From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f178.google.com (mail-pd0-f178.google.com [209.85.192.178]) by kanga.kvack.org (Postfix) with ESMTP id A714F6B006C for ; Tue, 28 Apr 2015 09:41:37 -0400 (EDT) Received: by pdbqa5 with SMTP id qa5so164322157pdb.1 for ; Tue, 28 Apr 2015 06:41:37 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id gy10si24455150pbd.243.2015.04.28.06.41.36 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 28 Apr 2015 06:41:36 -0700 (PDT) Date: Tue, 28 Apr 2015 06:48:10 -0700 From: Andrew Morton Subject: Re: [PATCH 07/13] mm: meminit: Initialise a subset of struct pages if CONFIG_DEFERRED_STRUCT_PAGE_INIT is set Message-Id: <20150428064810.0882ad36.akpm@linux-foundation.org> In-Reply-To: <20150428095323.GK2449@suse.de> References: <1429785196-7668-1-git-send-email-mgorman@suse.de> <1429785196-7668-8-git-send-email-mgorman@suse.de> <20150427154344.421fd9f151bf27d365d02fd2@linux-foundation.org> <20150428095323.GK2449@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Linux-MM , Nathan Zimmer , Dave Hansen , Waiman Long , Scott Norton , Daniel J Blueman , LKML On Tue, 28 Apr 2015 10:53:23 +0100 Mel Gorman wrote: > > > +#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT > > > +#define __defermem_init __meminit > > > +#define __defer_init __meminit > > > +#else > > > +#define __defermem_init > > > +#define __defer_init __init > > > +#endif > > > > Could we get some comments describing these? What they do, when and > > where they should be used. I have a suspicion that the naming isn't > > good, but I didn't spend a lot of time reverse-engineering the > > intent... > > > > Of course. The next version will have > > +/* > + * Deferred struct page initialisation requires some early init functions that > + * are removed before kswapd is up and running. The feature depends on memory > + * hotplug so put the data and code required by deferred initialisation into > + * the __meminit section where they are preserved. > + */ I'm still not getting it even a little bit :( You say "data and code", so I'd expect to see #define __defer_meminitdata __meminitdata #define __defer_meminit __meminit But the patch doesn't mention the data segment at all. The patch uses both __defermem_init and __defer_init to tag functions (ie: text) and I can't work out why. -- 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