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List:       hpux-devtools
Subject:    Re: HPUX-DEVTOOLS: =?gb2312?B?tPC4tDogIEhQVVgtREVWVE9PTFM6IFJFOiBtbWFwIHBlcmZvcm1hbmNl?=
From:       Kapil Chowksey <kchowkse () in ! ibm ! com>
Date:       2008-03-07 8:37:26
Message-ID: 18384.64502.709146.545832 () kchowkse ! india ! rational ! com
[Download RAW message or body]

On Friday, 7 March, Chen, Yan-Ke (TSG-SMO-ChannelSupport-BJ) wrote:

> Now I tested the program in hp-ux11.31, and the performance is also poor. If I have \
> another process mmap the file and never exist, the performance is perfect(same as \
> share mermory). From the test result, I think munmap is async in Solaris/Linux, but \
> it's sync in hpux.

One simple way to increase the performance is to have a another
process which mmaps(MAP_SHARED) the entire file and goes to sleep.

This way, when your first process munmap()s, there is still a
reference held to these pages and they don't get flushed to the
backing store.

11.31 with single process:
real        4.03
user        0.01
sys         0.11

11.31 with another process holding a reference:
real        0.01
user        0.00
sys         0.01

This method will help you only on 11.31


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