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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2023-03-15 12:31:33 +0100
committerAndrew Morton <akpm@linux-foundation.org>2023-04-06 04:42:46 +0200
commit23baf831a32c04f9a968812511540b1b3e648bf5 (patch)
treefcaca52cefbef2707710ce057f58fb1c955a0559 /drivers/virtio
parentiommu: fix MAX_ORDER usage in __iommu_dma_alloc_pages() (diff)
downloadlinux-23baf831a32c04f9a968812511540b1b3e648bf5.tar.xz
linux-23baf831a32c04f9a968812511540b1b3e648bf5.zip
mm, treewide: redefine MAX_ORDER sanely
MAX_ORDER currently defined as number of orders page allocator supports: user can ask buddy allocator for page order between 0 and MAX_ORDER-1. This definition is counter-intuitive and lead to number of bugs all over the kernel. Change the definition of MAX_ORDER to be inclusive: the range of orders user can ask from buddy allocator is 0..MAX_ORDER now. [kirill@shutemov.name: fix min() warning] Link: https://lkml.kernel.org/r/20230315153800.32wib3n5rickolvh@box [akpm@linux-foundation.org: fix another min_t warning] [kirill@shutemov.name: fixups per Zi Yan] Link: https://lkml.kernel.org/r/20230316232144.b7ic4cif4kjiabws@box.shutemov.name [akpm@linux-foundation.org: fix underlining in docs] Link: https://lore.kernel.org/oe-kbuild-all/202303191025.VRCTk6mP-lkp@intel.com/ Link: https://lkml.kernel.org/r/20230315113133.11326-11-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc] Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'drivers/virtio')
-rw-r--r--drivers/virtio/virtio_balloon.c2
-rw-r--r--drivers/virtio/virtio_mem.c12
2 files changed, 7 insertions, 7 deletions
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 3f78a3a1eb75..5b15936a5214 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -33,7 +33,7 @@
#define VIRTIO_BALLOON_FREE_PAGE_ALLOC_FLAG (__GFP_NORETRY | __GFP_NOWARN | \
__GFP_NOMEMALLOC)
/* The order of free page blocks to report to host */
-#define VIRTIO_BALLOON_HINT_BLOCK_ORDER (MAX_ORDER - 1)
+#define VIRTIO_BALLOON_HINT_BLOCK_ORDER MAX_ORDER
/* The size of a free page block in bytes */
#define VIRTIO_BALLOON_HINT_BLOCK_BYTES \
(1 << (VIRTIO_BALLOON_HINT_BLOCK_ORDER + PAGE_SHIFT))
diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
index 0c2892ec6817..835f6cc2fb66 100644
--- a/drivers/virtio/virtio_mem.c
+++ b/drivers/virtio/virtio_mem.c
@@ -1120,13 +1120,13 @@ static void virtio_mem_clear_fake_offline(unsigned long pfn,
*/
static void virtio_mem_fake_online(unsigned long pfn, unsigned long nr_pages)
{
- unsigned long order = MAX_ORDER - 1;
+ unsigned long order = MAX_ORDER;
unsigned long i;
/*
* We might get called for ranges that don't cover properly aligned
- * MAX_ORDER - 1 pages; however, we can only online properly aligned
- * pages with an order of MAX_ORDER - 1 at maximum.
+ * MAX_ORDER pages; however, we can only online properly aligned
+ * pages with an order of MAX_ORDER at maximum.
*/
while (!IS_ALIGNED(pfn | nr_pages, 1 << order))
order--;
@@ -1237,9 +1237,9 @@ static void virtio_mem_online_page(struct virtio_mem *vm,
bool do_online;
/*
- * We can get called with any order up to MAX_ORDER - 1. If our
- * subblock size is smaller than that and we have a mixture of plugged
- * and unplugged subblocks within such a page, we have to process in
+ * We can get called with any order up to MAX_ORDER. If our subblock
+ * size is smaller than that and we have a mixture of plugged and
+ * unplugged subblocks within such a page, we have to process in
* smaller granularity. In that case we'll adjust the order exactly once
* within the loop.
*/