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Date: Sat, 18 May 2013 13:59:15 +0200
From: Florent Peterschmitt <florent@peterschmitt.fr>
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Subject: Re: blogbench and write-open serialization
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Le 18/05/2013 06:04, Ivan Voras a écrit :
> During the BSDCan & DevSummit I got interested in finding out why
> blogbench is so slow on FreeBSD. After talking to jhb, it looked like
> one of the reasons might be that opening files with O_RDWR or O_WRONLY
> (anything opening the file for writing) is serialized.
>
> To check this, I've written a small test program, which I've run on
> CentOS 6.3 and FreeBSD 10-HEAD on the same hardware. Here are the results:
>
> https://wiki.freebsd.org/Benchmarking/OpenCloseBenchmark
>
> Conclusions:
>
> * Linux opens and closes files much faster than FreeBSD
> * Linux does not serialize write-open operations, while FreeBSD does
> * Even with O_RDONLY, FreeBSD is much slower in opening (and closing) files.
>
> I'd welcome a review of these results and comments.

Hi,

I'm no able to say anything about that (because I've no idea of how does 
Linux or FreeBSD works ), but could it be a problem from filesystem ?

Everytime I had UFS I found the entire system very slow when doing some 
I/O (many little freezes), and with ZFS it's globally much better.