[Fontconfig] [PATCH 1/2] Use MAP_POPULATE to eliminate startup page faults.

[Keith Packard]

On Thu, 31 Dec 2009 21:54:10 +0100, Behdad Esfahbod <behdad at behdad.org> wrote:

> The mmap manpage says: MAP_POPULATE is  only  supported  for private mappings 
> since Linux 2.6.23.  Does the POPULATE do anything with MAP_SHARED?

Hrm. I recall measuring this a while ago and finding some difference in
the page fault counts, but I cannot replicate that now (even after
fixing my patch to not call mmap twice). I'd say you can discard this patch.

> An alternative would be calling fadvise().

This also has no effect:

     posix_fadvise(fd, 0, fd_stat->st_size, POSIX_FADV_WILLNEED))

Looks like whatever effect I measured has disappeared in more recent
kernels.

-- 
keith.packard at intel.com
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