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From: Johannes Berg <johannes@sipsolutions.net>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: tz.stoyanov@gmail.com, linux-trace-devel@vger.kernel.org
Subject: Re: [PATCH] trace-cmd: Do not free pages from the lookup table in struct cpu_data in case trace file is loaded.
Date: Wed, 26 Jun 2019 08:51:14 +0200	[thread overview]
Message-ID: <fe27a8ed9bb297894ce97c0cfe6c801e07cf6a2c.camel@sipsolutions.net> (raw)
In-Reply-To: <20190625183245.38d63750@gandalf.local.home>

On Tue, 2019-06-25 at 18:32 -0400, Steven Rostedt wrote:
> On Wed, 19 Jun 2019 13:52:14 +0200
> Johannes Berg <johannes@sipsolutions.net> wrote:
> 
> > Seems to work, more or less. I now see ~6.5 seconds which is slower than
> > it was, and in particular comparing to just a revert (which was ~2
> > seconds), but it's usable :-)
> 
> I'm totally confused. Unless it is a cache miss thing, the only thing
> it did was add two branches that should basically follow the old path
> with the revert.
> 
> Can you run perf comparing this patch against the revert and see where
> the difference lies?

I tried, but it looks the same. Then I tried to reproduce and now I see
it also fairly consistently just under 2 seconds with the patch, so
perhaps CPU scaling or something was throwing me a curve ball before.

Sorry for the noise, patch works great.

Tested-by: Johannes Berg <johannes@sipsolutions.net>

johannes


      reply	other threads:[~2019-06-26  6:51 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-19 11:49 [PATCH] trace-cmd: Do not free pages from the lookup table in struct cpu_data in case trace file is loaded tz.stoyanov
2019-06-19 11:52 ` Johannes Berg
2019-06-25 22:32   ` Steven Rostedt
2019-06-26  6:51     ` Johannes Berg [this message]

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