From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nikita Danilov MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <16416.62172.489558.39126@laputa.namesys.com> Date: Wed, 4 Feb 2004 16:25:48 +0300 Subject: Re: [PATCH 0/5] mm improvements In-Reply-To: <4020BDCB.8030707@cyberone.com.au> References: <4020BDCB.8030707@cyberone.com.au> Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: Andrew Morton , linux-mm@kvack.org List-ID: Nick Piggin writes: > Patches against 2.6.2-rc3-mm1. > Please test / review / comment. Hello, Nick, I composed a new patch that may be worth trying: ftp://ftp.namesys.com/pub/misc-patches/unsupported/extra/2004.02.04/p12-dont-unmap-on-pageout.patch It avoids (if possible) unmapping dirty page before calling ->writepage(). Intention is to avoid minor page faults for the pages under write-back. To this end new function mm/rmap.c:page_is_dirty() is added that scans page's ptes and transfers their dirtiness to the struct page itself. page_is_dirty() is called by shrink_list() and page is unmapped only if page_is_dirty() found all ptes clean. Few points: 1. I only gave it light testing (compared with other patches in the "extra" series). 2. dont-unmap-on-pageout logically depends on check-pte-dirty, and textually on skip-writepage patches. 3. for some unimportant reasons patches were produces with "diff -b", and may, hence, require "patch -l" to apply. 4. I found that shmem_writepage() has BUG_ON(page_mapped(page)) check. Its removal had no effect, and I am not sure why the check was there at all. Nikita. -- 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-mm.org/ . Don't email: aart@kvack.org