Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261234AbUKICXs (ORCPT ); Mon, 8 Nov 2004 21:23:48 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261351AbUKICXs (ORCPT ); Mon, 8 Nov 2004 21:23:48 -0500 Received: from mail-01.iinet.net.au ([203.59.3.33]:60106 "HELO mail.iinet.net.au") by vger.kernel.org with SMTP id S261234AbUKICXd (ORCPT ); Mon, 8 Nov 2004 21:23:33 -0500 Message-ID: <419029D9.90506@cyberone.com.au> Date: Tue, 09 Nov 2004 13:22:17 +1100 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.2) Gecko/20040820 Debian/1.7.2-4 X-Accept-Language: en MIME-Version: 1.0 To: Marcelo Tosatti CC: Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [PATCH] Remove OOM killer from try_to_free_pages / all_unreclaimable braindamage References: <20041105200118.GA20321@logos.cnet> <20041108162731.GE2336@logos.cnet> <20041108185546.GA3468@logos.cnet> In-Reply-To: <20041108185546.GA3468@logos.cnet> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1591 Lines: 47 Marcelo Tosatti wrote: >On Mon, Nov 08, 2004 at 02:27:31PM -0200, Marcelo Tosatti wrote: > >>On Fri, Nov 05, 2004 at 06:01:18PM -0200, Marcelo Tosatti wrote: >> >> >>>While doing this, I noticed that kswapd will happily go to sleep >>>if all zones have all_unreclaimable set. I bet this is the reason >>>for the page allocation failures we are seeing. So the patch >>>also makes balance_pgdat() NOT return and go to "loop_again" >>>instead in case of page shortage - even if all_unreclaimable is set. >>> >>>Basically the "loop_again" logic IS NOT WORKING! >>> >>Wrong, the loop_again logic is working, all_zones_ok will be >>set when DEF_PRIORITY = 0. >> > >I meant priority=DEF_PRIORITY. > > Yep >>So the page allocation failures are happening for some other >>reason(s). >> Pre alloc_pages / kswapd shakeup, the watermark stuff had been pretty broken. For example, allocations would wakeup kswapd at the *same* watermark as they would start synchronous reclaim (or fail in the case of !wait allocations). Why there have been apparently more reports of allocation failures since those patches is a mystery to me. I've looked but can't find anything to explain it. Perhaps the initial watermark calculation had been changed slightly? I'm not sure... it could also be just be a fluke due to chaotic effects in the mm, I suppose :| - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/