netdev - Re: iproute2: tc deletion freezes whole server

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CANxWus-koY-AHzqbdG6DaVaDYj4aWztj8m+8ntYLvEQ0iM_yDw@mail.gmail.com>
Date:   Wed, 25 Mar 2020 19:23:54 +0100
From:   Václav Zindulka <vaclav.zindulka@...pnet.cz>
To:     Cong Wang <xiyou.wangcong@...il.com>
Cc:     Linux Kernel Network Developers <netdev@...r.kernel.org>
Subject: Re: iproute2: tc deletion freezes whole server

On Wed, Mar 25, 2020 at 6:43 PM Cong Wang <xiyou.wangcong@...il.com> wrote:
>
> On Wed, Mar 25, 2020 at 4:28 AM Václav Zindulka
> <vaclav.zindulka@...pnet.cz> wrote:
> >
> > On Tue, Mar 24, 2020 at 11:57 PM Cong Wang <xiyou.wangcong@...il.com> wrote:
> > > Hm, my bad, please also run `perf report -g` after you record them,
> > > we need the text output with stack traces.
> >
> > No problem. I've created reports on two servers with different cards.
> > See here https://github.com/zvalcav/tc-kernel/tree/master/20200325
>
> That is great!
>
> Your kernel log does not show anything useful, so it did not lead to
> any kernel hang or crash etc. at all. (This also means you do not need
> to try kdump.)

Ok.

>
> Are you able to test an experimental patch attached in this email?

Sure. I'll compile new kernel tomorrow. Thank you for quick patch.
I'll let you know as soon as I have anything.

> It looks like your kernel spent too much time in fq_codel_reset(),
> most of it are unnecessary as it is going to be destroyed right after
> resetting.

Yeah, I noticed it too.

> Note: please do not judge the patch, it is merely for testing purpose.
> It is obviously ugly and is only a proof of concept. A complete one
> should be passing a boolean parameter down to each ->reset(),
> but it would be much larger.

No judging at all. I totally understand this as prototype ;-)

>
> Thanks for testing!

I thank you! It may allow me to finally deploy a year of my work time.