From 066fed59d8a1bab4f3213e8fe413c54e4a76b77a Mon Sep 17 00:00:00 2001 From: "Uladzislau Rezki (Sony)" Date: Fri, 5 Nov 2021 13:39:34 -0700 Subject: mm/vmalloc: check various alignments when debugging Before we did not guarantee a free block with lowest start address for allocations with alignment >= PAGE_SIZE. Because an alignment overhead was included into a search length like below: length = size + align - 1; doing so we make sure that a bigger block would fit after applying an alignment adjustment. Now there is no such limitation, i.e. any alignment that user wants to apply will result to a lowest address of returned free area. Link: https://lkml.kernel.org/r/20211004142829.22222-2-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) Cc: Christoph Hellwig Cc: David Hildenbrand Cc: Hillf Danton Cc: Matthew Wilcox Cc: Mel Gorman Cc: Michal Hocko Cc: Nicholas Piggin Cc: Oleksiy Avramchenko Cc: Ping Fang Cc: Steven Rostedt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmalloc.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 0d835bd7fb5f..d4770396799a 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1269,7 +1269,7 @@ find_vmap_lowest_linear_match(unsigned long size, } static void -find_vmap_lowest_match_check(unsigned long size) +find_vmap_lowest_match_check(unsigned long size, unsigned long align) { struct vmap_area *va_1, *va_2; unsigned long vstart; @@ -1278,8 +1278,8 @@ find_vmap_lowest_match_check(unsigned long size) get_random_bytes(&rnd, sizeof(rnd)); vstart = VMALLOC_START + rnd; - va_1 = find_vmap_lowest_match(size, 1, vstart); - va_2 = find_vmap_lowest_linear_match(size, 1, vstart); + va_1 = find_vmap_lowest_match(size, align, vstart); + va_2 = find_vmap_lowest_linear_match(size, align, vstart); if (va_1 != va_2) pr_emerg("not lowest: t: 0x%p, l: 0x%p, v: 0x%lx\n", @@ -1458,7 +1458,7 @@ __alloc_vmap_area(unsigned long size, unsigned long align, return vend; #if DEBUG_AUGMENT_LOWEST_MATCH_CHECK - find_vmap_lowest_match_check(size); + find_vmap_lowest_match_check(size, align); #endif return nva_start_addr; -- cgit v1.2.3-58-ga151