From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx124.postini.com [74.125.245.124]) by kanga.kvack.org (Postfix) with SMTP id D22586B0002 for ; Tue, 5 Mar 2013 14:47:25 -0500 (EST) Date: Tue, 5 Mar 2013 20:47:22 +0100 From: Sam Ravnborg Subject: Re: [RFC PATCH v1 01/33] mm: introduce common help functions to deal with reserved/managed pages Message-ID: <20130305194722.GA12225@merkur.ravnborg.org> References: <1362495317-32682-1-git-send-email-jiang.liu@huawei.com> <1362495317-32682-2-git-send-email-jiang.liu@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1362495317-32682-2-git-send-email-jiang.liu@huawei.com> Sender: owner-linux-mm@kvack.org List-ID: To: Jiang Liu Cc: Andrew Morton , David Rientjes , Jiang Liu , Wen Congyang , Maciej Rutecki , Chris Clayton , "Rafael J . Wysocki" , Mel Gorman , Minchan Kim , KAMEZAWA Hiroyuki , Michal Hocko , Jianguo Wu , Anatolij Gustschin , Aurelien Jacquiot , Benjamin Herrenschmidt , Catalin Marinas , Chen Liqin , Chris Metcalf , Chris Zankel , David Howells , "David S. Miller" , Eric Biederman , Fenghua Yu , Geert Uytterhoeven , Guan Xuetao , Haavard Skinnemoen , Hans-Christian Egtvedt , Heiko Carstens , Helge Deller , Hirokazu Takata , "H. Peter Anvin" , Ingo Molnar , Ivan Kokshaysky , "James E.J. Bottomley" , Jeff Dike , Jeremy Fitzhardinge , Jonas Bonn , Koichi Yasutake , Konrad Rzeszutek Wilk , Lennox Wu , Mark Salter , Martin Schwidefsky , Matt Turner , Max Filippov , "Michael S. Tsirkin" , Michal Simek , Michel Lespinasse , Mikael Starvik , Mike Frysinger , Paul Mackerras , Paul Mundt , Ralf Baechle , Richard Henderson , Rik van Riel , Russell King , Rusty Russell , Tang Chen , Thomas Gleixner , Tony Luck , Will Deacon , Yasuaki Ishimatsu , Yinghai Lu , Yoshinori Sato , x86@kernel.org, xen-devel@lists.xensource.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, virtualization@lists.linux-foundation.org On Tue, Mar 05, 2013 at 10:54:44PM +0800, Jiang Liu wrote: > Code to deal with reserved/managed pages are duplicated by many > architectures, so introduce common help functions to reduce duplicated > code. These common help functions will also be used to concentrate code > to modify totalram_pages and zone->managed_pages, which makes the code > much more clear. > > Signed-off-by: Jiang Liu > --- > include/linux/mm.h | 37 +++++++++++++++++++++++++++++++++++++ > mm/page_alloc.c | 20 ++++++++++++++++++++ > 2 files changed, 57 insertions(+) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 7acc9dc..881461c 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1295,6 +1295,43 @@ extern void free_area_init_node(int nid, unsigned long * zones_size, > unsigned long zone_start_pfn, unsigned long *zholes_size); > extern void free_initmem(void); > > +/* Help functions to deal with reserved/managed pages. */ > +extern unsigned long free_reserved_area(unsigned long start, unsigned long end, > + int poison, char *s); > + > +static inline void adjust_managed_page_count(struct page *page, long count) > +{ > + totalram_pages += count; > +} What is the purpose of the unused page argument? > + > +static inline void __free_reserved_page(struct page *page) > +{ > + ClearPageReserved(page); > + init_page_count(page); > + __free_page(page); > +} This method is useful for architectures which implment HIGHMEM, like 32 bit x86 and 32 bit sparc. This calls for a name without underscores. > + > +static inline void free_reserved_page(struct page *page) > +{ > + __free_reserved_page(page); > + adjust_managed_page_count(page, 1); > +} > + > +static inline void mark_page_reserved(struct page *page) > +{ > + SetPageReserved(page); > + adjust_managed_page_count(page, -1); > +} > + > +static inline void free_initmem_default(int poison) > +{ Why request user to supply the poison argumet. If this is the default implmentation then use the default poison value too (POISON_FREE_INITMEM) > + extern char __init_begin[], __init_end[]; > + > + free_reserved_area(PAGE_ALIGN((unsigned long)&__init_begin) , > + ((unsigned long)&__init_end) & PAGE_MASK, > + poison, "unused kernel"); > +} Maybe it is just me how is not used to this area of the kernel. But a few comments that describe what the purpose is of each function would have helped me. Sam -- 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