Re: O_DIRECT please; Sybase 12.5

From: Andrea Arcangeli (
Date: Thu Jul 05 2001 - 08:59:42 EST

On Fri, Jun 29, 2001 at 10:50:15AM +0100, Alan Cox wrote:
> > the boss say "If Linux makes Sybase go through the page cache on
> > reads, maybe we'll just have to switch to Solaris. That's
> > a serious performance problem."
> Thats something you'd have to benchmark. It depends on a very large number
> of factors including whether the database uses mmap, the average I/O size
> and the like

correct, here the benchmarks:

of course the huge improvement is also because of broken VM in the
buffered-io case.

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This archive was generated by hypermail 2b29 : Sat Jul 07 2001 - 21:00:16 EST