Re: Linux disk performance.

["Manish Regmi" <regmi.manish@gmail.com>]

On 12/18/06, Arjan van de Ven <arjan@infradead.org> wrote:
> if you want truely really smooth writes you'll have to work for it,
> since "bumpy" writes tend to be better for performance so naturally the
> kernel will favor those.
>
> to get smooth writes you'll need to do a threaded setup where you do an
> msync/fdatasync/sync_file_range on a frequent-but-regular interval from
> a thread. Be aware that this is quite likely to give you lower maximum
> performance than the batching behavior though.
>

Thanks...

But isn't O_DIRECT supposed to bypass buffering in Kernel?
Doesn't it directly write to disk?
I tried to put fdatasync() at regular intervals but there was no
visible effect.

-- 
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regards
Manish Regmi

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UNIX without a C Compiler is like eating Spaghetti with your mouth
sewn shut. It just doesn't make sense.