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Subject: Re: IPC lock patch performance improvement
To: Hugh Dickins <hugh@veritas.com>
Cc: linux-kernel@vger.kernel.org, <lse-tech@lists.sourceforge.net>,
       "Mingming Cao" <mcao@us.ibm.com>, "Bill Hartner" <bhartner@us.ibm.com>
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From: "Duc Vianney" <dvianney@us.ibm.com>
Date: Thu, 8 Aug 2002 12:08:07 -0500
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>Please show me I'm wrong, but so far as I can see (from source and
>breakpoints) LMbench never touches the SysV IPC code, which is the only
>code affected by Mingming's proposed IPC locking changes.  I believe
>LMbench tests InterProcessCommunication via pipes and sockets,
>not via the SysV IPC msg sem and shm.

Your observation was correct.

LMbench tests Interprocess communication using pipes and sockets.
Mingming Cao's IPC lock patch was not touched by LMbench.

The reason for the performance gain when applying the patch is not
yet clear and under investigation. I will share my analysis once it
is completed. I do realize that there is a variance in the data
generated by LMbench.

Duc.





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