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| author | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2021-03-03 18:23:40 -0500 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2021-03-04 09:45:17 -0500 |
| commit | 6549de1fe34162d7ace8b870ae11ca6cae5b8609 (patch) | |
| tree | 0a599caa84e7417fc480554b156646bb4c4d4f8b /kernel | |
| parent | 6f6be606e763f2da9fc21de00538c97fe4ca1492 (diff) | |
| download | lwn-6549de1fe34162d7ace8b870ae11ca6cae5b8609.tar.gz lwn-6549de1fe34162d7ace8b870ae11ca6cae5b8609.zip | |
ring-buffer: Add a little more information and a WARN when time stamp going backwards is detected
When the CONFIG_RING_BUFFER_VALIDATE_TIME_DELTAS is enabled, and the time
stamps are detected as not being valid, it reports information about the
write stamp, but does not show the before_stamp which is still useful
information. Also, it should give a warning once, such that tests detect
this happening.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -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 342f49c3ccc5..68744c51517e 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -3318,9 +3318,13 @@ static void check_buffer(struct ring_buffer_per_cpu *cpu_buffer, goto out; } atomic_inc(&cpu_buffer->record_disabled); - pr_warn("[CPU: %d]TIME DOES NOT MATCH expected:%lld actual:%lld delta:%lld after:%lld\n", - cpu_buffer->cpu, - ts + info->delta, info->ts, info->delta, info->after); + /* There's some cases in boot up that this can happen */ + WARN_ON_ONCE(system_state != SYSTEM_BOOTING); + pr_warn("[CPU: %d]TIME DOES NOT MATCH expected:%lld actual:%lld delta:%lld before:%lld after:%lld%s\n", + cpu_buffer->cpu, + ts + info->delta, info->ts, info->delta, + info->before, info->after, + full ? " (full)" : ""); dump_buffer_page(bpage, info, tail); atomic_dec(&ts_dump); /* Do not re-enable checking */ |