From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH next 1/3] slub defrag: unpin writeback pages From: Pekka Enberg In-Reply-To: References: Date: Mon, 06 Oct 2008 10:53:12 +0300 Message-Id: <1223279592.30581.4.camel@penberg-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Hugh Dickins Cc: Christoph Lameter , Andrew Morton , linux-mm@kvack.org List-ID: On Sun, 2008-10-05 at 03:25 +0100, Hugh Dickins wrote: > A repetitive swapping load on powerpc G5 went progressively slower after > nine hours: Inactive(file) was rising, as if inactive file pages pinned. > Yes, slub defrag's kick_buffers() was forgetting to put_page() whenever > it met a page already under writeback. > > That PageWriteback test should be made while PageLocked in trigger_write(), > just as it is in try_to_free_buffers() - if there are complex reasons why > that's not actually necessary, I'd rather not have to think through them. > A preliminary check before taking the lock? No, it's not that important. > > And trigger_write() must remember to unlock_page() in each of the cases > where it doesn't reach the writepage(). > > Signed-off-by: Hugh Dickins Looks good to me. I've applied the patch now but would really like an ACK from Christoph/Andrew as well. Thanks again, Hugh! Pekka -- 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: email@kvack.org