From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f51.google.com (mail-pa0-f51.google.com [209.85.220.51]) by kanga.kvack.org (Postfix) with ESMTP id B352A6B00A6 for ; Tue, 5 Nov 2013 18:53:23 -0500 (EST) Received: by mail-pa0-f51.google.com with SMTP id ld10so9620869pab.38 for ; Tue, 05 Nov 2013 15:53:23 -0800 (PST) Received: from psmtp.com ([74.125.245.131]) by mx.google.com with SMTP id n5si15400161pav.156.2013.11.05.15.53.21 for ; Tue, 05 Nov 2013 15:53:22 -0800 (PST) Date: Tue, 5 Nov 2013 15:53:19 -0800 From: Andrew Morton Subject: Re: [PATCH v4 2/2] mm: allow to set overcommit ratio more precisely Message-Id: <20131105155319.732dcbefb162c2ee4716ef9d@linux-foundation.org> In-Reply-To: <1382101019-23563-2-git-send-email-jmarchan@redhat.com> References: <1382101019-23563-1-git-send-email-jmarchan@redhat.com> <1382101019-23563-2-git-send-email-jmarchan@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Jerome Marchand Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, dave.hansen@intel.com On Fri, 18 Oct 2013 14:56:59 +0200 Jerome Marchand wrote: > Some applications that run on HPC clusters are designed around the > availability of RAM and the overcommit ratio is fine tuned to get the > maximum usage of memory without swapping. With growing memory, the 1% > of all RAM grain provided by overcommit_ratio has become too coarse > for these workload (on a 2TB machine it represents no less than > 20GB). > > This patch adds the new overcommit_ratio_ppm sysctl variable that > allow to set overcommit ratio with a part per million precision. > The old overcommit_ratio variable can still be used to set and read > the ratio with a 1% precision. That way, overcommit_ratio interface > isn't broken in any way that I can imagine. The way we've permanently squished this mistake in the past is to switch to "bytes". See /proc/sys/vm/*bytes. Would that approach work in this case? -- 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