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-rw-r--r--kernel/events/ring_buffer.c47
1 files changed, 27 insertions, 20 deletions
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index 2831480c63a2..f3e37971c842 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -367,7 +367,7 @@ void *perf_aux_output_begin(struct perf_output_handle *handle,
if (WARN_ON_ONCE(local_xchg(&rb->aux_nest, 1)))
goto err_put;
- aux_head = local_read(&rb->aux_head);
+ aux_head = rb->aux_head;
handle->rb = rb;
handle->event = event;
@@ -381,8 +381,8 @@ void *perf_aux_output_begin(struct perf_output_handle *handle,
* (B) <-> (C) ordering is still observed by the pmu driver.
*/
if (!rb->aux_overwrite) {
- aux_tail = ACCESS_ONCE(rb->user_page->aux_tail);
- handle->wakeup = local_read(&rb->aux_wakeup) + rb->aux_watermark;
+ aux_tail = READ_ONCE(rb->user_page->aux_tail);
+ handle->wakeup = rb->aux_wakeup + rb->aux_watermark;
if (aux_head - aux_tail < perf_aux_size(rb))
handle->size = CIRC_SPACE(aux_head, aux_tail, perf_aux_size(rb));
@@ -412,6 +412,19 @@ err:
return NULL;
}
+static bool __always_inline rb_need_aux_wakeup(struct ring_buffer *rb)
+{
+ if (rb->aux_overwrite)
+ return false;
+
+ if (rb->aux_head - rb->aux_wakeup >= rb->aux_watermark) {
+ rb->aux_wakeup = rounddown(rb->aux_head, rb->aux_watermark);
+ return true;
+ }
+
+ return false;
+}
+
/*
* Commit the data written by hardware into the ring buffer by adjusting
* aux_head and posting a PERF_RECORD_AUX into the perf buffer. It is the
@@ -433,12 +446,12 @@ void perf_aux_output_end(struct perf_output_handle *handle, unsigned long size)
handle->aux_flags |= PERF_AUX_FLAG_OVERWRITE;
aux_head = handle->head;
- local_set(&rb->aux_head, aux_head);
+ rb->aux_head = aux_head;
} else {
handle->aux_flags &= ~PERF_AUX_FLAG_OVERWRITE;
- aux_head = local_read(&rb->aux_head);
- local_add(size, &rb->aux_head);
+ aux_head = rb->aux_head;
+ rb->aux_head += size;
}
if (size || handle->aux_flags) {
@@ -450,12 +463,9 @@ void perf_aux_output_end(struct perf_output_handle *handle, unsigned long size)
handle->aux_flags);
}
- aux_head = rb->user_page->aux_head = local_read(&rb->aux_head);
-
- if (aux_head - local_read(&rb->aux_wakeup) >= rb->aux_watermark) {
+ rb->user_page->aux_head = rb->aux_head;
+ if (rb_need_aux_wakeup(rb))
wakeup = true;
- local_add(rb->aux_watermark, &rb->aux_wakeup);
- }
if (wakeup) {
if (handle->aux_flags & PERF_AUX_FLAG_TRUNCATED)
@@ -478,22 +488,19 @@ void perf_aux_output_end(struct perf_output_handle *handle, unsigned long size)
int perf_aux_output_skip(struct perf_output_handle *handle, unsigned long size)
{
struct ring_buffer *rb = handle->rb;
- unsigned long aux_head;
if (size > handle->size)
return -ENOSPC;
- local_add(size, &rb->aux_head);
+ rb->aux_head += size;
- aux_head = rb->user_page->aux_head = local_read(&rb->aux_head);
- if (aux_head - local_read(&rb->aux_wakeup) >= rb->aux_watermark) {
+ rb->user_page->aux_head = rb->aux_head;
+ if (rb_need_aux_wakeup(rb)) {
perf_output_wakeup(handle);
- local_add(rb->aux_watermark, &rb->aux_wakeup);
- handle->wakeup = local_read(&rb->aux_wakeup) +
- rb->aux_watermark;
+ handle->wakeup = rb->aux_wakeup + rb->aux_watermark;
}
- handle->head = aux_head;
+ handle->head = rb->aux_head;
handle->size -= size;
return 0;
@@ -580,7 +587,7 @@ int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event,
int ret = -ENOMEM, max_order = 0;
if (!has_aux(event))
- return -ENOTSUPP;
+ return -EOPNOTSUPP;
if (event->pmu->capabilities & PERF_PMU_CAP_AUX_NO_SG) {
/*