On Mon, 30 Mar 2026 14:36:13 -0400 Steven Rostedt <[email protected]> wrote:
> On Mon, 30 Mar 2026 21:50:20 +0900 > "Masami Hiramatsu (Google)" <[email protected]> wrote: > > > From: Masami Hiramatsu (Google) <[email protected]> > > > > Reset RB_MISSED_* flags when the persistent ring buffer is > > validated at boot. Since these flags are used only in reading > > process, such process should be stopped when reboot and never > > be restarted. Thus, these flags are meaningless in the next > > boot. Moreover, it can confuse the read process after reboot. > > Is it meaningless on a second boot? > > Let's say you have a crash, and there's an invalid buffer. On the next boot > it is flagged as invalid with the RB_MISSED flag. But then you reboot again > before looking at the buffer. The next boot will clear this flag. Now > looking at the persistent ring buffer will not show any missed events. > > Ideally, it shouldn't matter how many reboots are made. If the persistent > ring buffer hasn't started again, it should always show the same output. Hmm, OK. I'll drop this. Thanks! > > -- Steve > > > > > > Signed-off-by: Masami Hiramatsu (Google) <[email protected]> > > --- > > Changes in v14: > > - Newly added. > > --- > > kernel/trace/ring_buffer.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c > > index e5178239f2f9..5049cf13021e 100644 > > --- a/kernel/trace/ring_buffer.c > > +++ b/kernel/trace/ring_buffer.c > > @@ -1903,6 +1903,7 @@ static int rb_validate_buffer(struct buffer_page > > *bpage, int cpu, > > local_set(&bpage->page->commit, 0); > > } else { > > local_set(&bpage->entries, ret); > > + local_set(&bpage->page->commit, tail); > > } > > > > return ret; > > -- Masami Hiramatsu (Google) <[email protected]>
