Messages in this thread | | | Date | Wed, 27 Jul 2011 09:55:51 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [PATCH v3] cgroup/kmemcheck: Annotate alloc_page() for cgroup allocations |
| |
On Tue, 26 Jul 2011 15:19:16 -0400 Steven Rostedt <rostedt@goodmis.org> wrote:
> When the cgroup base was allocated with kmalloc, it was necessary to > annotate the variable with kmemcheck_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@suse.cz> > Signed-off-by: Steven Rostedt <rostedt@goodmis.org> > Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
| |