From: Nicholas Piggin <npiggin@gmail.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Anton Blanchard <anton@ozlabs.org>,
linux-kernel@vger.kernel.org, Paul McKenney <paulmck@kernel.org>
Subject: Re: [PATCH] ring-buffer: speed up buffer resets by avoiding synchronize_rcu for each CPU
Date: Tue, 30 Jun 2020 12:07:05 +1000 [thread overview]
Message-ID: <1593482725.5cl7vnne3j.astroid@bobo.none> (raw)
In-Reply-To: <20200629181625.4b87a63a@oasis.local.home>
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@gmail.com> 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
prev parent reply other threads:[~2020-06-30 2:07 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-25 5:34 [PATCH] ring-buffer: speed up buffer resets by avoiding synchronize_rcu for each CPU Nicholas Piggin
2020-06-25 21:42 ` Anton Blanchard
2020-06-29 15:35 ` Paul E. McKenney
2020-06-29 15:40 ` Steven Rostedt
2020-06-29 22:16 ` Steven Rostedt
2020-06-30 2:07 ` Nicholas Piggin [this message]
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