diff options
| author |   Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2023-03-15 14:31:33 +0300 |
|---|---|---|
| committer |   Andrew Morton <akpm@linux-foundation.org> | 2023-04-05 19:42:46 -0700 |
| commit | 23baf831a32c04f9a968812511540b1b3e648bf5 (patch) | |
| tree | fcaca52cefbef2707710ce057f58fb1c955a0559 /kernel | |
| parent | iommu: fix MAX_ORDER usage in __iommu_dma_alloc_pages() (diff) | |
| download | wireguard-linux-23baf831a32c04f9a968812511540b1b3e648bf5.tar.xz wireguard-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 'kernel')
| -rw-r--r-- | kernel/crash_core.c | 2 | ||||
| -rw-r--r-- | kernel/dma/pool.c | 6 | ||||
| -rw-r--r-- | kernel/events/ring_buffer.c | 6 |
3 files changed, 7 insertions, 7 deletions
diff --git a/kernel/crash_core.c b/kernel/crash_core.c index 755f5f08ab38..90ce1dfd591c 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -474,7 +474,7 @@ static int __init crash_save_vmcoreinfo_init(void) VMCOREINFO_OFFSET(list_head, prev); VMCOREINFO_OFFSET(vmap_area, va_start); VMCOREINFO_OFFSET(vmap_area, list); - VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER); + VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER + 1); log_buf_vmcoreinfo_setup(); VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES); VMCOREINFO_NUMBER(NR_FREE_PAGES); diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c index 4d40dcce7604..1acec2e22827 100644 --- a/kernel/dma/pool.c +++ b/kernel/dma/pool.c @@ -84,8 +84,8 @@ static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size, void *addr; int ret = -ENOMEM; - /* Cannot allocate larger than MAX_ORDER-1 */ - order = min(get_order(pool_size), MAX_ORDER-1); + /* Cannot allocate larger than MAX_ORDER */ + order = min(get_order(pool_size), MAX_ORDER); do { pool_size = 1 << (PAGE_SHIFT + order); @@ -190,7 +190,7 @@ static int __init dma_atomic_pool_init(void) /* * If coherent_pool was not used on the command line, default the pool - * sizes to 128KB per 1GB of memory, min 128KB, max MAX_ORDER-1. + * sizes to 128KB per 1GB of memory, min 128KB, max MAX_ORDER. */ if (!atomic_pool_size) { unsigned long pages = totalram_pages() / (SZ_1G / SZ_128K); diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c index d6bbdb7830b2..a0433f37b024 100644 --- a/kernel/events/ring_buffer.c +++ b/kernel/events/ring_buffer.c @@ -609,8 +609,8 @@ static struct page *rb_alloc_aux_page(int node, int order) { struct page *page; - if (order >= MAX_ORDER) - order = MAX_ORDER - 1; + if (order > MAX_ORDER) + order = MAX_ORDER; do { page = alloc_pages_node(node, PERF_AUX_GFP, order); @@ -814,7 +814,7 @@ struct perf_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags) size = sizeof(struct perf_buffer); size += nr_pages * sizeof(void *); - if (order_base_2(size) >= PAGE_SHIFT+MAX_ORDER) + if (order_base_2(size) > PAGE_SHIFT+MAX_ORDER) goto fail; node = (cpu == -1) ? cpu : cpu_to_node(cpu); |