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McKenney" , Frederic Weisbecker , Neeraj Upadhyay , Joel Fernandes , Uladzislau Rezki , rcu@vger.kernel.org Subject: Re: [RFC PATCH 0/8] Introduce simple hazard pointers for lockdep Message-ID: References: <20250414060055.341516-1-boqun.feng@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250414060055.341516-1-boqun.feng@gmail.com> Hi Boqun, On Sun, Apr 13, 2025 at 11:00:47PM -0700, Boqun Feng wrote: > Overall it looks promising to me, but I would like to see how it > performs in the environment of Breno. Also as Paul always reminds me: > buggy code usually run faster, so please take a look in case I'm missing > something ;-) Thanks! Thanks for the patchset. I've confirmed that the wins are large on my environment, but, at the same magnitute of synchronize_rcu_expedited(). Here are the numbers I got: 6.15-rc1 (upstream) # time /usr/sbin/tc qdisc replace dev eth0 root handle 0x1234: mq real 0m3.986s user 0m0.001s sys 0m0.093s Your patchset on top of 6.15-rc1 # time /usr/sbin/tc qdisc replace dev eth0 root handle 0x1234: mq real 0m0.072s user 0m0.001s sys 0m0.070s My original proposal of using synchronize_rcu_expedited()[1] # time /usr/sbin/tc qdisc replace dev eth0 root handle 0x1234: mq real 0m0.074s user 0m0.001s sys 0m0.061s Link: https://lore.kernel.org/all/20250321-lockdep-v1-1-78b732d195fb@debian.org/ [1] Thanks for working on it, --breno