From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750816AbVHGDwh (ORCPT ); Sat, 6 Aug 2005 23:52:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750819AbVHGDwh (ORCPT ); Sat, 6 Aug 2005 23:52:37 -0400 Received: from rwcrmhc12.comcast.net ([216.148.227.85]:5812 "EHLO rwcrmhc12.comcast.net") by vger.kernel.org with ESMTP id S1750816AbVHGDwh (ORCPT ); Sat, 6 Aug 2005 23:52:37 -0400 Subject: overcommit verses MAP_NORESERVE From: Nicholas Miell To: linux-kernel@vger.kernel.org Content-Type: text/plain Date: Sat, 06 Aug 2005 20:52:35 -0700 Message-Id: <1123386755.26540.9.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.2.2 (2.2.2-8.njm.2) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Why does overcommit in mode 2 (OVERCOMMIT_NEVER) explicitly force MAP_NORESERVE mappings to reserve memory? My understanding is that MAP_NORESERVE is a way for apps to state that they are aware that the memory allocated may not exist and that they might get a SIGSEGV and that's OK with them. Failing to do this makes certain well-know apps (*cough* Sun Java *cough*) fail to run, which seems to be rather unhelpful. -- Nicholas Miell