* [patch] GFP_ZONEMASK vs. MAX_NR_ZONES
@ 2003-03-18 1:53 Matthew Dobson
2003-03-18 2:54 ` William Lee Irwin III
0 siblings, 1 reply; 2+ messages in thread
From: Matthew Dobson @ 2003-03-18 1:53 UTC (permalink / raw)
To: Andrew Morton, Martin J. Bligh, William Lee Irwin III, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 1012 bytes --]
Ok... hot on the heels of the other GFP_ZONEMASK patch:
struct bootmem_data;
typedef struct pglist_data {
struct zone node_zones[MAX_NR_ZONES];
struct zonelist node_zonelists[GFP_ZONEMASK+1];
int nr_zones;
struct page *node_mem_map;
unsigned long *valid_addr_bitmap;
struct bootmem_data *bdata;
unsigned long node_start_pfn;
unsigned long node_size;
int node_id;
struct pglist_data *pgdat_next;
wait_queue_head_t kswapd_wait;
} pg_data_t;
node_zonelists looks like it should really be declared of size
MAX_NR_ZONES, not GFP_ZONEMASK. GFP_ZONEMASK is currently 15, making
node_zonelists an array of 16 elements. The extra zonelists are all
just duplicates of the *real* zonelists, namely the first 3 entries.
Again, if anyone can explain to me why I'm wrong in my thinking, I'd
love to know. There's certainly no way you could bitwise-and something
with any combination of the GFP_DMA and GFP_HIGHMEM flags to refer to
the 12th zonelist or some such! Or am I crazy?
Cheers!
-Matt
[-- Attachment #2: zonelist_fix-2.5.65.patch --]
[-- Type: text/plain, Size: 1105 bytes --]
diff -Nur --exclude-from=/usr/src/.dontdiff linux-2.5.64-vanilla/include/linux/mmzone.h linux-2.5.64-zonelist_fix/include/linux/mmzone.h
--- linux-2.5.64-vanilla/include/linux/mmzone.h Tue Mar 4 19:29:22 2003
+++ linux-2.5.64-zonelist_fix/include/linux/mmzone.h Mon Mar 17 14:13:02 2003
@@ -178,7 +178,7 @@
struct bootmem_data;
typedef struct pglist_data {
struct zone node_zones[MAX_NR_ZONES];
- struct zonelist node_zonelists[GFP_ZONEMASK+1];
+ struct zonelist node_zonelists[MAX_NR_ZONES];
int nr_zones;
struct page *node_mem_map;
unsigned long *valid_addr_bitmap;
diff -Nur --exclude-from=/usr/src/.dontdiff linux-2.5.64-vanilla/mm/page_alloc.c linux-2.5.64-zonelist_fix/mm/page_alloc.c
--- linux-2.5.64-vanilla/mm/page_alloc.c Tue Mar 4 19:28:58 2003
+++ linux-2.5.64-zonelist_fix/mm/page_alloc.c Mon Mar 17 14:13:02 2003
@@ -1028,7 +1028,7 @@
local_node = pgdat->node_id;
printk("Building zonelist for node : %d\n", local_node);
- for (i = 0; i <= GFP_ZONEMASK; i++) {
+ for (i = 0; i < MAX_NR_ZONES; i++) {
struct zonelist *zonelist;
zonelist = pgdat->node_zonelists + i;
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [patch] GFP_ZONEMASK vs. MAX_NR_ZONES
2003-03-18 1:53 [patch] GFP_ZONEMASK vs. MAX_NR_ZONES Matthew Dobson
@ 2003-03-18 2:54 ` William Lee Irwin III
0 siblings, 0 replies; 2+ messages in thread
From: William Lee Irwin III @ 2003-03-18 2:54 UTC (permalink / raw)
To: Matthew Dobson; +Cc: Andrew Morton, Martin J. Bligh, linux-kernel
On Mon, Mar 17, 2003 at 05:53:08PM -0800, Matthew Dobson wrote:
> node_zonelists looks like it should really be declared of size
> MAX_NR_ZONES, not GFP_ZONEMASK. GFP_ZONEMASK is currently 15, making
> node_zonelists an array of 16 elements. The extra zonelists are all
> just duplicates of the *real* zonelists, namely the first 3 entries.
> Again, if anyone can explain to me why I'm wrong in my thinking, I'd
> love to know. There's certainly no way you could bitwise-and something
> with any combination of the GFP_DMA and GFP_HIGHMEM flags to refer to
> the 12th zonelist or some such! Or am I crazy?
No, you're not crazy, you're right:
#define __GFP_DMA 0x01
#define __GFP_HIGHMEM 0x02
/* Action modifiers - doesn't change the zoning */
#define __GFP_WAIT 0x10 /* Can wait and reschedule? */
#define __GFP_HIGH 0x20 /* Should access emergency pools? */
#define __GFP_IO 0x40 /* Can start physical IO? */
#define __GFP_FS 0x80 /* Can call down to low-level FS? */
#define __GFP_COLD 0x100 /* Cache-cold page required */
#define __GFP_NOWARN 0x200 /* Suppress page allocation failure warning */
bits 3-6 of gfp masks are totally unused.
-- wli
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2003-03-18 1:53 [patch] GFP_ZONEMASK vs. MAX_NR_ZONES Matthew Dobson
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