Ted Ts'o wrote: > On Mon, Nov 29, 2010 at 02:16:02PM +0100, Raphael Hertzog wrote:
>> It means we don't need to keep it in RAM since we're not going to >> read/modifiy it again in the near future. Thus the writeback can be >> started right now since delaying it will not save us anything. >> >> At least that's the way I understand the situation. > > Yes, that's correct. The fadvise() will do two things; it will start > the writeback, and also make these memory pages be the most likely to > be discarded. That explanation helps a lot. Thanks, both. (Guillem, I like your patch very much then. Most files being unpacked in a dpkg run aren't going to be read back again soon. Perhaps some other kernels will also interpret it as a hint to start writeback.) > The reason why I suggested using sync_file_range() is because it is > very specifically directed at forcing the writeback to happen, which > is not quite the same thrust as posix_fadvise(). I suppose a patch to adopt the optimization you suggested ought to also do the sync_file_range() directly to be explicit. -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
