From ff7ee93f47151e23601856e7eb5510babf956571 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Nov 2011 13:38:11 -0700 Subject: [PATCH] cgroup/kmemleak: Annotate alloc_page() for cgroup allocations When the cgroup base was allocated with kmalloc, it was necessary to annotate the variable with kmemleak_not_leak(). But because it has recently been changed to be allocated with alloc_page() (which skips kmemleak checks) causes a warning on boot up. I was triggering this output: allocated 8388608 bytes of page_cgroup please try 'cgroup_disable=memory' option if you don't want memory cgroups kmemleak: Trying to color unknown object at 0xf5840000 as Grey Pid: 0, comm: swapper Not tainted 3.0.0-test #12 Call Trace: [] ? printk+0x1d/0x1f^M [] paint_ptr+0x4f/0x78 [] kmemleak_not_leak+0x58/0x7d [] ? __rcu_read_unlock+0x9/0x7d [] kmemleak_init+0x19d/0x1e9 [] start_kernel+0x346/0x3ec [] ? loglevel+0x18/0x18 [] i386_start_kernel+0xaa/0xb0 After a bit of debugging I tracked the object 0xf840000 (and others) down to the cgroup code. The change from allocating base with kmalloc to alloc_page() has the base not calling kmemleak_alloc() which adds the pointer to the object_tree_root, but kmemleak_not_leak() adds it to the crt_early_log[] table. On kmemleak_init(), the entry is found in the early_log[] but not the object_tree_root, and this error message is displayed. If alloc_page() fails then it defaults back to vmalloc() which still uses the kmemleak_alloc() which makes us still need the kmemleak_not_leak() call. The solution is to call the kmemleak_alloc() directly if the alloc_page() succeeds. Reviewed-by: Michal Hocko Signed-off-by: Steven Rostedt Acked-by: Catalin Marinas Signed-off-by: Jonathan Nieder Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_cgroup.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c index 6bdc67dbbc28..3749ae15a8c8 100644 --- a/mm/page_cgroup.c +++ b/mm/page_cgroup.c @@ -133,10 +133,13 @@ struct page *lookup_cgroup_page(struct page_cgroup *pc) static void *__meminit alloc_page_cgroup(size_t size, int nid) { void *addr = NULL; + gfp_t flags = GFP_KERNEL | __GFP_NOWARN; - addr = alloc_pages_exact_nid(nid, size, GFP_KERNEL | __GFP_NOWARN); - if (addr) + addr = alloc_pages_exact_nid(nid, size, flags); + if (addr) { + kmemleak_alloc(addr, size, 1, flags); return addr; + } if (node_state(nid, N_HIGH_MEMORY)) addr = vmalloc_node(size, nid); -- 2.20.1