[patch 8/14] mm: remove pcp_low

Nick Piggin
2005-11-06T08:23:03Z

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8/14

--
SUSE Labs, Novell Inc.

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pcp->low is useless.

Index: linux-2.6/include/linux/mmzone.h
===================================================================
--- linux-2.6.orig/include/linux/mmzone.h
+++ linux-2.6/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 */
Index: linux-2.6/mm/page_alloc.c
===================================================================
--- linux-2.6.orig/mm/page_alloc.c
+++ linux-2.6/mm/page_alloc.c
@@ -712,7 +712,7 @@ buffered_rmqueue(struct zone *zone, int

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)) {
@@ -1324,10 +1324,9 @@ 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);
@@ -1765,14 +1764,12 @@ inline void setup_pageset(struct per_cpu

pcp = &p->pcp[0]; /* hot */
pcp->count = 0;
- pcp->low = 0;
- pcp->high = 6 * batch;
+ pcp->high = 4 * 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);
@@ -2169,12 +2166,10 @@ static int zoneinfo_show(struct seq_file
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);
}