Hi XDP-folks,
This two patch series contain two optimizations for the
bpf_redirect_map() helper and the xdp_do_redirect() function.
The bpf_redirect_map() optimization is about avoiding the map lookup
dispatching. Instead of having a switch-statement and selecting the
correct lookup function, we let bpf_redirect_map() be a map operation,
where each map has its own bpf_redirect_map() implementation. This way
the run-time lookup is avoided.
The xdp_do_redirect() patch restructures the code, so that the map
pointer indirection can be avoided.
Performance-wise I got 3% improvement for XSKMAP
(sample:xdpsock/rx-drop), and 4% (sample:xdp_redirect_map) on my
machine.
More details in each commit.
@Jesper/Toke I dropped your Acked-by: on the first patch, since there
were major restucturing. Please have another look! Thanks!
Changelog:
v3->v4: Made bpf_redirect_map() a map operation. (Daniel)
v2->v3: Fix build when CONFIG_NET is not set. (lkp)
v1->v2: Removed warning when CONFIG_BPF_SYSCALL was not set. (lkp)
Cleaned up case-clause in xdp_do_generic_redirect_map(). (Toke)
Re-added comment. (Toke)
rfc->v1: Use map_id, and remove bpf_clear_redirect_map(). (Toke)
Get rid of the macro and use __always_inline. (Jesper)
rfc: https://lore.kernel.org/bpf/87im7fy9nc.fsf@xxxxxxx/ (Cover not on lore!)
v1: https://lore.kernel.org/bpf/20210219145922.63655-1-bjorn.topel@xxxxxxxxx/
v2: https://lore.kernel.org/bpf/20210220153056.111968-1-bjorn.topel@xxxxxxxxx/
v3: https://lore.kernel.org/bpf/20210221200954.164125-3-bjorn.topel@xxxxxxxxx/
Cheers,
Björn
Björn Töpel (2):
bpf, xdp: make bpf_redirect_map() a map operation
bpf, xdp: restructure redirect actions
include/linux/bpf.h | 26 ++----
include/linux/filter.h | 39 +++++++-
include/net/xdp_sock.h | 19 ----
include/trace/events/xdp.h | 66 ++++++++-----
kernel/bpf/cpumap.c | 10 +-
kernel/bpf/devmap.c | 19 +++-
kernel/bpf/verifier.c | 11 ++-
net/core/filter.c | 183 ++++++++++++-------------------------
net/xdp/xskmap.c | 20 +++-
9 files changed, 195 insertions(+), 198 deletions(-)
base-commit: 9c8f21e6f8856a96634e542a58ef3abf27486801
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2.27.0
