From: Florian Westphal <fw@strlen.de>
To: "Major Dávid" <major.david@balasys.hu>
Cc: Florian Westphal <fw@strlen.de>,
netfilter-devel@vger.kernel.org,
Pablo Neira Ayuso <pablo@netfilter.org>
Subject: Re: CPU soft lockup in a spin lock using tproxy and nfqueue
Date: Fri, 3 Mar 2023 01:09:26 +0100 [thread overview]
Message-ID: <20230303000926.GC9239@breakpoint.cc> (raw)
In-Reply-To: <f8d03b81-8980-b54e-a2a3-57f8e54044be@balasys.hu>
Major Dávid <major.david@balasys.hu> wrote:
> Thanks,
>
> I builded and tested in my Jammy environment, and I could not reproduce
> any soft lockups with this patch anymore.
Thanks.
> But I am also wondering that the inet_twsk_deschedule_put is really
> needed in this particular case in tproxy? As I understand it, there
> is an other independent mechanism which destroys tw sockets, so no
> need do it here?
Which one? As far as I can see TCP stack would end up adding a
duplicate quadruple to the hash if we only drop the reference and
keep the listen sk around.
And if we assign the tw socket to the skb TCP stack might not be able
to find the correct listener if the service is on a different port
than what is in the TCP header.
Did I miss anything?
next prev parent reply other threads:[~2023-03-03 0:09 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-02 13:26 CPU soft lockup in a spin lock using tproxy and nfqueue Major Dávid
2023-03-02 14:29 ` Florian Westphal
2023-03-02 16:06 ` Major Dávid
2023-03-03 0:09 ` Florian Westphal [this message]
2023-03-03 9:23 ` Major Dávid
2023-03-03 9:33 ` Florian Westphal
2023-03-03 9:41 ` Major Dávid
2023-03-03 9:45 ` Florian Westphal
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=20230303000926.GC9239@breakpoint.cc \
--to=fw@strlen.de \
--cc=major.david@balasys.hu \
--cc=netfilter-devel@vger.kernel.org \
--cc=pablo@netfilter.org \
/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