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Date:   Tue, 23 Jun 2020 15:11:45 -0700 (PDT)
Message-Id: <20200623.151145.1336624346097080182.davem@davemloft.net>
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Subject: Re: [PATCH v2 net-next 2/2] ipv6: fib6: avoid indirect calls from
 fib6_rule_lookup
From:   David Miller <davem@davemloft.net>
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From: Brian Vazquez <brianvv@google.com>
Date: Tue, 23 Jun 2020 09:42:32 -0700

> It was reported that a considerable amount of cycles were spent on the
> expensive indirect calls on fib6_rule_lookup. This patch introduces an
> inline helper called pol_route_func that uses the indirect_call_wrappers
> to avoid the indirect calls.
> 
> This patch saves around 50ns per call.
> 
> Performance was measured on the receiver by checking the amount of
> syncookies that server was able to generate under a synflood load.
> 
> Traffic was generated using trafgen[1] which was pushing around 1Mpps on
> a single queue. Receiver was using only one rx queue which help to
> create a bottle neck and make the experiment rx-bounded.
> 
> These are the syncookies generated over 10s from the different runs:
> 
> Whithout the patch:
 ...
> With the patch:
 ...
> Without the patch the average is 354263 pkt/s or 2822 ns/pkt and with
> the patch the average is 360738 pkt/s or 2772 ns/pkt which gives an
> estimate of 50 ns per packet.
> 
> [1] http://netsniff-ng.org/
> 
> Changelog since v1:
>  - Change ordering in the ICW (Paolo Abeni)
> 
> Cc: Luigi Rizzo <lrizzo@google.com>
> Cc: Paolo Abeni <pabeni@redhat.com>
> Reported-by: Eric Dumazet <edumazet@google.com>
> Signed-off-by: Brian Vazquez <brianvv@google.com>

Applied.