From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f48.google.com (mail-pa0-f48.google.com [209.85.220.48]) by kanga.kvack.org (Postfix) with ESMTP id D94216B0036 for ; Tue, 27 May 2014 18:01:02 -0400 (EDT) Received: by mail-pa0-f48.google.com with SMTP id rd3so9860086pab.35 for ; Tue, 27 May 2014 15:01:02 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTP id ns7si20473429pbb.248.2014.05.27.15.01.01 for ; Tue, 27 May 2014 15:01:02 -0700 (PDT) Date: Tue, 27 May 2014 15:01:00 -0700 From: Andrew Morton Subject: Re: [PATCH mmotm/next] memcg-mm-introduce-lowlimit-reclaim-fix2.patch Message-Id: <20140527150100.70f6c7cf93d27d58c8f5eb48@linux-foundation.org> In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Hugh Dickins Cc: Michal Hocko , Johannes Weiner , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Tue, 27 May 2014 14:36:04 -0700 (PDT) Hugh Dickins wrote: > mem_cgroup_within_guarantee() oopses in _raw_spin_lock_irqsave() when > booted with cgroup_disable=memory. Fix that in the obvious inelegant > way for now - though I hope we are moving towards a world in which > almost all of the mem_cgroup_disabled() tests will vanish, with a > root_mem_cgroup which can handle the basics even when disabled. > > I bet there's a neater way of doing this, rearranging the loop (and we > shall want to avoid spinlocking on root_mem_cgroup when we reach that > new world), but that's the kind of thing I'd get wrong in a hurry! > > ... > > @@ -2793,6 +2793,9 @@ static struct mem_cgroup *mem_cgroup_loo > bool mem_cgroup_within_guarantee(struct mem_cgroup *memcg, > struct mem_cgroup *root) > { > + if (mem_cgroup_disabled()) > + return false; > + > do { > if (!res_counter_low_limit_excess(&memcg->res)) > return true; This seems to be an awfully late and deep place at which to be noticing mem_cgroup_disabled(). Should mem_cgroup_within_guarantee() even be called in this state? -- 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