From:   Thomas Gleixner <tglx@linutronix.de>
To:     Jakub Kicinski <kuba@kernel.org>
Cc:     Eric Dumazet <edumazet@google.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Linus Torvalds <torvalds@linuxfoundation.org>, x86@kernel.org,
        Wangyang Guo <wangyang.guo@intel.com>,
        Arjan van De Ven <arjan@linux.intel.com>,
        "David S. Miller" <davem@davemloft.net>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        Will Deacon <will@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Boqun Feng <boqun.feng@gmail.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Marc Zyngier <maz@kernel.org>
Subject: Re: [patch 0/3] net, refcount: Address dst_entry reference count
 scalability issues
In-Reply-To: <20230228191705.3bc8bed6@kernel.org>
References: <20230228132118.978145284@linutronix.de>
 <CANn89iL2pYt2QA2sS4KkXrCSjprz9byE_p+Geom3MTNPMzfFDw@mail.gmail.com>
 <87h6v5n3su.ffs@tglx>
 <CANn89iL_ey=S=FjkhJ+mk7gabOdVag6ENKnu9GnZkcF31qOaZA@mail.gmail.com>
 <871qm9mgkb.ffs@tglx> <20230228191705.3bc8bed6@kernel.org>
Date:   Wed, 01 Mar 2023 11:40:11 +0100
Message-ID: <87sfeolppw.ffs@tglx>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

On Tue, Feb 28 2023 at 19:17, Jakub Kicinski wrote:
> FWIW looks good to me, especially the refcount part.
> We do see 10% of jitter in microbenchmarks due to random cache
> effects, so forgive the questioning.

Yes, those things are hard to measure. 

> But again, the refcount seems like an obvious win to my noob eyes.
>
> While I have you it would be remiss of me not to mention my ksoftirq
> change which makes a large difference in production workloads:
> https://lore.kernel.org/all/20221222221244.1290833-3-kuba@kernel.org/

Let me find this again.

> Is Peter's "rework" of softirq going in for 6.3?

Not that I'm aware of. That had a few loose ends and got lost in space
AFAICT.

Thanks,

        tglx