Re: MAP_SHARED bizarrely slow

From: James Cloos
Date: Wed Oct 27 2004 - 02:26:43 EST


>>>>> "David" == David Gibson <david@xxxxxxxxxxxxxxxxxxxxx> writes:

David> http://www.ozlabs.org/people/dgibson/maptest.tar.gz

David> On a number of machines I've tested - both ppc64 and x86 - the
David> SHARED version is consistently and significantly (50-100%)
David> slower than the PRIVATE version.

Just gave it a test on my laptop and server. Both are p3. The
laptop is under heavier mem pressure; the server has just under
a gig with most free/cache/buff. Laptop is still running 2.6.7
whereas the server is bk as of 2004-10-24.

Buth took about 11 seconds for the private and around 30 seconds
for the shared tests.

So if this is a regression, it predates v2.6.7.

-JimC
--
James H. Cloos, Jr. <cloos@xxxxxxxxxxx> <http://jhcloos.com>


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