madvise() vs posix_fadvise()

[Dmitry Sivachenko]

On 03 апр. 2014 г., at 20:30, John Baldwin <jhb at FreeBSD.org> wrote:

> 
> The latter.  It's sort of like a lazy O_DIRECT.  Each time you call write(2),
> it tries to move any clean pages from your current sequentially written
> stream from inactive to cache, so the pages won't move until a subsequent
> write(2) after bufdaemon or the syncer actually forces them to be written.
> Unfortunately, it is currently implemented by doing an internal
> FADV_DONTNEED after each read() or write().  It would be better if it was
> implemented as a callback when buffers are completed.



Sounds like FADV_NOREUSE should be befeficial for any log-writing program? (syslogd, apache, nginx, .....)