From: Stephen Hemminger <stephen@networkplumber•org>
To: Thomas Gleixner <tglx@linutronix•de>
Cc: "Ahmed S. Darwish" <a.darwish@linutronix•de>,
Peter Zijlstra <peterz@infradead•org>,
Ingo Molnar <mingo@redhat•com>, Will Deacon <will@kernel•org>,
"Paul E. McKenney" <paulmck@kernel•org>,
"Sebastian A. Siewior" <bigeasy@linutronix•de>,
Steven Rostedt <rostedt@goodmis•org>,
LKML <linux-kernel@vger•kernel.org>,
"David S. Miller" <davem@davemloft•net>,
Jakub Kicinski <kuba@kernel•org>,
netdev@vger•kernel.org
Subject: Re: [PATCH v1 01/25] net: core: device_rename: Use rwsem instead of a seqcount
Date: Tue, 19 May 2020 17:06:37 -0700 [thread overview]
Message-ID: <20200519170637.56d1a20a@hermes.lan> (raw)
In-Reply-To: <87lfln5w61.fsf@nanos.tec.linutronix.de>
On Wed, 20 May 2020 01:42:30 +0200
Thomas Gleixner <tglx@linutronix•de> wrote:
> Stephen Hemminger <stephen@networkplumber•org> writes:
> > On Wed, 20 May 2020 00:23:48 +0200
> > Thomas Gleixner <tglx@linutronix•de> wrote:
> >> No. We did not. -ENOTESTCASE
> >
> > Please try, it isn't that hard..
> >
> > # time for ((i=0;i<1000;i++)); do ip li add dev dummy$i type dummy; done
> >
> > real 0m17.002s
> > user 0m1.064s
> > sys 0m0.375s
>
> And that solves the incorrectness of the current code in which way?
Agree that the current code is has evolved over time to a state where it is not
correct in the case of Preempt-RT. The motivation for the changes to seqcount
goes back many years when there were ISP's that were concerned about scaling of tunnels, vlans etc.
Is it too much to ask for a simple before/after test of your patch as part
of the submission. You probably measure latency changes to the nanosecond.
Getting it correct without causing user complaints.
next prev parent reply other threads:[~2020-05-20 0:06 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-19 21:45 [PATCH v1 00/25] seqlock: Extend seqcount API with associated locks Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 01/25] net: core: device_rename: Use rwsem instead of a seqcount Ahmed S. Darwish
2020-05-19 22:01 ` Stephen Hemminger
2020-05-19 22:23 ` Thomas Gleixner
2020-05-19 23:11 ` Stephen Hemminger
2020-05-19 23:42 ` Thomas Gleixner
2020-05-20 0:06 ` Stephen Hemminger [this message]
2020-05-20 1:55 ` Thomas Gleixner
2020-05-20 2:57 ` David Miller
2020-05-20 3:18 ` Eric Dumazet
2020-05-20 4:36 ` Stephen Hemminger
2020-05-20 19:37 ` Thomas Gleixner
2020-05-20 21:36 ` Stephen Hemminger
2020-05-20 2:01 ` Eric Dumazet
2020-05-20 6:42 ` Ahmed S. Darwish
2020-05-20 12:51 ` Eric Dumazet
2020-06-03 14:33 ` Ahmed S. Darwish
2020-05-20 14:37 ` Dan Carpenter
2020-05-25 16:22 ` Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 03/25] net: phy: fixed_phy: Remove unused seqcount Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 05/25] u64_stats: Document writer non-preemptibility requirement Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 15/25] netfilter: conntrack: Use sequence counter with associated spinlock Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 16/25] netfilter: nft_set_rbtree: Use sequence counter with associated rwlock Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 17/25] xfrm: policy: Use sequence counters with associated lock Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 00/18] seqlock: Extend seqcount API with associated locks Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 08/18] netfilter: conntrack: Use sequence counter with associated spinlock Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 09/18] netfilter: nft_set_rbtree: Use sequence counter with associated rwlock Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 10/18] xfrm: policy: Use sequence counters with associated lock Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 00/20] seqlock: Extend seqcount API with associated locks Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 10/20] netfilter: conntrack: Use sequence counter with associated spinlock Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 11/20] netfilter: nft_set_rbtree: Use sequence counter with associated rwlock Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 12/20] xfrm: policy: Use sequence counters with associated lock Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 00/24] seqlock: Extend seqcount API with associated locks Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 14/24] netfilter: conntrack: Use sequence counter with associated spinlock Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 15/24] netfilter: nft_set_rbtree: Use sequence counter with associated rwlock Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 16/24] xfrm: policy: Use sequence counters with associated lock Ahmed S. Darwish
2020-07-20 16:49 ` [PATCH v4 00/24] seqlock: Extend seqcount API with associated locks Eric Biggers
2020-07-20 17:33 ` Ahmed S. Darwish
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=20200519170637.56d1a20a@hermes.lan \
--to=stephen@networkplumber$(echo .)org \
--cc=a.darwish@linutronix$(echo .)de \
--cc=bigeasy@linutronix$(echo .)de \
--cc=davem@davemloft$(echo .)net \
--cc=kuba@kernel$(echo .)org \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=mingo@redhat$(echo .)com \
--cc=netdev@vger$(echo .)kernel.org \
--cc=paulmck@kernel$(echo .)org \
--cc=peterz@infradead$(echo .)org \
--cc=rostedt@goodmis$(echo .)org \
--cc=tglx@linutronix$(echo .)de \
--cc=will@kernel$(echo .)org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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