Re: CVS commit: src/lib/libc/sys

[yamt%mwd.biglobe.ne.jp@localhost (YAMAMOTO Takashi)]

hi,

> On Tue, Jun 09, 2009 at 11:21:34AM +0000, YAMAMOTO Takashi wrote:
>> Log Message:
>> don't bother to say that some advises are not implemented.
>> ignoring them is a valid implementation.
> 
> It should not be under BUGS, but it should still be documented.
> E.g. POSIX_FADV_NOREUSE would be very helpful for things like tar and cp
> to reduce buffer cache pressure.
> 
> Joerg

i want to implement them if useful.
do you have any idea what an implementation of POSIX_FADV_NOREUSE
which is not a no-op would be like?

IMO, the use-once stream is a too common workload to require
an explicit hint.  the VM should just handle it nicely without hints.
i have to admit that i have no idea what NOREUSE hint can optimize it
further.

YAMAMOTO Takashi