Re: [PATCH] ring-buffer: speed up buffer resets by avoiding synchronize_rcu for each CPU

[Nicholas Piggin]

Excerpts from Steven Rostedt's message of June 30, 2020 8:16 am:
> On Thu, 25 Jun 2020 15:34:03 +1000
> Nicholas Piggin <npiggin@xxxxxxxxx> wrote:
> 
>> Batch these up so we disable all the per-cpu buffers first, then
>> synchronize_rcu() once, then reset each of the buffers. This brings
>> the time down to about 0.5s.
> 
> After applying this patch, running tools/testing/selftests/ftracetest
> went from 5 minutes and 35 seconds to 5 minutes 5 seconds to complete
> on my 4 core (8 with hyperthreading) machine! That's almost a 10% drop!
> 
> Thanks, I'm definitely applying this for the next merge window.

Cool, always good when a big system optimisation helps small ones as 
well. Thanks all.

Thanks,
Nick