From: Peter Zijlstra <peterz@infradead.org>
To: Byungchul Park <byungchul.park@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>,
Dmitry Vyukov <dvyukov@google.com>,
syzbot
<bot+e7353c7141ff7cbb718e4c888a14fa92de41ebaa@syzkaller.appspotmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
Dan Williams <dan.j.williams@intel.com>,
Johannes Weiner <hannes@cmpxchg.org>, Jan Kara <jack@suse.cz>,
jglisse@redhat.com, LKML <linux-kernel@vger.kernel.org>,
linux-mm@kvack.org, shli@fb.com, syzkaller-bugs@googlegroups.com,
Thomas Gleixner <tglx@linutronix.de>,
Vlastimil Babka <vbabka@suse.cz>,
ying.huang@intel.com, kernel-team@lge.com
Subject: Re: possible deadlock in lru_add_drain_all
Date: Mon, 30 Oct 2017 16:22:00 +0100 [thread overview]
Message-ID: <20171030152200.ayfnewoqkxbuk4zh@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20171030151009.ip4k7nwan7muouca@hirez.programming.kicks-ass.net>
On Mon, Oct 30, 2017 at 04:10:09PM +0100, Peter Zijlstra wrote:
> I can indeed confirm it's running old code; cpuhp_state is no more.
>
> However, that splat translates like:
>
> __cpuhp_setup_state()
> #0 cpus_read_lock()
> __cpuhp_setup_state_cpuslocked()
> #1 mutex_lock(&cpuhp_state_mutex)
>
>
>
> __cpuhp_state_add_instance()
> #2 mutex_lock(&cpuhp_state_mutex)
> cpuhp_issue_call()
> cpuhp_invoke_ap_callback()
> #3 wait_for_completion()
>
> msr_device_create()
> ...
> #4 filename_create()
> #3 complete()
>
So all this you can get in a single callchain when you do something
shiny like:
modprobe msr
> do_splice()
> #4 file_start_write()
> do_splice_from()
> iter_file_splice_write()
> #5 pipe_lock()
> vfs_iter_write()
> ...
> #6 inode_lock()
>
>
This is a splice into a devtmpfs file
> sys_fcntl()
> do_fcntl()
> shmem_fcntl()
> #5 inode_lock()
#6 (obviously)
> shmem_wait_for_pins()
> if (!scan)
> lru_add_drain_all()
> #0 cpus_read_lock()
>
Is the right fcntl()
So 3 different callchains, and *splat*..
next prev parent reply other threads:[~2017-10-30 15:22 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <089e0825eec8955c1f055c83d476@google.com>
2017-10-27 9:34 ` possible deadlock in lru_add_drain_all Michal Hocko
2017-10-27 9:44 ` Dmitry Vyukov
2017-10-27 9:47 ` Dmitry Vyukov
2017-10-27 13:42 ` Michal Hocko
2017-10-30 8:22 ` Michal Hocko
2017-10-30 10:09 ` Byungchul Park
2017-10-30 15:10 ` Peter Zijlstra
2017-10-30 15:22 ` Peter Zijlstra [this message]
2017-10-31 13:13 ` Michal Hocko
2017-10-31 13:51 ` Peter Zijlstra
2017-10-31 13:55 ` Dmitry Vyukov
2017-10-31 14:52 ` Peter Zijlstra
2017-10-31 14:58 ` Michal Hocko
2017-10-31 15:10 ` Peter Zijlstra
2017-11-01 8:59 ` Byungchul Park
2017-11-01 12:01 ` Peter Zijlstra
2017-11-01 23:54 ` Byungchul Park
2018-02-14 14:01 ` Dmitry Vyukov
2018-02-14 15:44 ` Michal Hocko
2018-02-14 15:57 ` Dmitry Vyukov
2017-10-31 15:25 ` Peter Zijlstra
2017-10-31 15:45 ` Michal Hocko
2017-10-31 16:30 ` Peter Zijlstra
2017-11-01 8:31 ` Byungchul Park
2017-10-30 10:26 ` Byungchul Park
2017-10-30 11:48 ` Michal Hocko
2017-10-27 11:27 ` Vlastimil Babka
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20171030152200.ayfnewoqkxbuk4zh@hirez.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=bot+e7353c7141ff7cbb718e4c888a14fa92de41ebaa@syzkaller.appspotmail.com \
--cc=byungchul.park@lge.com \
--cc=dan.j.williams@intel.com \
--cc=dvyukov@google.com \
--cc=hannes@cmpxchg.org \
--cc=jack@suse.cz \
--cc=jglisse@redhat.com \
--cc=kernel-team@lge.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=shli@fb.com \
--cc=syzkaller-bugs@googlegroups.com \
--cc=tglx@linutronix.de \
--cc=vbabka@suse.cz \
--cc=ying.huang@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).