On Friday, March 16, 2012 04:47:06 PM Robert Haas wrote: > On Fri, Mar 16, 2012 at 6:25 AM, Andres Freund <and...@anarazel.de> wrote: > >> > How are the results with sync_file_range(fd, 0, 0, > >> > SYNC_FILE_RANGE_WRITE)? > >> > >> That is much faster than using fadvise. It goes down to ~2s. > >> > >> Unfortunately, that's non-portable. Any other ideas? 6.5s a little on > >> the annoying side (and causes some disconcerting sounds to come from my > >> disk), especially when we _know_ it can be done in 2s. > > > > Its not like posix_fadvise is actually portable. So I personally don't > > see a problem with that, but... > > Well, sync_file_range only works on Linux, and will probably never > work anywhere else. posix_fadvise() at least has a chance of being > supported on other platforms, being a standard and all that. Though I > see that my Mac has neither. :-( I would suggest adding a wrapper function like: pg_hint_writeback_flush(fd, off, len);
which then is something like #if HAVE_SYNC_FILE_RANGE sync_file_range(fd, off, len, SYNC_FILE_RANGE_WRITE); #elseif HAVE_POSIX_FADVISE posix_fadvise(fd, off, len, POSIX_FADV_DONTNEED); #else #endif To my knowledge posix_fadvise currently is only supported on linux btw... Andres -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
