From: Steven Rostedt (VMware) Date: Wed, 3 Mar 2021 23:23:40 +0000 (-0500) Subject: ring-buffer: Add a little more information and a WARN when time stamp going backwards... X-Git-Tag: accepted/tizen/unified/20230118.172025~7691^2~3 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=6549de1fe34162d7ace8b870ae11ca6cae5b8609;p=platform%2Fkernel%2Flinux-rpi.git 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) --- diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 342f49c..68744c5 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 */