[merged] memcg-fix-mem_cgroup_print_bad_page.patch removed from -mm tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



The patch titled
     Subject: memcg: fix mem_cgroup_print_bad_page
has been removed from the -mm tree.  Its filename was
     memcg-fix-mem_cgroup_print_bad_page.patch

This patch was dropped because it was merged into mainline or a subsystem tree

The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/

------------------------------------------------------
From: Hugh Dickins <hughd@xxxxxxxxxx>
Subject: memcg: fix mem_cgroup_print_bad_page

If DEBUG_VM, mem_cgroup_print_bad_page() is called whenever bad_page()
shows a "Bad page state" message, removes page from circulation, adds a
taint and continues.  This is at a very low level, often when a spinlock
is held (sometimes when page table lock is held, for example).

We want to recover from this badness, not make it worse: we must not
kmalloc memory here, we must not do a cgroup path lookup via dubious
pointers.  No doubt that code was useful to debug a particular case at one
time, and may be again, but take it out of the mainline kernel.

Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 mm/memcontrol.c |   17 +----------------
 1 file changed, 1 insertion(+), 16 deletions(-)

diff -puN mm/memcontrol.c~memcg-fix-mem_cgroup_print_bad_page mm/memcontrol.c
--- a/mm/memcontrol.c~memcg-fix-mem_cgroup_print_bad_page
+++ a/mm/memcontrol.c
@@ -3364,23 +3364,8 @@ void mem_cgroup_print_bad_page(struct pa
 
 	pc = lookup_page_cgroup_used(page);
 	if (pc) {
-		int ret = -1;
-		char *path;
-
-		printk(KERN_ALERT "pc:%p pc->flags:%lx pc->mem_cgroup:%p",
+		printk(KERN_ALERT "pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
 		       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_CONT "(%s)\n",
-				(ret < 0) ? "cannot get the path" : path);
-		kfree(path);
 	}
 }
 #endif
_

Patches currently in -mm which might be from hughd@xxxxxxxxxx are

origin.patch
linux-next.patch
prio_tree-debugging-patch.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


[Index of Archives]     [Kernel Newbies FAQ]     [Kernel Archive]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [Bugtraq]     [Photo]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]

  Powered by Linux