From: Stephen Hemminger <stephen@networkplumber.org>
To: Shaohua Li <shli@kernel.org>
Cc: netdev@vger.kernel.org, davem@davemloft.net, Kernel-team@fb.com,
Shaohua Li <shli@fb.com>, Wei Wang <weiwan@google.com>
Subject: Re: [RFC net-next] net ipv6: convert fib6_table rwlock to a percpu lock
Date: Tue, 1 Aug 2017 07:45:28 -0700 [thread overview]
Message-ID: <20170801074528.289fc520@xeon-e3> (raw)
In-Reply-To: <20170801025704.fuhxll23d3eenwrz@kernel.org>
On Mon, 31 Jul 2017 19:57:04 -0700
Shaohua Li <shli@kernel.org> wrote:
> On Mon, Jul 31, 2017 at 04:10:07PM -0700, Stephen Hemminger wrote:
> > On Mon, 31 Jul 2017 10:18:57 -0700
> > Shaohua Li <shli@kernel.org> wrote:
> >
> > > From: Shaohua Li <shli@fb.com>
> > >
> > > In a syn flooding test, the fib6_table rwlock is a significant
> > > bottleneck. While converting the rwlock to rcu sounds straighforward,
> > > but is very challenging if it's possible. A percpu spinlock is quite
> > > trival for this problem since updating the routing table is a rare
> > > event. In my test, the server receives around 1.5 Mpps in syn flooding
> > > test without the patch in a dual sockets and 56-CPU system. With the
> > > patch, the server receives around 3.8Mpps, and perf report doesn't show
> > > the locking issue.
> > >
> > > Cc: Wei Wang <weiwan@google.com>
> >
> > You just reinvented brlock...
It was a long time ago (2.4) that brlock came in
https://lwn.net/Articles/378781/
I removed it in 2.5.64 or so.
prev parent reply other threads:[~2017-08-01 14:45 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-31 17:18 [RFC net-next] net ipv6: convert fib6_table rwlock to a percpu lock Shaohua Li
2017-07-31 18:30 ` Eric Dumazet
2017-07-31 19:34 ` Shaohua Li
2017-07-31 21:20 ` [net ipv6] ee57005022: WARNING:at_kernel/softirq.c:#__local_bh_enable_ip kernel test robot
2017-07-31 23:10 ` [RFC net-next] net ipv6: convert fib6_table rwlock to a percpu lock Stephen Hemminger
2017-08-01 2:57 ` Shaohua Li
2017-08-01 7:15 ` Eric Dumazet
2017-08-01 14:45 ` Stephen Hemminger [this message]
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