From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: sergey.senozhatsky.work@gmail.com,
Dmitry Safonov <dima@arista.com>,
longman@redhat.com, Thomas Gleixner <tglx@linutronix.de>,
Andrew Morton <akpm@linux-foundation.org>,
open list <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
yang.shi@linux.alibaba.com, Arnd Bergmann <arnd@arndb.de>
Subject: Re: [PATCH] debugobjects: Move printk out of db lock critical sections
Date: Thu, 13 Dec 2018 18:00:27 +0900 [thread overview]
Message-ID: <20181213090026.GA7278@jagdpanzerIV> (raw)
In-Reply-To: <CAJwJo6YZNtdsQuGyk6=YDj9QzvktfYeNc5FTi-qw5ttQDVoJ0w@mail.gmail.com>
On (12/13/18 05:54), Dmitry Safonov wrote:
> > I thought about it for a second, but couldn't figure out if this race
> > was real.
> >
> > E.g. uart case - if there are two paths which concurrently free and
> > access debug object, then the same race condition should exist for
> > the xmit.buf page. debug object's lifespan should be the same as the
> > lifespan of, ummm, whatever the thing that debug object is attached
> > to? I'm surely missing something here.
>
> I think the point of debugobjects is to reduce the damage caused
> by an improper life-time of objects.
>
> IIUC:
> 1. alloc_page()
> 2. dynamically allocate a workqueue on a new page
> 3. schedule some work
> 4. until the work has run free_page()
Hmm, if we free() that page then __debug_check_no_obj_freed() should ->fixup
all ODEBUG_STATE_ACTIVE objects first. Maybe we are talking about different
scenarios.
-ss
next prev parent reply other threads:[~2018-12-13 9:00 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-12 22:28 [PATCH] debugobjects: Move printk out of db lock critical sections Waiman Long
2018-12-12 23:39 ` Andrew Morton
2018-12-13 22:01 ` Waiman Long
2018-12-13 2:03 ` Sergey Senozhatsky
2018-12-13 19:59 ` Waiman Long
2018-12-13 2:59 ` Sergey Senozhatsky
2018-12-13 9:21 ` Peter Zijlstra
2018-12-13 4:35 ` Dmitry Safonov
2018-12-13 5:18 ` Sergey Senozhatsky
2018-12-13 5:54 ` Dmitry Safonov
2018-12-13 9:00 ` Sergey Senozhatsky [this message]
2018-12-13 22:10 ` Waiman Long
2018-12-14 18:06 ` Dmitry Safonov
2018-12-14 18:21 ` Waiman Long
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=20181213090026.GA7278@jagdpanzerIV \
--to=sergey.senozhatsky.work@gmail.com \
--cc=0x7f454c46@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=arnd@arndb.de \
--cc=dima@arista.com \
--cc=linux-kernel@vger.kernel.org \
--cc=longman@redhat.com \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=yang.shi@linux.alibaba.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