[RFC PATCH 13/30] mm/slab: introduce SLAB_NO_OBJ_EXT to avoid obj_ext creation
From: Suren Baghdasaryan <surenb@google.com>
Date: 2022-08-30 21:51:59
Also in:
io-uring, linux-arch, linux-bcache, linux-iommu, linux-mm, lkml, xen-devel
Subsystem:
memory management, slab allocator, the rest · Maintainers:
Andrew Morton, Vlastimil Babka, Harry Yoo, Linus Torvalds
Slab extension objects can't be allocated before slab infrastructure is initialized. Some caches, like kmem_cache and kmem_cache_node, are created before slab infrastructure is initialized. Objects from these caches can't have extension objects. Introduce SLAB_NO_OBJ_EXT slab flag to mark these caches and avoid creating extensions for objects allocated from these slabs. Signed-off-by: Suren Baghdasaryan <surenb@google.com> --- include/linux/slab.h | 7 +++++++ mm/slab.c | 2 +- mm/slub.c | 5 +++-- 3 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 0fefdf528e0d..55ae3ea864a4 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h@@ -124,6 +124,13 @@ #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0x00020000U) #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */ +#ifdef CONFIG_SLAB_OBJ_EXT +/* Slab created using create_boot_cache */ +#define SLAB_NO_OBJ_EXT ((slab_flags_t __force)0x20000000U) +#else +#define SLAB_NO_OBJ_EXT 0 +#endif + /* * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests. *
diff --git a/mm/slab.c b/mm/slab.c
index 10e96137b44f..ba97aeef7ec1 100644
--- a/mm/slab.c
+++ b/mm/slab.c@@ -1233,7 +1233,7 @@ void __init kmem_cache_init(void) create_boot_cache(kmem_cache, "kmem_cache", offsetof(struct kmem_cache, node) + nr_node_ids * sizeof(struct kmem_cache_node *), - SLAB_HWCACHE_ALIGN, 0, 0); + SLAB_HWCACHE_ALIGN | SLAB_NO_OBJ_EXT, 0, 0); list_add(&kmem_cache->list, &slab_caches); slab_state = PARTIAL;
diff --git a/mm/slub.c b/mm/slub.c
index 862dbd9af4f5..80199d5ac7c9 100644
--- a/mm/slub.c
+++ b/mm/slub.c@@ -4825,7 +4825,8 @@ void __init kmem_cache_init(void) node_set(node, slab_nodes); create_boot_cache(kmem_cache_node, "kmem_cache_node", - sizeof(struct kmem_cache_node), SLAB_HWCACHE_ALIGN, 0, 0); + sizeof(struct kmem_cache_node), + SLAB_HWCACHE_ALIGN | SLAB_NO_OBJ_EXT, 0, 0); register_hotmemory_notifier(&slab_memory_callback_nb);
@@ -4835,7 +4836,7 @@ void __init kmem_cache_init(void) create_boot_cache(kmem_cache, "kmem_cache", offsetof(struct kmem_cache, node) + nr_node_ids * sizeof(struct kmem_cache_node *), - SLAB_HWCACHE_ALIGN, 0, 0); + SLAB_HWCACHE_ALIGN | SLAB_NO_OBJ_EXT, 0, 0); kmem_cache = bootstrap(&boot_kmem_cache); kmem_cache_node = bootstrap(&boot_kmem_cache_node);
--
2.37.2.672.g94769d06f0-goog