Re: [PATCH] for_each_pgdat

Martin J. Bligh
2002-07-20T20:41:14Z

> This patch implements for_each_pgdat(pg_data_t *) which is a helper
> macro to cleanup code that does a loop of the form:
>
> pgdat = pgdat_list;
> while(pgdat) {
> /* ... */
> pgdat = pgdat->node_next;
> }
>
> and replace it with:
>
> for_each_pgdat(pgdat) {
> /* ... */
> }

If you're going to do that (which I think is a good idea) can you
rename node_next to pgdat_next, as it often has nothing to do with
nodes whatsoever (discontigmem on a non-NUMA machine, or even more
confusingly a NUMA machine which is discontig within a node)? I'll
attatch a patch below, but it conflicts what what you're doing
horribly, and it's even easier to do after your abtraction ...

diff -urN virgin-2.5.25/arch/ia64/mm/init.c 2.5.25-A02-pgdat_next/arch/ia64/mm/init.c
--- virgin-2.5.25/arch/ia64/mm/init.c Fri Jul 5 16:42:22 2002
+++ 2.5.25-A02-pgdat_next/arch/ia64/mm/init.c Fri Jul 19 10:33:48 2002
@@ -184,7 +184,7 @@
printk("\t%d reserved pages\n", reserved);
printk("\t%d pages shared\n", shared);
printk("\t%d pages swap cached\n", cached);
- pgdat = pgdat->node_next;
+ pgdat = pgdat->pgdat_next;
} while (pgdat);
printk("Total of %ld pages in page table cache\n", pgtable_cache_size);
printk("%d free buffer pages\n", nr_free_buffer_pages());
diff -urN virgin-2.5.25/include/linux/mmzone.h 2.5.25-A02-pgdat_next/include/linux/mmzone.h
--- virgin-2.5.25/include/linux/mmzone.h Fri Jul 5 16:42:02 2002
+++ 2.5.25-A02-pgdat_next/include/linux/mmzone.h Fri Jul 19 10:34:12 2002
@@ -136,11 +136,11 @@
unsigned long node_start_mapnr;
unsigned long node_size;
int node_id;
- struct pglist_data *node_next;
+ struct pglist_data *pgdat_next; /* global chain of pg_data_t's */
} pg_data_t;

extern int numnodes;
-extern pg_data_t *pgdat_list;
+extern pg_data_t *pgdat_list; /* head of global chain of pg_data_t's */

static inline int memclass(zone_t *pgzone, zone_t *classzone)
{
diff -urN virgin-2.5.25/mm/bootmem.c 2.5.25-A02-pgdat_next/mm/bootmem.c
--- virgin-2.5.25/mm/bootmem.c Fri Jul 5 16:42:20 2002
+++ 2.5.25-A02-pgdat_next/mm/bootmem.c Thu Jul 18 16:04:54 2002
@@ -49,7 +49,7 @@
bootmem_data_t *bdata = pgdat->bdata;
unsigned long mapsize = ((end - start)+7)/8;

- pgdat->node_next = pgdat_list;
+ pgdat->pgdat_next = pgdat_list;
pgdat_list = pgdat;

mapsize = (mapsize + (sizeof(long) - 1UL)) & ~(sizeof(long) - 1UL);
@@ -343,7 +343,7 @@
if ((ptr = __alloc_bootmem_core(pgdat->bdata, size,
align, goal)))
return(ptr);
- pgdat = pgdat->node_next;
+ pgdat = pgdat->pgdat_next;
}
/*
* Whoops, we cannot satisfy the allocation request.
diff -urN virgin-2.5.25/mm/numa.c 2.5.25-A02-pgdat_next/mm/numa.c
--- virgin-2.5.25/mm/numa.c Fri Jul 5 16:42:20 2002
+++ 2.5.25-A02-pgdat_next/mm/numa.c Thu Jul 18 15:21:16 2002
@@ -109,20 +109,20 @@
spin_lock_irqsave(&node_lock, flags);
if (!next) next = pgdat_list;
temp = next;
- next = next->node_next;
+ next = next->pgdat_next;
spin_unlock_irqrestore(&node_lock, flags);
#endif
start = temp;
while (temp) {
if ((ret = alloc_pages_pgdat(temp, gfp_mask, order)))
return(ret);
- temp = temp->node_next;
+ temp = temp->pgdat_next;
}
temp = pgdat_list;
while (temp != start) {
if ((ret = alloc_pages_pgdat(temp, gfp_mask, order)))
return(ret);
- temp = temp->node_next;
+ temp = temp->pgdat_next;
}
return(0);
}
diff -urN virgin-2.5.25/mm/page_alloc.c 2.5.25-A02-pgdat_next/mm/page_alloc.c
--- virgin-2.5.25/mm/page_alloc.c Fri Jul 5 16:42:03 2002
+++ 2.5.25-A02-pgdat_next/mm/page_alloc.c Thu Jul 18 15:25:35 2002
@@ -477,7 +477,7 @@
unsigned int i, sum = 0;
pg_data_t *pgdat;

- for (pgdat = pgdat_list; pgdat; pgdat = pgdat->node_next)
+ for (pgdat = pgdat_list; pgdat; pgdat = pgdat->pgdat_next)
for (i = 0; i < MAX_NR_ZONES; ++i)
sum += pgdat->node_zones[i].free_pages;

@@ -501,7 +501,7 @@
sum += size - high;
}

- pgdat = pgdat->node_next;
+ pgdat = pgdat->pgdat_next;
} while (pgdat);

return sum;
@@ -531,7 +531,7 @@

while (pgdat) {
pages += pgdat->node_zones[ZONE_HIGHMEM].free_pages;
- pgdat = pgdat->node_next;
+ pgdat = pgdat->pgdat_next;
}
return pages;
}
@@ -621,7 +621,7 @@
K(zone->pages_low),
K(zone->pages_high));

- tmpdat = tmpdat->node_next;
+ tmpdat = tmpdat->pgdat_next;
}

printk("( Active:%lu inactive:%lu dirty:%lu writeback:%lu free:%u )\n",
diff -urN virgin-2.5.25/mm/vmscan.c 2.5.25-A02-pgdat_next/mm/vmscan.c
--- virgin-2.5.25/mm/vmscan.c Fri Jul 5 16:42:05 2002
+++ 2.5.25-A02-pgdat_next/mm/vmscan.c Thu Jul 18 15:28:03 2002
@@ -747,7 +747,7 @@
pgdat = pgdat_list;
do
need_more_balance |= kswapd_balance_pgdat(pgdat);
- while ((pgdat = pgdat->node_next));
+ while ((pgdat = pgdat->pgdat_next));
} while (need_more_balance);
}

@@ -775,7 +775,7 @@
if (kswapd_can_sleep_pgdat(pgdat))
continue;
return 0;
- } while ((pgdat = pgdat->node_next));
+ } while ((pgdat = pgdat->pgdat_next));

return 1;
}