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: Mon, 31 Jul 2017 16:10:07 -0700 [thread overview]
Message-ID: <20170731161007.61c2d958@xeon-e3> (raw)
In-Reply-To: <1a5ad2f0585aa66496b27e123d1c38b75552df4c.1501520674.git.shli@fb.com>
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...
RCU is not that hard, why not do it right?
next prev parent reply other threads:[~2017-07-31 23:10 UTC|newest]
Thread overview: 9+ 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 21:20 ` kernel test robot
2017-07-31 23:10 ` Stephen Hemminger [this message]
2017-08-01 2:57 ` [RFC net-next] net ipv6: convert fib6_table rwlock to a percpu lock Shaohua Li
2017-08-01 7:15 ` Eric Dumazet
2017-08-01 14:45 ` Stephen Hemminger
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