Re: MySQL Performance 6.0rc1

From: Poul-Henning Kamp <phk_at_phk.freebsd.dk>
Date: Thu, 27 Oct 2005 10:20:20 +0200
In message <43607DD5.3020708_at_freebsd.org>, David Xu writes:

>Check gettimeofday syscall, it follows every I/O syscall, I think
>our gettimeofday is tooooooo expensive, if we can directly get time from
>memory, the performance will be improved further.

Why would anybody take a timestamp at all I/O syscalls ? 

"I wonder why my car can only go 30 km/h with the trunk full of concrete" ?

In a data base application I could possibly understand a timestamp
after every write.

But after _all_ I/O syscalls ?  That's just plain stupid...

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk_at_FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.
Received on Thu Oct 27 2005 - 06:20:24 UTC

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