On Thu, 3 Feb 2011 15:15:33 +0100
Johannes Weiner <hannes@xxxxxxxxxxx> wrote:
> From: Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx>
>
> This patch add checks at allocating or freeing a page whether the page is used
> (iow, charged) from the view point of memcg.
>
> This check may be useful in debugging a problem and we did similar checks
> before the commit 52d4b9ac(memcg: allocate all page_cgroup at boot).
>
> This patch adds some overheads at allocating or freeing memory, so it's enabled
> only when CONFIG_DEBUG_VM is enabled.
>
> Signed-off-by: Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx>
> Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Thank you for picking up this patch. You actually remind me about this patch :)
I have one comment.
> +void mem_cgroup_print_bad_page(struct page *page)
> +{
> + struct page_cgroup *pc;
> +
> + pc = lookup_page_cgroup_used(page);
> + if (pc)
> + printk(KERN_ALERT "pc:%p pc->flags:%ld pc->mem_cgroup:%p\n",
> + pc, pc->flags, pc->mem_cgroup);
> +}
> +#endif
> +
When I posted this patch before, I received a comment that showing the path of
the cgroup would be better.
This is a additional patch to show the path.
===
From: Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx>
Let's try to show the path name of the cgroup too.
Signed-off-by: Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 20 ++++++++++++++++++--
1 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 2ed1b33..3c14d20 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3040,9 +3040,25 @@ void mem_cgroup_print_bad_page(struct page *page)
struct page_cgroup *pc;
pc = lookup_page_cgroup_used(page);
- if (pc)
- printk(KERN_ALERT "pc:%p pc->flags:%ld pc->mem_cgroup:%p\n",
+ if (pc) {
+ int ret = -1;
+ char *path;
+
+ printk(KERN_ALERT "pc:%p pc->flags:%ld pc->mem_cgroup:%p",
pc, pc->flags, pc->mem_cgroup);
+
+ path = kmalloc(PATH_MAX, GFP_KERNEL);
+ if (path) {
+ rcu_read_lock();
+ ret = cgroup_path(pc->mem_cgroup->css.cgroup,
+ path, PATH_MAX);
+ rcu_read_unlock();
+ }
+
+ printk(KERN_ALERT "(%s)\n",
+ (ret < 0) ? "cannot get the path" : path);
+ kfree(path);
+ }
}
#endif
--
1.7.1
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxxx For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>