[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>

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 8cba76c..0d1a598 100644 (file)
--- 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 088712f..7cff958 100644 (file)
--- 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);
                        }