From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f49.google.com (mail-wg0-f49.google.com [74.125.82.49]) by kanga.kvack.org (Postfix) with ESMTP id 760FA6B0038 for ; Mon, 7 Jul 2014 19:05:01 -0400 (EDT) Received: by mail-wg0-f49.google.com with SMTP id a1so1746697wgh.32 for ; Mon, 07 Jul 2014 16:05:00 -0700 (PDT) Received: from one.firstfloor.org (one.firstfloor.org. [193.170.194.197]) by mx.google.com with ESMTPS id n9si43195429wiz.23.2014.07.07.16.05.00 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Mon, 07 Jul 2014 16:05:00 -0700 (PDT) Date: Tue, 8 Jul 2014 01:04:59 +0200 From: Andi Kleen Subject: Re: fallout of 16K stacks Message-ID: <20140707230459.GF18735@two.firstfloor.org> References: <20140707223001.GD18735@two.firstfloor.org> <53BB240C.30400@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53BB240C.30400@zytor.com> Sender: owner-linux-mm@kvack.org List-ID: To: "H. Peter Anvin" Cc: Andi Kleen , torvalds@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Mon, Jul 07, 2014 at 03:49:48PM -0700, H. Peter Anvin wrote: > On 07/07/2014 03:30 PM, Andi Kleen wrote: > > > > Since the 16K stack change I noticed a number of problems with > > my usual stress tests. They have a tendency to bomb out > > because something cannot fork. > > As in ENOMEM or does something worse happen? EAGAIN, then the workload stops. For an overnight stress test that's pretty catastrophic. It may have killed some stuff with the OOM killer too. > > - AIM7 on a dual socket socket system now cannot reliably run > >> 1000 parallel jobs. > > ... with how much RAM? This system has 32G > > - LTP stress + memhog stress in parallel to something else > > usually doesn't survive the night. > > > > Do we need to strengthen the memory allocator to try > > harder for 16K? > > Can we even? The probability of success goes down exponentially in the > order requested. Movable pages can help, of course, but still, there is > a very real cost to this :( I hope so. In the worst case just try longer. -Andi -- ak@linux.intel.com -- Speaking for myself only. -- 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