Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753171Ab3CFRIn (ORCPT ); Wed, 6 Mar 2013 12:08:43 -0500 Received: from mail-ie0-f180.google.com ([209.85.223.180]:51644 "EHLO mail-ie0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751742Ab3CFRIm (ORCPT ); Wed, 6 Mar 2013 12:08:42 -0500 Date: Tue, 5 Mar 2013 19:37:27 -0500 From: Andrew Shewmaker To: Simon Jeons Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, alan@lxorguk.ukuu.org.uk, ric.masonn@gmail.com Subject: Re: [PATCH v4 001/002] mm: limit growth of 3% hardcoded other user reserve Message-ID: <20130306003727.GA2072@localhost.localdomain> References: <20130305233811.GA1948@localhost.localdomain> <513683D5.1080401@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <513683D5.1080401@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3059 Lines: 86 On Wed, Mar 06, 2013 at 07:46:29AM +0800, Simon Jeons wrote: > On 03/06/2013 07:38 AM, Andrew Shewmaker wrote: > >Limit the growth of the memory reserved for other processes > >to the smaller of 3% or 8MB. > > > >This affects only OVERCOMMIT_NEVER. > > > >Signed-off-by: Andrew Shewmaker > > Please add changelog, otherwise it's for other guys to review. > Sorry, I'll be sure to include one in the future. And it looks like I do need a v5 ... I think this needs to be tunable like the admin reserve. The default certainly needs to be higher since this reserve is only for OVERCOMMIT_NEVER mode and 8MB is too little to allow the user to recover. I was thinking of OVERCOMMIT_GUESS mode when I chose it. v4: * Rebased onto v3.8-mmotm-2013-03-01-15-50 * No longer assumes 4kb pages * Code duplicated for nommu v3: * New patch summary because it wasn't unique New is "mm: limit growth of 3% hardcoded other user reserve" Old was "mm: tuning hardcoded reserve memory" * Limits growth to min(3% process size, some constant k) as Alan Cox suggested. I chose k=2000 pages (8MB) to allow recovery with sshd or login, bash, and top or kill v2: * Rebased onto v3.8-mmotm-2013-02-19-17-20 v1: * Based on 3.8 * Remove hardcoded 3% other user reserve in OVERCOMMIT_NEVER mode > > > >--- > > > >Rebased onto v3.8-mmotm-2013-03-01-15-50 > > > >No longer assumes 4kb pages. > >Code duplicated for nommu. > > > >diff --git a/mm/mmap.c b/mm/mmap.c > >index 49dc7d5..4eb2b1a 100644 > >--- a/mm/mmap.c > >+++ b/mm/mmap.c > >@@ -184,9 +184,11 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) > > allowed += total_swap_pages; > > /* Don't let a single process grow too big: > >- leave 3% of the size of this process for other processes */ > >+ * leave the smaller of 3% of the size of this process > >+ * or 8MB for other processes > >+ */ > > if (mm) > >- allowed -= mm->total_vm / 32; > >+ allowed -= min(mm->total_vm / 32, 1 << (23 - PAGE_SHIFT)); > > if (percpu_counter_read_positive(&vm_committed_as) < allowed) > > return 0; > >diff --git a/mm/nommu.c b/mm/nommu.c > >index f5d57a3..a93d214 100644 > >--- a/mm/nommu.c > >+++ b/mm/nommu.c > >@@ -1945,9 +1945,11 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) > > allowed += total_swap_pages; > > /* Don't let a single process grow too big: > >- leave 3% of the size of this process for other processes */ > >+ * leave the smaller of 3% of the size of this process > >+ * or 8MB for other processes > >+ */ > > if (mm) > >- allowed -= mm->total_vm / 32; > >+ allowed -= min(mm->total_vm / 32, 1 << (23 - PAGE_SHIFT)); > > if (percpu_counter_read_positive(&vm_committed_as) < allowed) > > return 0; > -- 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/