From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 22 Dec 1999 10:08:11 -0500 (EST) From: Chuck Lever Subject: Re: [patch] mmap<->write deadlock fix, plus bug in block_write_zero_range In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: "Benjamin C.R. LaHaise" Cc: Linus Torvalds , linux-mm@kvack.org List-ID: On Wed, 22 Dec 1999, Benjamin C.R. LaHaise wrote: > The patch to filemap.c changes filemap_nopage to use __find_page_nolock > rather than __find_get_page which waits for the page to become unlocked > before returning (maybe __find_get_page was meant to check PageUptodate?), > since filemap_nopage checks PageUptodate before proceeding -- which is > consistent with do_generic_file_read. i've tried this before several times. i could never get the system to perform as well under benchmark load using find_page_nolock as when using find_get_page. the throughput difference was about 5%, if i recall. i haven't explained this to myself yet. perhaps a better fix would be to take out some of the page lock complexity from filemap_nopage? dunno. - Chuck Lever -- corporate: personal: or The Linux Scalability project: http://www.citi.umich.edu/projects/linux-scalability/ -- 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.nl.linux.org/Linux-MM/