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Date: Sat, 14 Nov 2015 01:24:18 +0100
Message-ID: <CABPLASTtRK4mNxh0M_AnZgjJQ15kWPx+L=U=VCU3Wwi7jV_57A@mail.gmail.com>
Subject: Cygwin multithreading performance
From: Kacper Michajlow <kasper93@gmail.com>
To: cygwin@cygwin.com
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Hello,

I recently noticed that Cygwin multithreading is very inefficient. I
was repacking few git repositories and with Cygwin's git, it spawns
threads but they are so badly synchronized that there is no speed gain
over one thread and possible loose because of the overhead. On my
machine I got 7-10% CPU usage while with git build with mingw easily
uses 100%.

You can find the code in question here
https://github.com/git/git/blob/master/builtin/pack-objects.c#L1967-L2094

Do you have any suggestions? Is there any chance to get MT workloads
improved in Cygwin? In present days it is really big problem in my
opinion.

Best Regard

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