All of lore.kernel.org
 help / color / mirror / Atom feed
From: Chris Mi <chrism@mellanox.com>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Linux Kernel Network Developers <netdev@vger.kernel.org>,
	Jamal Hadi Salim <jhs@mojatatu.com>,
	Lucas Bates <lucasb@mojatatu.com>, Jiri Pirko <jiri@resnulli.us>,
	David Miller <davem@davemloft.net>
Subject: RE: [patch net v2 1/4] net/sched: Change tc_action refcnt and bindcnt to atomic
Date: Wed, 18 Oct 2017 01:03:31 +0000	[thread overview]
Message-ID: <VI1PR0501MB21437552565B68DC71A7DEE1AB4D0@VI1PR0501MB2143.eurprd05.prod.outlook.com> (raw)
In-Reply-To: <CAM_iQpWbfjCH0EFb8RYnOuZQtVtg-Mw-Kzv3GWq81qTVErN6hA@mail.gmail.com>

> -----Original Message-----
> From: Cong Wang [mailto:xiyou.wangcong@gmail.com]
> Sent: Tuesday, October 17, 2017 11:53 PM
> To: Chris Mi <chrism@mellanox.com>
> Cc: Linux Kernel Network Developers <netdev@vger.kernel.org>; Jamal Hadi
> Salim <jhs@mojatatu.com>; Lucas Bates <lucasb@mojatatu.com>; Jiri Pirko
> <jiri@resnulli.us>; David Miller <davem@davemloft.net>
> Subject: Re: [patch net v2 1/4] net/sched: Change tc_action refcnt and
> bindcnt to atomic
> 
> On Mon, Oct 16, 2017 at 6:14 PM, Chris Mi <chrism@mellanox.com> wrote:
> > I don't think this bug were introduced by above two commits only.
> > Actually, this bug were introduced by several commits, at least the
> following:
> > 1. refcnt and bindcnt are not atomic
> 
> Nope, it is perfectly okay with non-atomic as long as no parallel, and without
> RCU callback they are perfectly serialized by RTNL.
Agree.
> 
> 
> > 2. passing actions using list instead of arrays (I think initially we
> > are using arrays)
> 
> We are discussing patch 1/4, this is patch 2/4, so irrelevant.
Agree.
> 
> 
> > 3. using RCU callbacks
> 
> This introduces problem 1.
I think this patch set only fixes one problem, that's the race and the panic.
What do you mean by problem 1.
> 
> 
> > So instead of blaming the latest commit, it is better to say it is a pre-git error.
> 
> You are wrong.
OK, you are right. But could I know what's your suggestion for this patch set?
1. reject it?
2. change the "Fixes" as you suggested?
3. something else?

Thanks,
Chris

  reply	other threads:[~2017-10-18  1:03 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-10-16 11:18 [patch net v2 0/4] net/sched: Fix a system panic when deleting filters Chris Mi
2017-10-16 11:18 ` [patch net v2 1/4] net/sched: Change tc_action refcnt and bindcnt to atomic Chris Mi
2017-10-16 17:06   ` Cong Wang
2017-10-17  1:14     ` Chris Mi
2017-10-17 15:52       ` Cong Wang
2017-10-18  1:03         ` Chris Mi [this message]
2017-10-18 16:43           ` Cong Wang
2017-10-19 14:21             ` Jamal Hadi Salim
2017-10-20  3:00               ` Cong Wang
2017-10-23  2:47                 ` Chris Mi
2017-10-23 15:39                   ` Cong Wang
2017-10-24  6:17                     ` Chris Mi
2017-10-16 11:18 ` [patch net v2 2/4] net/sched: Use action array instead of action list as parameter Chris Mi
2017-10-16 11:18 ` [patch net v2 3/4] selftests: Introduce a new script to generate tc batch file Chris Mi
2017-10-16 16:24   ` Lucas Bates
2017-10-16 11:18 ` [patch net v2 4/4] selftests: Introduce a new test case to tc testsuite Chris Mi
2017-10-16 16:25   ` Lucas Bates
2017-10-17  1:03     ` Chris Mi

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=VI1PR0501MB21437552565B68DC71A7DEE1AB4D0@VI1PR0501MB2143.eurprd05.prod.outlook.com \
    --to=chrism@mellanox.com \
    --cc=davem@davemloft.net \
    --cc=jhs@mojatatu.com \
    --cc=jiri@resnulli.us \
    --cc=lucasb@mojatatu.com \
    --cc=netdev@vger.kernel.org \
    --cc=xiyou.wangcong@gmail.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.