From e6e07b696da529e85d1ba880555b5df5c80a46bd Mon Sep 17 00:00:00 2001 From: "T.J. Mercier" Date: Wed, 9 Apr 2025 22:51:11 +0000 Subject: [PATCH] alloc_tag: handle incomplete bulk allocations in vm_module_tags_populate alloc_pages_bulk_node() may partially succeed and allocate fewer than the requested nr_pages. There are several conditions under which this can occur, but we have encountered the case where CONFIG_PAGE_OWNER is enabled causing all bulk allocations to always fallback to single page allocations due to commit 187ad460b841 ("mm/page_alloc: avoid page allocator recursion with pagesets.lock held"). Currently vm_module_tags_populate() immediately fails when alloc_pages_bulk_node() returns fewer than the requested number of pages. When this happens memory allocation profiling gets disabled, for example [ 14.297583] [9: modprobe: 465] Failed to allocate memory for allocation tags in the module scsc_wlan. Memory allocation profiling is disabled! [ 14.299339] [9: modprobe: 465] modprobe: Failed to insmod '/vendor/lib/modules/scsc_wlan.ko' with args '': Out of memory This patch causes vm_module_tags_populate() to retry bulk allocations for the remaining memory instead of failing immediately which will avoid the disablement of memory allocation profiling. Link: https://lkml.kernel.org/r/20250409225111.3770347-1-tjmercier@google.com Fixes: 0f9b685626da ("alloc_tag: populate memory for module tags as needed") Signed-off-by: T.J. Mercier Reported-by: Janghyuck Kim Acked-by: Suren Baghdasaryan Cc: Kent Overstreet Cc: Signed-off-by: Andrew Morton --- lib/alloc_tag.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c index 1d893e313614..25ecc1334b67 100644 --- a/lib/alloc_tag.c +++ b/lib/alloc_tag.c @@ -422,11 +422,20 @@ static int vm_module_tags_populate(void) unsigned long old_shadow_end = ALIGN(phys_end, MODULE_ALIGN); unsigned long new_shadow_end = ALIGN(new_end, MODULE_ALIGN); unsigned long more_pages; - unsigned long nr; + unsigned long nr = 0; more_pages = ALIGN(new_end - phys_end, PAGE_SIZE) >> PAGE_SHIFT; - nr = alloc_pages_bulk_node(GFP_KERNEL | __GFP_NOWARN, - NUMA_NO_NODE, more_pages, next_page); + while (nr < more_pages) { + unsigned long allocated; + + allocated = alloc_pages_bulk_node(GFP_KERNEL | __GFP_NOWARN, + NUMA_NO_NODE, more_pages - nr, next_page + nr); + + if (!allocated) + break; + nr += allocated; + } + if (nr < more_pages || vmap_pages_range(phys_end, phys_end + (nr << PAGE_SHIFT), PAGE_KERNEL, next_page, PAGE_SHIFT) < 0) {