2010/9/12 Jeff Layton <jlayton@xxxxxxxxx>: > write_begin/write_end are called on each page in a write syscall. So if > your application is writing in 64k page-aligned chunks, write_end will > be called 16 times. When you have no oplock with this patch, for each > call to write_end, you're calling cifs_write which will flush each > single page synchronously and only that single page to the server. Your > 64k write will take 16 round trips to the server to complete. > > What you probably want to do instead is populate the pagecache with the > write contents (as is done today), flush the write and wait on the > result. Optionally, you could then invalidate the cache to free up the > pagecache pages (though you'll need to take care not to race with other > writers). Ok, I understand you. What do you think about the following idea? 1) if we don't have an exclusive oplock, we write the data to the server before do_sync_write but in cifs_write_end we don't mark the page as dirty and don't write to the server; 2) if we have an exclusive oplock, we don't write the data before do_sync_write and mark page as dirty in cifs_write_end (again we don't write anything to the server in cifs_write_end); -- Best regards, Pavel Shilovsky. -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
