lkml.org 
[lkml]   [2009]   [Jul]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Subject[PATCH] hibernate / memory hotplug: always use for_each_populated_zone()
From
Date
From: Gerald Schaefer <gerald.schaefer@de.ibm.com>

Use for_each_populated_zone() instead of for_each_zone() in hibernation
code. This fixes a bug on s390, where we allow both config options
HIBERNATION and MEMORY_HOTPLUG, so that we also have a ZONE_MOVABLE
here. We only allow hibernation if no memory hotplug operation was
performed, so in fact both features can only be used exclusively, but
this way we don't need 2 differently configured (distribution) kernels.

If we have an unpopulated ZONE_MOVABLE, we allow hibernation but run
into a BUG_ON() in memory_bm_test/set/clear_bit() because hibernation
code iterates through all zones, not only the populated zones, in
several places. For example, swsusp_free() does for_each_zone() and
then checks for pfn_valid(), which is true even if the zone is not
populated, resulting in a BUG_ON() later because the pfn cannot be
found in the memory bitmap.

Replacing all occurences of for_each_zone() in hibernation code with
for_each_populated_zone() would fix this issue.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
---
kernel/power/snapshot.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

Index: linux-2.6-work/kernel/power/snapshot.c
===================================================================
--- linux-2.6-work.orig/kernel/power/snapshot.c
+++ linux-2.6-work/kernel/power/snapshot.c
@@ -853,7 +853,7 @@ static unsigned int count_highmem_pages(
struct zone *zone;
unsigned int n = 0;

- for_each_zone(zone) {
+ for_each_populated_zone(zone) {
unsigned long pfn, max_zone_pfn;

if (!is_highmem(zone))
@@ -916,7 +916,7 @@ static unsigned int count_data_pages(voi
unsigned long pfn, max_zone_pfn;
unsigned int n = 0;

- for_each_zone(zone) {
+ for_each_populated_zone(zone) {
if (is_highmem(zone))
continue;

@@ -1010,7 +1010,7 @@ copy_data_pages(struct memory_bitmap *co
struct zone *zone;
unsigned long pfn;

- for_each_zone(zone) {
+ for_each_populated_zone(zone) {
unsigned long max_zone_pfn;

mark_free_pages(zone);
@@ -1046,7 +1046,7 @@ void swsusp_free(void)
struct zone *zone;
unsigned long pfn, max_zone_pfn;

- for_each_zone(zone) {
+ for_each_populated_zone(zone) {
max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
if (pfn_valid(pfn)) {
@@ -1166,7 +1166,7 @@ static int enough_free_mem(unsigned int
struct zone *zone;
unsigned int free = 0, meta = 0;

- for_each_zone(zone) {
+ for_each_populated_zone(zone) {
meta += snapshot_additional_pages(zone);
if (!is_highmem(zone))
free += zone_page_state(zone, NR_FREE_PAGES);
@@ -1474,7 +1474,7 @@ static int mark_unsafe_pages(struct memo
unsigned long pfn, max_zone_pfn;

/* Clear page flags */
- for_each_zone(zone) {
+ for_each_populated_zone(zone) {
max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
if (pfn_valid(pfn))


\
 
 \ /
  Last update: 2009-07-20 17:29    [W:0.076 / U:5.744 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site