On Tue, 2014-03-11 at 17:02 -0400, Sasha Levin wrote: > On 03/11/2014 04:47 PM, Davidlohr Bueso wrote: > >> Bingo! With the above patch: > >> > > >> >[ 243.565794] kernel BUG at mm/vmacache.c:76! > >> >[ 243.566720] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC > >> >[ 243.568048] Dumping ftrace buffer: > >> >[ 243.568740] (ftrace buffer empty) > >> >[ 243.569481] Modules linked in: > >> >[ 243.570203] CPU: 10 PID: 10073 Comm: trinity-c332 Tainted: G W 3.14.0-rc5-next-20140307-sasha-00010-g1f812cb-dirty #143 > > and this is also part of the DEBUG_PAGEALLOC + trinity combo! I suspect > > the root cause it the same as Fengguang's report. > > The BUG still happens without DEBUG_PAGEALLOC. Any idea what trinity itself is doing? Could you add the following, I just want to make sure the bug isn't being caused by an overflow: diff --git a/mm/vmacache.c b/mm/vmacache.c index add3162..abb85cc 100644 --- a/mm/vmacache.c +++ b/mm/vmacache.c @@ -17,6 +17,8 @@ void vmacache_flush_all(struct mm_struct *mm) { struct task_struct *g, *p; + WARN_ON_ONCE(1); + rcu_read_lock(); for_each_process_thread(g, p) { /* Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>