From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 6 Feb 2001 10:39:23 -0200 (BRST) From: Marcelo Tosatti Subject: Re: [PATCH] thinko in mm/filemap.c (242p1) In-Reply-To: <20010206135857.J18574@jaquet.dk> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Rasmus Andersen Cc: Rik van Riel , linux-mm@kvack.org List-ID: On Tue, 6 Feb 2001, Rasmus Andersen wrote: > On Tue, Feb 06, 2001 at 10:51:05AM -0200, Rik van Riel wrote: > > On Tue, 6 Feb 2001, Rasmus Andersen wrote: > [...] > > > > I guess the writeout_one_page schedules the dirty pages for IO > > and puts them on the list of locked pages. The last call then > > waits on those same pages until they've been flushed to disk. > > > > Your change would wait on the pages but never submit them for > > IO (again, a guess, I haven't looked at the code in too much > > detail). > > The total function (generic_buffer_fdatasync) (with my patch): > > /* writeout dirty buffers on pages from both clean and dirty lists */ > retval = do_buffer_fdatasync(&inode->i_mapping->dirty_pages, start_idx, > end_idx, writeout_one_page); > retval |= do_buffer_fdatasync(&inode->i_mapping->clean_pages, start_idx, > end_idx, writeout_one_page); > retval |= do_buffer_fdatasync(&inode->i_mapping->locked_pages, start_idx > , end_idx, writeout_one_page); > > /* now wait for locked buffers on pages from both clean and dirty lists > */ > retval |= do_buffer_fdatasync(&inode->i_mapping->dirty_pages, start_idx, > end_idx, waitfor_one_page); > retval |= do_buffer_fdatasync(&inode->i_mapping->clean_pages, start_idx, > end_idx, waitfor_one_page); > retval |= do_buffer_fdatasync(&inode->i_mapping->locked_pages, start_idx > , end_idx, waitfor_one_page); > > > So we start the writeout in the three first lines and wait for them in > the last three. Without my patch we write dirty_pages out again in the > second run. Pages written in the first run will be moved to the locked list. No big deal, but its not a critical bug right now. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux.eu.org/Linux-MM/