The patch titled
Subject: cgroup/kmemleak: Annotate alloc_page() for cgroup allocations
has been added to the -mm tree. Its filename is
cgroup-kmemleak-annotate-alloc_page-for-cgroup-allocations.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
From: Steven Rostedt <rostedt@xxxxxxxxxxx>
Subject: 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:
[<c17e34e6>] ? printk+0x1d/0x1f^M
[<c10e2941>] paint_ptr+0x4f/0x78
[<c178ab57>] kmemleak_not_leak+0x58/0x7d
[<c108ae9f>] ? __rcu_read_unlock+0x9/0x7d
[<c1cdb462>] kmemleak_init+0x19d/0x1e9
[<c1cbf771>] start_kernel+0x346/0x3ec
[<c1cbf1b4>] ? loglevel+0x18/0x18
[<c1cbf0aa>] 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 <mhocko@xxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Jonathan Nieder <jrnieder@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxx>
---
mm/page_cgroup.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff -puN mm/page_cgroup.c~cgroup-kmemleak-annotate-alloc_page-for-cgroup-allocations mm/page_cgroup.c
--- a/mm/page_cgroup.c~cgroup-kmemleak-annotate-alloc_page-for-cgroup-allocations
+++ a/mm/page_cgroup.c
@@ -133,10 +133,13 @@ struct page *lookup_cgroup_page(struct p
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);
_
Subject: Subject: cgroup/kmemleak: Annotate alloc_page() for cgroup allocations
Patches currently in -mm which might be from rostedt@xxxxxxxxxxx are
linux-next.patch
stop_machine-make-stop_machine-safe-and-efficient-to-call-early.patch
stop_machine-make-stop_machine-safe-and-efficient-to-call-early-fix.patch
stop_machine-make-stop_machine-safe-and-efficient-to-call-early-fix-fix.patch
cgroup-kmemleak-annotate-alloc_page-for-cgroup-allocations.patch
memcg-fix-race-condition-in-memcg_check_events-with-this_cpu-usage.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
