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| author |   Takashi Iwai <tiwai@suse.de> | 2012-08-03 12:59:38 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2012-08-03 12:59:38 +0200 |
| commit | d30a0d839a5a282e43353fee53d5dc70db5eceda (patch) | |
| tree | 189a91615be3174a9ff8b20937359d11298433af /kernel/trace/ring_buffer.c | |
| parent | ALSA: emu10k1: Avoid access to invalid pages when period=1 (diff) | |
| parent | ALSA: isa: Move snd_legacy_find_free_ioport to initval.h (diff) | |
| download | linux-dev-d30a0d839a5a282e43353fee53d5dc70db5eceda.tar.xz linux-dev-d30a0d839a5a282e43353fee53d5dc70db5eceda.zip | |
Merge branch 'topic/next' into for-next
Diffstat (limited to 'kernel/trace/ring_buffer.c')
| -rw-r--r-- | kernel/trace/ring_buffer.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 1d0f6a8a0e5e..49491fa7daa2 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1075,6 +1075,7 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int nr_pages, int cpu) rb_init_page(bpage->page); INIT_LIST_HEAD(&cpu_buffer->reader_page->list); + INIT_LIST_HEAD(&cpu_buffer->new_pages); ret = rb_allocate_pages(cpu_buffer, nr_pages); if (ret < 0) @@ -1346,10 +1347,9 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned int nr_pages) * If something was added to this page, it was full * since it is not the tail page. So we deduct the * bytes consumed in ring buffer from here. - * No need to update overruns, since this page is - * deleted from ring buffer and its entries are - * already accounted for. + * Increment overrun to account for the lost events. */ + local_add(page_entries, &cpu_buffer->overrun); local_sub(BUF_PAGE_SIZE, &cpu_buffer->entries_bytes); } @@ -3239,6 +3239,10 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer) if (cpu_buffer->commit_page == cpu_buffer->reader_page) goto out; + /* Don't bother swapping if the ring buffer is empty */ + if (rb_num_of_entries(cpu_buffer) == 0) + goto out; + /* * Reset the reader page to size zero. */ |