Re: lock-up with module: Optimize __module_address() using a latched RB-tree

From	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Newsgroups	linux.kernel
Subject	Re: lock-up with module: Optimize __module_address() using a latched RB-tree
Date	2015-07-07 18:40 +0200
Message-ID	<pJE4B-7Yw-101@gated-at.bofh.it> (permalink)
References	(1 earlier) <pJbvA-6OB-9@gated-at.bofh.it> <pJbFg-6Su-11@gated-at.bofh.it> <pJbYB-6Zy-7@gated-at.bofh.it> <pJtLQ-1w8-3@gated-at.bofh.it> <pJvDY-2Dz-23@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

[Multipart message — attachments visible in raw view] - view raw

----- On Jul 7, 2015, at 3:29 AM, Peter Zijlstra peterz@infradead.org wrote:

> On Tue, Jul 07, 2015 at 02:59:06PM +0930, Arthur Marsh wrote:
>> I had a single, non-reproducible case of the same lock-up happening on my
>> other machine running the Linus git head kernel in 64-bit mode.
> 
> Hmm, disturbing.. I've had my machines run this stuff for weeks and not
> had anything like this :/
> 
> Do you have a serial cable between those machines? serial console output
> will allow capturing more complete traces than these pictures can and
> might also aid in capturing some extra debug info.
> 
> In any case, I'll go try and build some debug code.

Arthur: can you double-check if you load any module with --force ?
This could cause a module header layout mismatch, which can be an
issue with the changes done by the identified commit: the module
header layout changes there.

Also, I'm attaching a small patch which serializes both updates and
reads of the module rbree. Can you try it out ? If the problem
still shows with the spinlocks in place, that would mean the issue
is *not* a race between latched rbtree updates and traversals.

Thanks!

Mathieu

-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com

Back to linux.kernel | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

Re: lock-up with module: Optimize __module_address() using a  latched RB-tree Mathieu Desnoyers <mathieu.desnoyers@efficios.com> - 2015-07-07 18:40 +0200
  Re: lock-up with module: Optimize __module_address() using a latched  RB-tree Peter Zijlstra <peterz@infradead.org> - 2015-07-08 14:40 +0200
    [PATCH] module: Fix load_module() error path Peter Zijlstra <peterz@infradead.org> - 2015-07-08 14:50 +0200

csiph-web