[PATCH] zoned vm counters: conversion of nr_pagecache to per zone counter

Currently a single atomic variable is used to establish the size of the page
cache in the whole machine.  The zoned VM counters have the same method of
implementation as the nr_pagecache code but also allow the determination of
the pagecache size per zone.

Remove the special implementation for nr_pagecache and make it a zoned counter
named NR_FILE_PAGES.

Updates of the page cache counters are always performed with interrupts off.
We can therefore use the __ variant here.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 4 insertions, 3 deletions

diff --git a/arch/s390/appldata/appldata_mem.c b/arch/s390/appldata/appldata_mem.c
index 7915a197d96d..180ba79a6267 100644
--- a/arch/s390/appldata/appldata_mem.c
+++ b/arch/s390/appldata/appldata_mem.c
@@ -130,7 +130,8 @@ static void appldata_get_mem_data(void *data)
         mem_data->totalhigh = P2K(val.totalhigh);
         mem_data->freehigh  = P2K(val.freehigh);
         mem_data->bufferram = P2K(val.bufferram);
-        mem_data->cached    = P2K(atomic_read(&nr_pagecache) - val.bufferram);
+        mem_data->cached    = P2K(global_page_state(NR_FILE_PAGES)
+                                - val.bufferram);
 
         si_swapinfo(&val);
         mem_data->totalswap = P2K(val.totalswap);
diff --git a/arch/sparc/kernel/sys_sunos.c b/arch/sparc/kernel/sys_sunos.c
index 288de276d9ff..aa0fb2efb615 100644
--- a/arch/sparc/kernel/sys_sunos.c
+++ b/arch/sparc/kernel/sys_sunos.c
@@ -196,7 +196,7 @@ asmlinkage int sunos_brk(unsigned long brk)
          * simple, it hopefully works in most obvious cases.. Easy to
          * fool it, but this should catch most mistakes.
          */
-        freepages = get_page_cache_size();
+        freepages = global_page_state(NR_FILE_PAGES);
         freepages >>= 1;
         freepages += nr_free_pages();
         freepages += nr_swap_pages;
diff --git a/arch/sparc64/kernel/sys_sunos32.c b/arch/sparc64/kernel/sys_sunos32.c
index ae5b32f817f0..87ebdf858a3a 100644
--- a/arch/sparc64/kernel/sys_sunos32.c
+++ b/arch/sparc64/kernel/sys_sunos32.c
@@ -155,7 +155,7 @@ asmlinkage int sunos_brk(u32 baddr)
          * simple, it hopefully works in most obvious cases.. Easy to
          * fool it, but this should catch most mistakes.
          */
-        freepages = get_page_cache_size();
+        freepages = global_page_state(NR_FILE_PAGES);
         freepages >>= 1;
         freepages += nr_free_pages();
         freepages += nr_swap_pages;