lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Tue, 14 Jan 2020 09:47:59 -0800 From: Alexei Starovoitov <alexei.starovoitov@...il.com> To: Toke Høiland-Jørgensen <toke@...hat.com> Cc: Network Development <netdev@...r.kernel.org>, bpf <bpf@...r.kernel.org>, Daniel Borkmann <daniel@...earbox.net>, Alexei Starovoitov <ast@...nel.org>, David Miller <davem@...emloft.net>, Jesper Dangaard Brouer <brouer@...hat.com>, Björn Töpel <bjorn.topel@...il.com>, John Fastabend <john.fastabend@...il.com> Subject: Re: [PATCH bpf-next v2 0/2] xdp: Introduce bulking for non-map XDP_REDIRECT On Mon, Jan 13, 2020 at 10:11 AM Toke Høiland-Jørgensen <toke@...hat.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: > > v2: > - Consolidate code paths and tracepoints for map and non-map redirect variants > (Björn) > - Add performance data for 2-CPU test (Jesper) > - Move fields to avoid shifting cache lines in struct net_device (Eric) John, since you commented on v1 please review this v2. Thanks!
Powered by blists - more mailing lists