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From: Pete Wyckoff <pw@padd.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Junio C Hamano <gitster@pobox.com>,
	Git Mailing List <git@vger.kernel.org>
Subject: Re: "git grep" parallelism question
Date: Sun, 5 May 2013 11:40:01 -0400	[thread overview]
Message-ID: <20130505154001.GA25257@padd.com> (raw)
In-Reply-To: <CA+55aFx1t_MT+20Bbkse-wHeLz8E06yqaOhbb12GzHNDrE2tWA@mail.gmail.com>

torvalds@linux-foundation.org wrote on Fri, 26 Apr 2013 13:31 -0700:
> Anyway, I think your patch is good if for no other reason that it
> allows this kind of testing, but at least for my machine, clearly the
> current default of eight threads is actually "good enough". Maybe
> somebody with a very different machine might want to run the above
> script and see if how sensitive other machines are to this parameter..

NFS numbers behave as expected:  IO concurrency is key.

WARM
1 real 0m23.147s
2 real 0m13.913s
4 real 0m6.958s
8 real 0m4.104s
16 real 0m3.588s
32 real 0m3.212s
64 real 0m3.173s

COLD
1 real 1m36.969s
2 real 0m51.627s
4 real 0m32.994s
8 real 0m25.657s
16 real 0m21.260s
32 real 0m18.138s
64 real 0m17.265s

I am tempted to change the default locally from 8 to 32.

		-- Pete

      parent reply	other threads:[~2013-05-05 15:40 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-26 17:31 "git grep" parallelism question Linus Torvalds
2013-04-26 18:47 ` Junio C Hamano
2013-04-26 18:54   ` Linus Torvalds
2013-04-26 19:19     ` Junio C Hamano
2013-04-26 20:31       ` Linus Torvalds
2013-04-27 13:46         ` Thomas Rast
2013-04-29 14:05         ` Ramkumar Ramachandra
2013-04-29 16:18           ` John Keeping
2013-04-29 18:04             ` Thomas Rast
2013-04-29 18:08               ` John Keeping
2013-04-29 22:22                 ` Junio C Hamano
2013-04-30  8:08                   ` John Keeping
2013-04-30 15:59                     ` Jeff King
2013-04-30 16:12                       ` John Keeping
2013-04-30 16:14                         ` Jeff King
2013-05-05 15:40         ` Pete Wyckoff [this message]

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