From: Bojan Smojver <bojan@rexursive.com>
To: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: linux-kernel@vger.kernel.org, "Rafael J. Wysocki" <rjw@sisk.pl>
Subject: Re: [PATCH v5]: Improve performance of LZO hibernation
Date: Wed, 28 Sep 2011 17:57:29 +1000 [thread overview]
Message-ID: <1317196649.1998.27.camel@shrek.rexursive.com> (raw)
In-Reply-To: <CAOJsxLFGpU53AQRw-nKsz_Lz_QMDP+RDUD5J3bYzbAA_+ngaAA@mail.gmail.com>
On Wed, 2011-09-28 at 10:48 +0300, Pekka Enberg wrote:
> > We want to keep at least one CPU free for that I/O and for pulling
> the
> > other threads into sync when they are done (that is if we have more
> than
> > one), right?
>
> Well, dunno if it matters much. Did you see performance improvement
> with that?
Haven't tried, to be honest. Just thought it may make sense.
> Is the CPU binding really needed?
Don't really know, but I would think it would help with
compression/decompression code. We don't want these threads bouncing
between CPUs unless they have to. I would guess the caches would work
better that way and all that.
Again, just guessing.
> Anyway, if you want to keep the existing behavior, maybe something
> like
>
> nr_other_cpus = min(1, num_online_cpus()-1);
>
> nr_threads = min(nr_other_cpus, LZO_THREADS);
>
> would do the trick?
Yeah, makes sense. The first one should be max() though.
--
Bojan
next prev parent reply other threads:[~2011-09-28 7:57 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-28 4:20 [PATCH v5]: Improve performance of LZO hibernation Bojan Smojver
2011-09-28 7:14 ` Pekka Enberg
2011-09-28 7:18 ` Bojan Smojver
2011-09-28 7:25 ` Pekka Enberg
2011-09-28 7:22 ` Pekka Enberg
2011-09-28 7:29 ` Bojan Smojver
2011-09-28 7:48 ` Pekka Enberg
2011-09-28 7:54 ` Bojan Smojver
2011-09-28 13:02 ` Pekka Enberg
2011-09-28 13:18 ` Bojan Smojver
2011-09-29 8:23 ` Bojan Smojver
2011-09-28 7:57 ` Bojan Smojver [this message]
2011-09-28 8:00 ` Bojan Smojver
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