From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-f173.google.com (mail-ob0-f173.google.com [209.85.214.173]) by kanga.kvack.org (Postfix) with ESMTP id CBC176B0062 for ; Tue, 1 Apr 2014 17:13:11 -0400 (EDT) Received: by mail-ob0-f173.google.com with SMTP id gq1so11807125obb.32 for ; Tue, 01 Apr 2014 14:13:11 -0700 (PDT) Received: from mail-oa0-x235.google.com (mail-oa0-x235.google.com [2607:f8b0:4003:c02::235]) by mx.google.com with ESMTPS id a1si12978695oed.71.2014.04.01.14.13.10 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 01 Apr 2014 14:13:11 -0700 (PDT) Received: by mail-oa0-f53.google.com with SMTP id j17so11711426oag.26 for ; Tue, 01 Apr 2014 14:13:10 -0700 (PDT) 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 Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Davidlohr Bueso Cc: Andrew Morton , Manfred Spraul , aswin@hp.com, LKML , "linux-mm@kvack.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, 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