On Thu, Jun 16, 2011 at 05:28:19PM +0900, KAMEZAWA Hiroyuki wrote: > On Wed, 15 Jun 2011 21:49:17 -0700 > Randy Dunlap <randy.dunlap@xxxxxxxxxx> wrote: > > > On Wed, 15 Jun 2011 16:56:49 -0700 akpm@xxxxxxxxxxxxxxxxxxxx wrote: > > > > > The mm-of-the-moment snapshot 2011-06-15-16-56 has been uploaded to > > > > > > http://userweb.kernel.org/~akpm/mmotm/ > > > > > > and will soon be available at > > > git://zen-kernel.org/kernel/mmotm.git > > > or > > > git://git.cmpxchg.org/linux-mmotm.git > > > > > > It contains the following patches against 3.0-rc3: > > > > > > (x86_64 build:) > > > > mm/page_cgroup.c: In function 'page_cgroup_init': > > mm/page_cgroup.c:308: error: implicit declaration of function 'node_start_pfn' > > mm/page_cgroup.c:309: error: implicit declaration of function 'node_end_pfn' > > > > > > Bug fix is here. Added CC to Mel to get review. > == > From add3b670119f1c1f762194b432d3997d595bc213 Mon Sep 17 00:00:00 2001 > From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> > Date: Thu, 16 Jun 2011 17:28:07 +0900 > Subject: [PATCH] Fix node_start/end_pfn() definition for mm/page_cgroup.c > > commit 21a3c96 uses node_start/end_pfn(nid) for detection start/end > of nodes. But, it's not defined in linux/mmzone.h but defined in > /arch/???/include/mmzone.h which is included only under > CONFIG_NEED_MULTIPLE_NODES=y. > > Then, we see > mm/page_cgroup.c: In function 'page_cgroup_init': > mm/page_cgroup.c:308: error: implicit declaration of function 'node_start_pfn' > mm/page_cgroup.c:309: error: implicit declaration of function 'node_end_pfn' > > So, fixing page_cgroup.c is an idea... > > But node_start_pfn()/node_end_pfn() is a very generic macro and > should be implemented in the same manner for all archs. > (m32r has different implementation...) > I would expect node_start_pfn to always be the equivalent of NODE_DATA(nid)->node_start_pfn and that does appear to be case even though it is not universally defined; alpha/include/asm/mmzone.h:#define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn) m32r/include/asm/mmzone.h:#define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn) parisc/include/asm/mmzone.h:#define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn) powerpc/include/asm/mmzone.h:#define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn) sh/include/asm/mmzone.h:#define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn) sparc/include/asm/mmzone.h:#define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn) tile/include/asm/mmzone.h:#define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn) x86/include/asm/mmzone_32.h:#define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn) x86/include/asm/mmzone_64.h:#define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn) Similarly I would always expect node_end_pfn to be related to node_spanned_pages which is true of x86, tile, sh and parisc. sparc and powerpc uses node_end_pfn which is a good trick because that is not a member of pglist_data (suspect they do not build on !CONFIG_NEED_MULTIPLE_NODES?). m32r does differ from everyone else in that it's __pgdat->node_start_pfn + __pgdat->node_spanned_pages - 1 and this was the case when it was introduced in 2004. It's not explained why it is like this but I suspect it's a mistake and I think your cleanup is appropriate. > This patch removes definitions of node_start/end_pfn() in each archs > and defines a unified one in linux/mmzone.h. It's not under > CONFIG_NEED_MULTIPLE_NODES, now. > Does anyone remember *why* this did not happen in the first place? I can't think of a good reason so I've cc'd Dave Hansen as he might remember. Would it also be worth cleaning up users of node_spanned_pages to use node_end_pfn in mm/ where appropriate rather than having a mix of spanned_pages and node_end_pfn? > Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> For the most part, it looks good! I haven't compile-tested this but I did spot one one problem unfortunately; > <SNIP> > diff --git a/arch/x86/include/asm/mmzone_32.h b/arch/x86/include/asm/mmzone_32.h > index 5e83a41..224e8c5 100644 > --- a/arch/x86/include/asm/mmzone_32.h > +++ b/arch/x86/include/asm/mmzone_32.h > @@ -48,17 +48,6 @@ static inline int pfn_to_nid(unsigned long pfn) > #endif > } > > -/* > - * Following are macros that each numa implmentation must define. > - */ > - > -#define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn) > -#define node_end_pfn(nid) \ > -({ \ > - pg_data_t *__pgdat = NODE_DATA(nid); \ > - __pgdat->node_start_pfn + __pgdat->node_spanned_pages; \ > -}) > - > static inline int pfn_valid(int pfn) > { > int nid = pfn_to_nid(pfn); > diff --git a/arch/x86/include/asm/mmzone_64.h b/arch/x86/include/asm/mmzone_64.h > index b3f88d7..129d9aa 100644 > --- a/arch/x86/include/asm/mmzone_64.h > +++ b/arch/x86/include/asm/mmzone_64.h > @@ -13,8 +13,5 @@ extern struct pglist_data *node_data[]; > > #define NODE_DATA(nid) (node_data[nid]) > > -#define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn) > -#define node_end_pfn(nid) (NODE_DATA(nid)->node_start_pfn + \ > - NODE_DATA(nid)->node_spanned_pages) > #endif > #endif /* _ASM_X86_MMZONE_64_H */ > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > index c928dac..892862e 100644 > --- a/include/linux/mmzone.h > +++ b/include/linux/mmzone.h > @@ -647,6 +647,9 @@ typedef struct pglist_data { > #endif > #define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr)) > > +#define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn) > +#define node_end_pfn(nid) (node_start_pfn(nid) + node_spanned_pages(nid)) > + A caller that does node_end_pfn(nid++) will get a nasty surprise due to side-effects. I know architectures currently get this wrong including x86_64 but we might as well fix it up now. The definition in arch/x86/include/asm/mmzone_32.h is immune to side-effects and might be a better choice despite the use of a temporary variable. > #include <linux/memory_hotplug.h> > > extern struct mutex zonelists_mutex; > -- > 1.7.4.1 > > -- Mel Gorman SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>