Commit 53bddb4e authored Mar 10, 2010 by KAMEZAWA Hiroyuki Committed by Linus Torvalds Mar 12, 2010

nommu: fix build breakage



Commit 34e55232 ("mm: avoid false sharing
of mm_counter") added sync_mm_rss() for syncing loosely accounted rss
counters.  It's for CONFIG_MMU but sync_mm_rss is called even in NOMMU
enviroment (kerne/exit.c, fs/exec.c).  Above commit doesn't handle it
well.

This patch changes
  SPLIT_RSS_COUNTING depends on SPLIT_PTLOCKS && CONFIG_MMU

And for avoid unnecessary function calls, sync_mm_rss changed to be inlined
noop function in header file.

Reported-by: David Howells <dhowells@redhat.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Michal Simek <monstr@monstr.eu>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 936ed49a

include/linux/mm.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -971,7 +971,13 @@ static inline void setmax_mm_hiwater_rss(unsigned long *maxrss,
		*maxrss = hiwater_rss;
		}

		#if defined(SPLIT_RSS_COUNTING)
		void sync_mm_rss(struct task_struct task, struct mm_struct mm);
		#else
		static inline void sync_mm_rss(struct task_struct task, struct mm_struct mm)
		{
		}
		#endif

		/*
		* A callback you can register to apply pressure to ageable caches.

include/linux/mm_types.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -203,7 +203,7 @@ enum {
		NR_MM_COUNTERS
		};

		#if USE_SPLIT_PTLOCKS
		#if USE_SPLIT_PTLOCKS && defined(CONFIG_MMU)
		#define SPLIT_RSS_COUNTING
		struct mm_rss_stat {
		atomic_long_t count[NR_MM_COUNTERS];

mm/memory.c

+0 −3

Original line number	Diff line number	Diff line
		@@ -190,9 +190,6 @@ static void check_sync_rss_stat(struct task_struct *task)
		{
		}

		void sync_mm_rss(struct task_struct task, struct mm_struct mm)
		{
		}
		#endif

		/*

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