Lorenz Bauer de21d8bf77 bpf: Do not invoke the XDP dispatcher for PROG_RUN with single repeat ... We have a unit test that invokes an XDP program with 1m different inputs, aka 1m BPF_PROG_RUN syscalls. We run this test concurrently with slight variations in how we generated the input. Since commit f23c4b3924 ("bpf: Start using the BPF dispatcher in BPF_TEST_RUN") the unit test has slowed down significantly. Digging deeper reveals that the concurrent tests are serialised in the kernel on the XDP dispatcher. This is a global resource that is protected by a mutex, on which we contend. Fix this by not calling into the XDP dispatcher if we only want to perform a single run of the BPF program. See: https://lore.kernel.org/bpf/CACAyw9_y4QumOW35qpgTbLsJ532uGq-kVW-VESJzGyiZkypnvw@mail.gmail.com/ Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210928093100.27124-1-lmb@cloudflare.com		2021-09-29 14:10:05 -07:00
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Makefile	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
test_run.c	bpf: Do not invoke the XDP dispatcher for PROG_RUN with single repeat	2021-09-29 14:10:05 -07:00