On Mon, Oct 31, 2011 at 11:16:59AM -0500, Shawn Bohrer wrote: > Previously POSIX_FADV_DONTNEED would start writeback for the entire file > when the bdi was not write congested. This negatively impacts > performance if the file contians dirty pages outside of the requested > range. This change uses __filemap_fdatawrite_range() to only initiate > writeback for the requested range. > > Signed-off-by: Shawn Bohrer <sbohrer@xxxxxxxxxxxxxxx> It probably makes sense for some cases to take advantage of the disk head being nearby and flush more than requested. But I can certainly see this go wrong by taking away the write-caching benefits for the rest of the file just because a small part of it was fadvised. Acked-by: Johannes Weiner <jweiner@xxxxxxxxxx> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>