Dave McCracken
2009-Dec-21 19:36 UTC
[Xen-devel] [PATCH] linux/balloon: Fix hugepage-related bugs
Fix a couple of bugs in the hugepage changes to the Xen balloon driver.
Signed-off-by: Dave McCracken <dave.mccracken@oracle.com>
--------
balloon.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
--- 2.6-xen/drivers/xen/balloon.c 2009-12-17 14:20:57.000000000 -0600
+++ 2.6-xen-balloon//drivers/xen/balloon.c 2009-12-18 15:26:12.000000000 -0600
@@ -283,7 +283,7 @@ static int increase_reservation(unsigned
/* Relinquish the page back to the allocator. */
ClearPageReserved(page);
init_page_count(page);
- __free_page(page);
+ __free_pages(page, balloon_order);
}
balloon_stats.current_pages += rc;
@@ -531,12 +531,13 @@ struct page **alloc_empty_pages_and_page
/* Round up to next number of balloon_order pages */
npages = (nr_pages + (balloon_npages-1)) >> balloon_order;
- pagevec = kmalloc(sizeof(page) * nr_pages << balloon_order, GFP_KERNEL);
+ pagevec = kmalloc(sizeof(page) * nr_pages, GFP_KERNEL);
if (pagevec == NULL)
return NULL;
- for (i = 0; i < nr_pages; i++) {
+ for (i = 0; i < npages; i++) {
void *v;
+ int limit;
page = alloc_pages(GFP_KERNEL|__GFP_COLD, balloon_order);
if (page == NULL)
@@ -555,10 +556,14 @@ struct page **alloc_empty_pages_and_page
if (ret != 0) {
mutex_unlock(&balloon_mutex);
//balloon_free_page(page); /* tries to use free_cold_page */
- __free_page(page);
+ __free_pages(page, balloon_order);
goto err;
}
- for (j = 0; j < balloon_npages; j++)
+ if (i == (npages-1))
+ limit = nr_pages - (i << balloon_order);
+ else
+ limit = balloon_npages;
+ for (j = 0; j < limit; j++)
pagevec[(i<<balloon_order)+j] = page++;
totalram_pages = balloon_stats.current_pages -= balloon_npages;
@@ -595,7 +600,7 @@ void free_empty_pages_and_pagevec(struct
npages = (nr_pages + (balloon_npages-1)) >> balloon_order;
mutex_lock(&balloon_mutex);
- for (i = 0; i < nr_pages; i++) {
+ for (i = 0; i < npages; i++) {
page = pagevec[i << balloon_order];
BUG_ON(page_count(page) != 1);
balloon_append(page);
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Dave McCracken
2009-Dec-21 19:50 UTC
[Xen-devel] [PATCH] linux/balloon: Fix hugepage-related bugs
Fix a couple of bugs in the hugepage changes to the Xen balloon driver.
Signed-off-by: Dave McCracken <dave.mccracken@oracle.com>
--------
balloon.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
--- 2.6-xen/drivers/xen/balloon.c 2009-12-17 14:20:57.000000000 -0600
+++ 2.6-xen-balloon//drivers/xen/balloon.c 2009-12-18 15:26:12.000000000 -0600
@@ -283,7 +283,7 @@ static int increase_reservation(unsigned
/* Relinquish the page back to the allocator. */
ClearPageReserved(page);
init_page_count(page);
- __free_page(page);
+ __free_pages(page, balloon_order);
}
balloon_stats.current_pages += rc;
@@ -531,12 +531,13 @@ struct page **alloc_empty_pages_and_page
/* Round up to next number of balloon_order pages */
npages = (nr_pages + (balloon_npages-1)) >> balloon_order;
- pagevec = kmalloc(sizeof(page) * nr_pages << balloon_order, GFP_KERNEL);
+ pagevec = kmalloc(sizeof(page) * nr_pages, GFP_KERNEL);
if (pagevec == NULL)
return NULL;
- for (i = 0; i < nr_pages; i++) {
+ for (i = 0; i < npages; i++) {
void *v;
+ int limit;
page = alloc_pages(GFP_KERNEL|__GFP_COLD, balloon_order);
if (page == NULL)
@@ -555,10 +556,14 @@ struct page **alloc_empty_pages_and_page
if (ret != 0) {
mutex_unlock(&balloon_mutex);
//balloon_free_page(page); /* tries to use free_cold_page */
- __free_page(page);
+ __free_pages(page, balloon_order);
goto err;
}
- for (j = 0; j < balloon_npages; j++)
+ if (i == (npages-1))
+ limit = nr_pages - (i << balloon_order);
+ else
+ limit = balloon_npages;
+ for (j = 0; j < limit; j++)
pagevec[(i<<balloon_order)+j] = page++;
totalram_pages = balloon_stats.current_pages -= balloon_npages;
@@ -595,7 +600,7 @@ void free_empty_pages_and_pagevec(struct
npages = (nr_pages + (balloon_npages-1)) >> balloon_order;
mutex_lock(&balloon_mutex);
- for (i = 0; i < nr_pages; i++) {
+ for (i = 0; i < npages; i++) {
page = pagevec[i << balloon_order];
BUG_ON(page_count(page) != 1);
balloon_append(page);
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Jan Beulich
2009-Dec-22 07:55 UTC
[Xen-devel] Re: [PATCH] linux/balloon: Fix hugepage-related bugs
Acked-by: Jan Beulich <jbeulich@novell.com>>>> Dave McCracken <dcm@mccr.org> 21.12.09 20:50 >>> >@@ -595,7 +600,7 @@ void free_empty_pages_and_pagevec(struct > npages = (nr_pages + (balloon_npages-1)) >> balloon_order; > > mutex_lock(&balloon_mutex); >- for (i = 0; i < nr_pages; i++) { >+ for (i = 0; i < npages; i++) { > page = pagevec[i << balloon_order]; > BUG_ON(page_count(page) != 1);Wouldn''t it be reasonable to also extend this check to all constituent pages?> balloon_append(page);Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel