linux-kernel - Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount

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: Windows password security audit tool. GUI, reports in PDF.

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

Date:   Wed, 22 Mar 2017 08:22:27 -0700
From:   Eric Dumazet <eric.dumazet@...il.com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     Kees Cook <keescook@...omium.org>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        David Miller <davem@...emloft.net>,
        "Reshetova, Elena" <elena.reshetova@...el.com>,
        Network Development <netdev@...r.kernel.org>,
        bridge@...ts.linux-foundation.org,
        LKML <linux-kernel@...r.kernel.org>,
        Alexey Kuznetsov <kuznet@....inr.ac.ru>,
        James Morris <jmorris@...ei.org>,
        Patrick McHardy <kaber@...sh.net>,
        Stephen Hemminger <stephen@...workplumber.org>,
        Hans Liljestrand <ishkamiel@...il.com>,
        David Windsor <dwindsor@...il.com>,
        Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to
 refcount_t

On Wed, 2017-03-22 at 16:08 +0100, Peter Zijlstra wrote:
> On Wed, Mar 22, 2017 at 07:54:04AM -0700, Eric Dumazet wrote:
> > On Wed, 2017-03-22 at 15:33 +0100, Peter Zijlstra wrote:
> > 
> > > 
> > > But I would feel a whole lot better about the entire thing if we could
> > > measure their impact. It would also give us good precedent to whack
> > > other potential users of _nocheck over the head with -- show numbers.
> > 
> > I wont be able to measure the impact on real workloads, our productions
> > kernels are based on 4.3 at this moment.
> 
> Is there really no micro bench that exercises the relevant network
> paths? Do you really fully rely on Google production workloads?

You could run a synflood test, with ~10 Mpps.

sock_hold() is definitely used in SYN handling.

Last upstream kernels do not work on my lab hosts, for whatever reason.