Commit a4b065fa authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds

[PATCH] for_each_zone macro

Patch from Robert Love.

Attached patch implements for_each_zone(zont_t *) which is a helper
macro to cleanup code of the form:

        for (pgdat = pgdat_list; pgdat; pgdat = pgdat->node_next) {
                for (i = 0; i < MAX_NR_ZONES; ++i) {
                        zone_t * z = pgdat->node_zones + i;
                        /* ... */
                }
        }

and replace it with:

        for_each_zone(zone) {
                /* ... */
        }

This patch only replaces one use of the above loop with the new macro.
Pending code, however, currently in the full rmap patch uses
for_each_zone more extensively.
parent f183c478
...@@ -177,6 +177,43 @@ extern pg_data_t contig_page_data; ...@@ -177,6 +177,43 @@ extern pg_data_t contig_page_data;
#define for_each_pgdat(pgdat) \ #define for_each_pgdat(pgdat) \
for (pgdat = pgdat_list; pgdat; pgdat = pgdat->pgdat_next) for (pgdat = pgdat_list; pgdat; pgdat = pgdat->pgdat_next)
/*
* next_zone - helper magic for for_each_zone()
* Thanks to William Lee Irwin III for this piece of ingenuity.
*/
static inline zone_t * next_zone(zone_t * zone)
{
pg_data_t *pgdat = zone->zone_pgdat;
if (zone - pgdat->node_zones < MAX_NR_ZONES - 1)
zone++;
else if (pgdat->pgdat_next) {
pgdat = pgdat->pgdat_next;
zone = pgdat->node_zones;
} else
zone = NULL;
return zone;
}
/**
* for_each_zone - helper macro to iterate over all memory zones
* @zone - pointer to zone_t variable
*
* The user only needs to declare the zone variable, for_each_zone
* fills it in. This basically means for_each_zone() is an
* easier to read version of this piece of code:
*
* for (pgdat = pgdat_list; pgdat; pgdat = pgdat->node_next)
* for (i = 0; i < MAX_NR_ZONES; ++i) {
* zone_t * z = pgdat->node_zones + i;
* ...
* }
* }
*/
#define for_each_zone(zone) \
for (zone = pgdat_list->node_zones; zone; zone = next_zone(zone))
#ifndef CONFIG_DISCONTIGMEM #ifndef CONFIG_DISCONTIGMEM
#define NODE_DATA(nid) (&contig_page_data) #define NODE_DATA(nid) (&contig_page_data)
......
...@@ -477,12 +477,11 @@ void free_pages(unsigned long addr, unsigned int order) ...@@ -477,12 +477,11 @@ void free_pages(unsigned long addr, unsigned int order)
*/ */
unsigned int nr_free_pages(void) unsigned int nr_free_pages(void)
{ {
unsigned int i, sum = 0; unsigned int sum = 0;
pg_data_t *pgdat; zone_t *zone;
for (pgdat = pgdat_list; pgdat; pgdat = pgdat->pgdat_next) for_each_zone(zone)
for (i = 0; i < MAX_NR_ZONES; ++i) sum += zone->free_pages;
sum += pgdat->node_zones[i].free_pages;
return sum; return sum;
} }
......
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