From: "Toke Høiland-Jørgensen" <toke@redhat.com>
To: "Maciej Żenczykowski" <maze@google.com>,
"Jesper Dangaard Brouer" <brouer@redhat.com>
Cc: Jakub Kicinski <kuba@kernel.org>, bpf <bpf@vger.kernel.org>,
Linux NetDev <netdev@vger.kernel.org>,
Daniel Borkmann <borkmann@iogearbox.net>,
Alexei Starovoitov <alexei.starovoitov@gmail.com>,
John Fastabend <john.fastabend@gmail.com>
Subject: Re: [PATCH bpf-next] bpf: don't check against device MTU in __bpf_skb_max_len
Date: Tue, 15 Sep 2020 10:47:36 +0200 [thread overview]
Message-ID: <87ft7jzas7.fsf@toke.dk> (raw)
In-Reply-To: <CANP3RGftg2-_tBc=hGGzxjGZUq9b1amb=TiKRVHSBEyXq-A5QA@mail.gmail.com>
[ just jumping in to answer this bit: ]
> Would you happen to know what ebpf startup overhead is?
> How big a problem is having two (or more) back to back tc programs
> instead of one?
With a jit'ed BPF program and the in-kernel dispatcher code (which
avoids indirect calls), it's quite close to a native function call.
> We're running into both verifier performance scaling problems and code
> ownership issues with large programs...
>
> [btw. I understand for XDP we could only use 1 program anyway...]
Working on that! See my talk at LPC:
https://linuxplumbersconf.org/event/7/contributions/671/
Will post a follow-up to the list once the freplace multi-attach series
lands.
-Toke
next prev parent reply other threads:[~2020-09-15 8:47 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-04 9:30 [PATCH bpf-next] bpf: don't check against device MTU in __bpf_skb_max_len Jesper Dangaard Brouer
2020-09-04 23:39 ` Jakub Kicinski
2020-09-07 14:07 ` Jesper Dangaard Brouer
2020-09-10 20:00 ` Maciej Żenczykowski
2020-09-14 14:05 ` Jesper Dangaard Brouer
2020-09-14 20:50 ` Maciej Żenczykowski
2020-09-15 8:47 ` Toke Høiland-Jørgensen [this message]
2020-09-16 0:12 ` Maciej Żenczykowski
2020-09-16 11:37 ` Toke Høiland-Jørgensen
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