Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751809AbaDAVNN (ORCPT ); Tue, 1 Apr 2014 17:13:13 -0400 Received: from mail-oa0-f41.google.com ([209.85.219.41]:57500 "EHLO mail-oa0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751354AbaDAVNL (ORCPT ); Tue, 1 Apr 2014 17:13:11 -0400 MIME-Version: 1.0 In-Reply-To: <1396386062.25314.24.camel@buesod1.americas.hpqcorp.net> References: <1396235199.2507.2.camel@buesod1.americas.hpqcorp.net> <20140331143217.c6ff958e1fd9944d78507418@linux-foundation.org> <1396306773.18499.22.camel@buesod1.americas.hpqcorp.net> <20140331161308.6510381345cb9a1b419d5ec0@linux-foundation.org> <1396308332.18499.25.camel@buesod1.americas.hpqcorp.net> <20140331170546.3b3e72f0.akpm@linux-foundation.org> <1396371699.25314.11.camel@buesod1.americas.hpqcorp.net> <1396377083.25314.17.camel@buesod1.americas.hpqcorp.net> <1396386062.25314.24.camel@buesod1.americas.hpqcorp.net> From: KOSAKI Motohiro Date: Tue, 1 Apr 2014 17:12:50 -0400 Message-ID: Subject: Re: [PATCH] ipc,shm: increase default size for shmmax To: Davidlohr Bueso Cc: Andrew Morton , Manfred Spraul , aswin@hp.com, LKML , "linux-mm@kvack.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 1, 2014 at 5:01 PM, Davidlohr Bueso wrote: > On Tue, 2014-04-01 at 15:51 -0400, KOSAKI Motohiro wrote: >> >> So, I personally like 0 byte per default. >> > >> > If by this you mean 0 bytes == unlimited, then I agree. It's less harsh >> > then removing it entirely. So instead of removing the limit we can just >> > set it by default to 0, and in newseg() if shm_ctlmax == 0 then we don't >> > return EINVAL if the passed size is great (obviously), otherwise, if the >> > user _explicitly_ set it via sysctl then we respect that. Andrew, do you >> > agree with this? If so I'll send a patch. >> >> Yes, my 0 bytes mean unlimited. I totally agree we shouldn't remove the knob >> entirely. > > Hmmm so 0 won't really work because it could be weirdly used to disable > shm altogether... we cannot go to some negative value either since we're > dealing with unsigned, and cutting the range in half could also hurt > users that set the limit above that. So I was thinking of simply setting > SHMMAX to ULONG_MAX and be done with it. Users can then set it manually > if they want a smaller value. > > Makes sense? I don't think people use 0 for disabling. but ULONG_MAX make sense to me too. -- 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/