BPF Archive on lore.kernel.org
 help / color / Atom feed
From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
To: "Toke Høiland-Jørgensen" <toke@redhat.com>
Cc: "Network Development" <netdev@vger.kernel.org>,
	bpf <bpf@vger.kernel.org>,
	"Daniel Borkmann" <daniel@iogearbox.net>,
	"Alexei Starovoitov" <ast@kernel.org>,
	"David Miller" <davem@davemloft.net>,
	"Jesper Dangaard Brouer" <brouer@redhat.com>,
	"Björn Töpel" <bjorn.topel@gmail.com>,
	"John Fastabend" <john.fastabend@gmail.com>,
	"Maciej Fijalkowski" <maciej.fijalkowski@intel.com>
Subject: Re: [PATCH bpf-next v3 0/3] xdp: Introduce bulking for non-map XDP_REDIRECT
Date: Thu, 16 Jan 2020 20:06:55 -0800
Message-ID: <CAADnVQJNJ4G2NGGAOe-khAgT2UUE3WxcP2FgT-4Ep9G0afpVfA@mail.gmail.com> (raw)
In-Reply-To: <157918768284.1458396.8128704597152008763.stgit@toke.dk>

On Thu, Jan 16, 2020 at 7:14 AM Toke Høiland-Jørgensen <toke@redhat.com> wrote:
>
> Since commit 96360004b862 ("xdp: Make devmap flush_list common for all map
> instances"), devmap flushing is a global operation instead of tied to a
> particular map. This means that with a bit of refactoring, we can finally fix
> the performance delta between the bpf_redirect_map() and bpf_redirect() helper
> functions, by introducing bulking for the latter as well.
>
> This series makes this change by moving the data structure used for the bulking
> into struct net_device itself, so we can access it even when there is not
> devmap. Once this is done, moving the bpf_redirect() helper to use the bulking
> mechanism becomes quite trivial, and brings bpf_redirect() up to the same as
> bpf_redirect_map():
>
>                        Before:   After:
> 1 CPU:
> bpf_redirect_map:      8.4 Mpps  8.4 Mpps  (no change)
> bpf_redirect:          5.0 Mpps  8.4 Mpps  (+68%)
> 2 CPUs:
> bpf_redirect_map:     15.9 Mpps  16.1 Mpps  (+1% or ~no change)
> bpf_redirect:          9.5 Mpps  15.9 Mpps  (+67%)
>
> After this patch series, the only semantics different between the two variants
> of the bpf() helper (apart from the absence of a map argument, obviously) is
> that the _map() variant will return an error if passed an invalid map index,
> whereas the bpf_redirect() helper will succeed, but drop packets on
> xdp_do_redirect(). This is because the helper has no reference to the calling
> netdev, so unfortunately we can't do the ifindex lookup directly in the helper.
>
> Changelog:
>
> v3:
>   - Switch two more fields to avoid a list_head spanning two cache lines
>   - Include Jesper's tracepoint patch
>   - Also rename xdp_do_flush_map()
>   - Fix a few nits from Maciej

Applied. Thanks

      parent reply index

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-16 15:14 Toke Høiland-Jørgensen
2020-01-16 15:14 ` [PATCH bpf-next v3 1/3] xdp: Move devmap bulk queue into struct net_device Toke Høiland-Jørgensen
2020-01-16 15:14 ` [PATCH bpf-next v3 2/3] xdp: Use bulking for non-map XDP_REDIRECT and consolidate code paths Toke Høiland-Jørgensen
2020-01-16 15:14 ` [PATCH bpf-next v3 3/3] devmap: Adjust tracepoint for map-less queue flush Toke Høiland-Jørgensen
2020-01-17  4:06 ` Alexei Starovoitov [this message]

Reply instructions:

You may reply publically 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=CAADnVQJNJ4G2NGGAOe-khAgT2UUE3WxcP2FgT-4Ep9G0afpVfA@mail.gmail.com \
    --to=alexei.starovoitov@gmail.com \
    --cc=ast@kernel.org \
    --cc=bjorn.topel@gmail.com \
    --cc=bpf@vger.kernel.org \
    --cc=brouer@redhat.com \
    --cc=daniel@iogearbox.net \
    --cc=davem@davemloft.net \
    --cc=john.fastabend@gmail.com \
    --cc=maciej.fijalkowski@intel.com \
    --cc=netdev@vger.kernel.org \
    --cc=toke@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

BPF Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/bpf/0 bpf/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 bpf bpf/ https://lore.kernel.org/bpf \
		bpf@vger.kernel.org
	public-inbox-index bpf

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.bpf


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git