[erlang-questions] Linux O_DIRECT flag

[Rapsey]

I don't understand. Why is that a problem? Access to RAM will always be much
faster than access to a storage array.


On Fri, Mar 14, 2008 at 8:45 PM, Valentin Micic <valentin@REDACTED>
wrote:

> Dear all,
>
> One thing that has to make a top 10 most-likely-to-frustrate-you features
> in
> LINUX is its uncontrollable usage of memory for I/O caching. Whilst good
> for
> most applications, it seems quite redundant if you connect a big storage
> array that has a cache on its own.
> After a brief investigation regarding ones ability to bypass the cache
> (performed by our hardware supplier), I've been told that an application
> may
> bypass the cache by porviding additional flag to "open" system call --
> O_DIRECT to be more specific. I assume that file:open/2 does not support
> this flag, so I'd like to ask, before we start hacking around:  is there
> an
> easy way to expose this flag, and would you consider it for inclusion in
> one
> of the next releases. Provided that O_DIRECT does what we think it does,
> of
> course.
>
> Thanks in advance,
>
> Valenitn.
>
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