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authorIngo Molnar <mingo@kernel.org>2014-08-22 10:04:15 +0200
committerIngo Molnar <mingo@kernel.org>2014-08-22 10:04:15 +0200
commit80b304fd00e8b667775ff791121b61ecd7cd0c03 (patch)
treeb4f2ec59fe062c43343ee4c2f10a6bcd0e4dcd1b /kernel/trace/ring_buffer.c
parentx86_32, entry: Clean up sysenter_badsys declaration (diff)
parentefi/arm64: Store Runtime Services revision (diff)
downloadwireguard-linux-80b304fd00e8b667775ff791121b61ecd7cd0c03.tar.xz
wireguard-linux-80b304fd00e8b667775ff791121b61ecd7cd0c03.zip
Merge tag 'efi-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/urgent
Pull EFI fixes from Matt Fleming: * WARN_ON(!spin_is_locked()) always triggers on non-SMP machines. Swap it for the more canonical lockdep_assert_held() which always does the right thing - Guenter Roeck * Assign the correct value to efi.runtime_version on arm64 so that all the runtime services can be invoked - Semen Protsenko Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/trace/ring_buffer.c')
-rw-r--r--kernel/trace/ring_buffer.c31
1 files changed, 14 insertions, 17 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 925f629658d6..afb04b9b818a 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1968,7 +1968,7 @@ rb_add_time_stamp(struct ring_buffer_event *event, u64 delta)
/**
* rb_update_event - update event type and data
- * @event: the even to update
+ * @event: the event to update
* @type: the type of event
* @length: the size of the event field in the ring buffer
*
@@ -3341,21 +3341,16 @@ static void rb_iter_reset(struct ring_buffer_iter *iter)
struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer;
/* Iterator usage is expected to have record disabled */
- if (list_empty(&cpu_buffer->reader_page->list)) {
- iter->head_page = rb_set_head_page(cpu_buffer);
- if (unlikely(!iter->head_page))
- return;
- iter->head = iter->head_page->read;
- } else {
- iter->head_page = cpu_buffer->reader_page;
- iter->head = cpu_buffer->reader_page->read;
- }
+ iter->head_page = cpu_buffer->reader_page;
+ iter->head = cpu_buffer->reader_page->read;
+
+ iter->cache_reader_page = iter->head_page;
+ iter->cache_read = iter->head;
+
if (iter->head)
iter->read_stamp = cpu_buffer->read_stamp;
else
iter->read_stamp = iter->head_page->page->time_stamp;
- iter->cache_reader_page = cpu_buffer->reader_page;
- iter->cache_read = cpu_buffer->read;
}
/**
@@ -3748,12 +3743,14 @@ rb_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
return NULL;
/*
- * We repeat when a time extend is encountered.
- * Since the time extend is always attached to a data event,
- * we should never loop more than once.
- * (We never hit the following condition more than twice).
+ * We repeat when a time extend is encountered or we hit
+ * the end of the page. Since the time extend is always attached
+ * to a data event, we should never loop more than three times.
+ * Once for going to next page, once on time extend, and
+ * finally once to get the event.
+ * (We never hit the following condition more than thrice).
*/
- if (RB_WARN_ON(cpu_buffer, ++nr_loops > 2))
+ if (RB_WARN_ON(cpu_buffer, ++nr_loops > 3))
return NULL;
if (rb_per_cpu_empty(cpu_buffer))