[PATCH] mm: remove pcp low

struct per_cpu_pages.low is useless.  Remove it.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 2 insertions, 8 deletions

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 8cba76c6a28c..0d1a5981bb94 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -46,7 +46,6 @@ struct zone_padding {
 
 struct per_cpu_pages {
         int count;              /* number of pages in the list */
-        int low;                /* low watermark, refill needed */
         int high;               /* high watermark, emptying needed */
         int batch;              /* chunk size for buddy add/remove */
         struct list_head list;  /* the list of pages */
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 088712f2ac02..7cff958e7813 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -740,7 +740,7 @@ again:
                 page = NULL;
                 pcp = &zone_pcp(zone, get_cpu())->pcp[cold];
                 local_irq_save(flags);
-                if (pcp->count <= pcp->low)
+                if (!pcp->count)
                         pcp->count += rmqueue_bulk(zone, 0,
                                                 pcp->batch, &pcp->list);
                 if (likely(pcp->count)) {
@@ -1345,10 +1345,9 @@ void show_free_areas(void)
                         pageset = zone_pcp(zone, cpu);
 
                         for (temperature = 0; temperature < 2; temperature++)
-                                printk("cpu %d %s: low %d, high %d, batch %d used:%d\n",
+                                printk("cpu %d %s: high %d, batch %d used:%d\n",
                                         cpu,
                                         temperature ? "cold" : "hot",
-                                        pageset->pcp[temperature].low,
                                         pageset->pcp[temperature].high,
                                         pageset->pcp[temperature].batch,
                                         pageset->pcp[temperature].count);
@@ -1790,14 +1789,12 @@ inline void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
 
         pcp = &p->pcp[0];               /* hot */
         pcp->count = 0;
-        pcp->low = 0;
         pcp->high = 6 * batch;
         pcp->batch = max(1UL, 1 * batch);
         INIT_LIST_HEAD(&pcp->list);
 
         pcp = &p->pcp[1];               /* cold*/
         pcp->count = 0;
-        pcp->low = 0;
         pcp->high = 2 * batch;
         pcp->batch = max(1UL, batch/2);
         INIT_LIST_HEAD(&pcp->list);
@@ -2193,12 +2190,10 @@ static int zoneinfo_show(struct seq_file *m, void *arg)
                                 seq_printf(m,
                                            "\n    cpu: %i pcp: %i"
                                            "\n              count: %i"
-                                           "\n              low:   %i"
                                            "\n              high:  %i"
                                            "\n              batch: %i",
                                            i, j,
                                            pageset->pcp[j].count,
-                                           pageset->pcp[j].low,
                                            pageset->pcp[j].high,
                                            pageset->pcp[j].batch);
                         }