeof(tmp));
 
@@ -4831,27 +4784,10 @@ got_name:
 
        mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size;
 
-       rcu_read_lock();
-       list_for_each_entry_rcu(pmu, &pmus, entry) {
-               cpuctx = get_cpu_ptr(pmu->pmu_cpu_context);
-               if (cpuctx->unique_pmu != pmu)
-                       goto next;
-               perf_event_mmap_ctx(&cpuctx->ctx, mmap_event,
-                                       vma->vm_flags & VM_EXEC);
-
-               ctxn = pmu->task_ctx_nr;
-               if (ctxn < 0)
-                       goto next;
-
-               ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
-               if (ctx) {
-                       perf_event_mmap_ctx(ctx, mmap_event,
-                                       vma->vm_flags & VM_EXEC);
-               }
-next:
-               put_cpu_ptr(pmu->pmu_cpu_context);
-       }
-       rcu_read_unlock();
+       perf_event_aux(perf_event_mmap_match,
+                      perf_event_mmap_output,
+                      mmap_event,
+                      NULL);
 
        kfree(buf);
 }