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authorKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2012-08-13 15:39:10 -0400
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2012-08-13 15:39:10 -0400
commit0980bd9cd32de2fef7eaa2858345c49d14498625 (patch)
tree41f5f823d0569a81b22037e79c22d823933a63f1 /kernel/trace/ring_buffer.c
parent78821b2c0299ab807d483802f09897728b93bce0 (diff)
parent0d7614f09c1ebdbaa1599a5aba7593f147bf96ee (diff)
Merge commit 'v3.6-rc1' into linux-next
* commit 'v3.6-rc1': (9532 commits) Linux 3.6-rc1 mm: remove node_start_pfn checking in new WARN_ON for now ARM: mmp: add missing irqs.h arm: mvebu: fix typo in .dtsi comment for Armada XP SoCs ARM: PRIMA2: delete redundant codes to restore LATCHED when timer resumes libceph: fix crypto key null deref, memory leak ceph: simplify+fix atomic_open sh: explicitly include sh_dma.h in setup-sh7722.c um: Add arch/x86/um to MAINTAINERS um: pass siginfo to guest process um: fix ubd_file_size for read-only files md/dm-raid: DM_RAID should select MD_RAID10 md/raid1: submit IO from originating thread instead of md thread. raid5: raid5d handle stripe in batch way raid5: make_request use batch stripe release um: pull interrupt_end() into userspace() um: split syscall_trace(), pass pt_regs to it um: switch UPT_SET_RETURN_VALUE and regs_return_value to pt_regs MIPS: Loongson 2: Sort out clock managment. locks: remove unused lm_release_private ...
Diffstat (limited to 'kernel/trace/ring_buffer.c')
-rw-r--r--kernel/trace/ring_buffer.c10
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.
*/