From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with ESMTP id 36C766B005A for ; Fri, 12 Jun 2009 03:52:58 -0400 (EDT) Date: Fri, 12 Jun 2009 09:54:27 +0200 From: Nick Piggin Subject: Re: slab: setup allocators earlier in the boot sequence Message-ID: <20090612075427.GA24044@wotan.suse.de> References: <200906111959.n5BJxFj9021205@hera.kernel.org> <1244770230.7172.4.camel@pasglop> <1244779009.7172.52.camel@pasglop> <1244780756.7172.58.camel@pasglop> <1244783235.7172.61.camel@pasglop> <1244792079.7172.74.camel@pasglop> <1244792745.30512.13.camel@penberg-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1244792745.30512.13.camel@penberg-laptop> Sender: owner-linux-mm@kvack.org To: Pekka Enberg Cc: Benjamin Herrenschmidt , Linus Torvalds , Linux Kernel list , linux-mm , mingo@elte.hu, cl@linux-foundation.org, akpm@linux-foundation.org List-ID: On Fri, Jun 12, 2009 at 10:45:45AM +0300, Pekka Enberg wrote: > On Fri, 2009-06-12 at 17:34 +1000, Benjamin Herrenschmidt wrote: > > I really believe this should be a slab internal thing, which is what my > > patch does to a certain extent. IE. All callers need to care about is > > KERNEL vs. ATOMIC and in some cases, NOIO or similar for filesystems > > etc... but I don't think all sorts of kernel subsystems, because they > > can be called early during boot, need to suddenly use GFP_NOWAIT all the > > time. > > > > That's why I much prefer my approach :-) (In addition to the fact that > > it provides the basis for also fixing suspend/resume). > > Sure, I think we can do what you want with the patch below. I don't really like adding branches to slab allocator like this. init code all needs to know what services are available, and this includes the scheduler if it wants to do anything sleeping (including sleeping slab allocations). Core mm code is the last place to put in workarounds for broken callers... > > But I still think we need my patch regardless. The call sites I > converted are all init code and should be using GFP_NOWAIT. Does it fix > your boot on powerpc? > > Pekka > > diff --git a/mm/slab.c b/mm/slab.c > index 9a90b00..722beb5 100644 > --- a/mm/slab.c > +++ b/mm/slab.c > @@ -2791,6 +2791,13 @@ static int cache_grow(struct kmem_cache *cachep, > > offset *= cachep->colour_off; > > + /* > + * Lets not wait if we're booting up or suspending even if the user > + * asks for it. > + */ > + if (system_state != SYSTEM_RUNNING) > + local_flags &= ~__GFP_WAIT; > + > if (local_flags & __GFP_WAIT) > local_irq_enable(); > > diff --git a/mm/slub.c b/mm/slub.c > index 65ffda5..f9a6bc8 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -1547,6 +1547,13 @@ new_slab: > goto load_freelist; > } > > + /* > + * Lets not wait if we're booting up or suspending even if the user > + * asks for it. > + */ > + if (system_state != SYSTEM_RUNNING) > + gfpflags &= ~__GFP_WAIT; > + > if (gfpflags & __GFP_WAIT) > local_irq_enable(); > > -- 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