On Thu, May 15, 2008 at 10:42:15AM -0700, Christoph Lameter wrote: > On Mon, 12 May 2008, David Chinner wrote: > > > If you are going to clean bufferheads (or pages), please clean entire > > mappings via ->writepages as it leads to far superior I/O patterns > > and a far higher aggregate rate of page cleaning..... > > That brings up another issue: Lets say I use writepages on a large file > (couple of gig). How much do you want to write back? We're out of memory. I'd suggest write backing as much as you can without blocking. e.g. treat it like pdflush and say 1024 pages, or like balance_dirty_pages() and write a 'write_chunk' back from the mapping (i.e. sync_writeback_pages()). Any of these are better from an I/O perspective than single page writeback.... Cheers, Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
