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Reply-To: moss@cs.umass.edu
Subject: Re: calloc speed difference
To: cygwin@cygwin.com
References: <CAD8GWsvxzFe0dPnxO-odTY+EG5XOAApLjcOSN5d7vXhtLW0GmQ@mail.gmail.com>
From: Eliot Moss <moss@cs.umass.edu>
Message-ID: <1f0f6e79-57ef-1f02-f673-81826948adfc@cs.umass.edu>
Date: Fri, 12 Jan 2018 03:38:20 -0500
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On 1/12/2018 2:19 AM, Lee wrote:
> Why is the cygwin gcc calloc so much slower than the
> i686-w64-mingw32-gcc calloc?

Since your test repeatedly allocates and frees one chunk
of size 100 Mb (ouch!) my guess is that the slow behavior is
rooted in something to do with mmap.  Perhaps Corinna
or another internals expert can explain why large mmap
requests would be a problem for cygwin -- and perhaps it
is something that could be improved if the effort is
warranted ...

Eliot Moss

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