Horton

Re: profiling connection overhead

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Peter Eisentraut <peter_e@gmx.net>
Cc: Jeff Janes <jeff.janes@gmail.com>, Andres Freund <andres@anarazel.de>, Robert Haas <robertmhaas@gmail.com>, Bruce Momjian <bruce@momjian.us>, pgsql-hackers@postgresql.org, Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
Date: 2010-11-30T20:49:07Z
Lists: pgsql-hackers 
Peter Eisentraut <peter_e@gmx.net> writes:
> On mn, 2010-11-29 at 13:10 -0500, Tom Lane wrote:
>> Rolling in calloc in place of
>> malloc/memset made no particular difference either, which says that
>> Fedora 13's glibc does not have any optimization for that case as I'd
>> hoped.

> glibc's calloc is either mmap of /dev/zero or malloc followed by memset.

Hmm.  I would have expected to see a difference then.  Do you know what
conditions are needed to cause the mmap to be used?

			regards, tom lane