Memory return to free_contig_range() must have no other references. Let kernel to complain loudly if page reference count is not equal to 1.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Reviewed-by: Kyungmin Park kyungmin.park@samsung.com CC: Michal Nazarewicz mina86@mina86.com --- mm/page_alloc.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 022e4ed..290c2eb 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5888,8 +5888,13 @@ done:
void free_contig_range(unsigned long pfn, unsigned nr_pages) { - for (; nr_pages--; ++pfn) - __free_page(pfn_to_page(pfn)); + struct page *page = pfn_to_page(pfn); + int refcount = nr_pages; + for (; nr_pages--; page++) { + refcount -= page_count(page) == 1; + __free_page(page); + } + WARN(refcount != 0, "some pages are still in use!\n"); } #endif
On Mon, Nov 12 2012, Marek Szyprowski wrote:
Memory return to free_contig_range() must have no other references. Let kernel to complain loudly if page reference count is not equal to 1.
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 022e4ed..290c2eb 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5888,8 +5888,13 @@ done: void free_contig_range(unsigned long pfn, unsigned nr_pages) {
- for (; nr_pages--; ++pfn)
__free_page(pfn_to_page(pfn));
- struct page *page = pfn_to_page(pfn);
- int refcount = nr_pages;
- for (; nr_pages--; page++) {
refcount -= page_count(page) == 1;__free_page(page);- }
- WARN(refcount != 0, "some pages are still in use!\n");
This decrementing logic seem backward to me. Why not:
struct page *page = pfn_to_page(pfn); unsigned int refcount = 0; for (; nr_pages--; page++) { refcount += page_count(page) != 1; __free_page(page); } WARN(refcount != 0, "some pages are still in use!\n");
} #endif
Memory returned to free_contig_range() must have no other references. Let kernel to complain loudly if page reference count is not equal to 1.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Reviewed-by: Kyungmin Park kyungmin.park@samsung.com CC: Michal Nazarewicz mina86@mina86.com --- mm/page_alloc.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 022e4ed..290c2eb 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5888,8 +5888,13 @@ done:
void free_contig_range(unsigned long pfn, unsigned nr_pages) { - for (; nr_pages--; ++pfn) - __free_page(pfn_to_page(pfn)); + struct page *page = pfn_to_page(pfn); + int count = 0; + for (; nr_pages--; page++) { + count += page_count(page) != 1; + __free_page(page); + } + WARN(count != 0, "%d pages are still in use!\n", count); } #endif
On Tue, Nov 13 2012, Marek Szyprowski m.szyprowski@samsung.com wrote:
Memory returned to free_contig_range() must have no other references. Let kernel to complain loudly if page reference count is not equal to 1.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Reviewed-by: Kyungmin Park kyungmin.park@samsung.com CC: Michal Nazarewicz mina86@mina86.com
Acked-by: Michal Nazarewicz mina86@mina86.com
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 022e4ed..290c2eb 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5888,8 +5888,13 @@ done: void free_contig_range(unsigned long pfn, unsigned nr_pages) {
- for (; nr_pages--; ++pfn)
__free_page(pfn_to_page(pfn));
- struct page *page = pfn_to_page(pfn);
- int count = 0;
- for (; nr_pages--; page++) {
count += page_count(page) != 1;__free_page(page);- }
- WARN(count != 0, "%d pages are still in use!\n", count);
} #endif
linaro-mm-sig@lists.linaro.org
-
Marek Szyprowski -
Michal Nazarewicz