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From: Jeff King <peff@peff.net>
To: Martin Fick <mfick@codeaurora.org>
Cc: Git Mailing List <git@vger.kernel.org>
Subject: Re: Resolving deltas dominates clone time
Date: Tue, 23 Apr 2019 00:21:09 -0400	[thread overview]
Message-ID: <20190423042109.GA19183@sigill.intra.peff.net> (raw)
In-Reply-To: <20190423015538.GA16369@sigill.intra.peff.net>

On Mon, Apr 22, 2019 at 09:55:38PM -0400, Jeff King wrote:

> Here are my p5302 numbers on linux.git, by the way.
> 
>   Test                                           jk/p5302-repeat-fix
>   ------------------------------------------------------------------
>   5302.2: index-pack 0 threads                   307.04(303.74+3.30)
>   5302.3: index-pack 1 thread                    309.74(306.13+3.56)
>   5302.4: index-pack 2 threads                   177.89(313.73+3.60)
>   5302.5: index-pack 4 threads                   117.14(344.07+4.29)
>   5302.6: index-pack 8 threads                   112.40(607.12+5.80)
>   5302.7: index-pack default number of threads   135.00(322.03+3.74)
> 
> which still imply that "4" is a win over "3" ("8" is slightly better
> still in wall-clock time, but the total CPU rises dramatically; that's
> probably because this is a quad-core with hyperthreading, so by that
> point we're just throttling down the CPUs).

And here's a similar test run on a 20-core Xeon w/ hyperthreading (I
tweaked the test to keep going after eight threads):

Test                            HEAD                
----------------------------------------------------
5302.2: index-pack 1 threads    376.88(364.50+11.52)
5302.3: index-pack 2 threads    228.13(371.21+17.86)
5302.4: index-pack 4 threads    151.41(387.06+21.12)
5302.5: index-pack 8 threads    113.68(413.40+25.80)
5302.6: index-pack 16 threads   100.60(511.85+37.53)
5302.7: index-pack 32 threads   94.43(623.82+45.70) 
5302.8: index-pack 40 threads   93.64(702.88+47.61) 

I don't think any of this is _particularly_ relevant to your case, but
it really seems to me that the default of capping at 3 threads is too
low.

-Peff

  reply	other threads:[~2019-04-23  4:21 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-19 21:47 Resolving deltas dominates clone time Martin Fick
2019-04-20  3:58 ` Jeff King
2019-04-20  7:59   ` Ævar Arnfjörð Bjarmason
2019-04-22 15:57     ` Jeff King
2019-04-22 18:01       ` Ævar Arnfjörð Bjarmason
2019-04-22 18:43         ` Jeff King
2019-04-23  7:07           ` Ævar Arnfjörð Bjarmason
2019-04-22 20:21   ` Martin Fick
2019-04-22 20:56     ` Jeff King
2019-04-22 21:02       ` Jeff King
2019-04-22 21:19       ` [PATCH] p5302: create the repo in each index-pack test Jeff King
2019-04-23  1:09         ` Junio C Hamano
2019-04-23  2:07           ` Jeff King
2019-04-23  2:27             ` Junio C Hamano
2019-04-23  2:36               ` Jeff King
2019-04-23  2:40                 ` Junio C Hamano
2019-04-22 22:32       ` Resolving deltas dominates clone time Martin Fick
2019-04-23  1:55         ` Jeff King
2019-04-23  4:21           ` Jeff King [this message]
2019-04-23 10:08             ` Duy Nguyen
2019-04-23 20:09               ` Martin Fick
2019-04-30 18:02                 ` Jeff King
2019-04-30 22:08                   ` Martin Fick
2019-04-30 17:50               ` Jeff King
2019-04-30 18:48                 ` Ævar Arnfjörð Bjarmason
2019-04-30 20:33                   ` Jeff King

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