From: Daniel Borkmann Date: Fri, 28 Aug 2020 19:20:33 +0000 (+0200) Subject: Merge branch 'bpf-sleepable' X-Git-Tag: v5.10-rc1~107^2~394^2~21 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=10496f261ed30592c6a7f8315f6b5ec055db624a;p=thirdparty%2Flinux.git Merge branch 'bpf-sleepable' Alexei Starovoitov says: ==================== v2->v3: - switched to minimal allowlist approach. Essentially that means that syscall entry, few btrfs allow_error_inject functions, should_fail_bio(), and two LSM hooks: file_mprotect and bprm_committed_creds are the only hooks that allow attaching of sleepable BPF programs. When comprehensive analysis of LSM hooks will be done this allowlist will be extended. - added patch 1 that fixes prototypes of two mm functions to reliably work with error injection. It's also necessary for resolve_btfids tool to recognize these two funcs, but that's secondary. v1->v2: - split fmod_ret fix into separate patch - added denylist v1: This patch set introduces the minimal viable support for sleepable bpf programs. In this patch only fentry/fexit/fmod_ret and lsm progs can be sleepable. Only array and pre-allocated hash and lru maps allowed. Here is 'perf report' difference of sleepable vs non-sleepable: 3.86% bench [k] __srcu_read_unlock 3.22% bench [k] __srcu_read_lock 0.92% bench [k] bpf_prog_740d4210cdcd99a3_bench_trigger_fentry_sleep 0.50% bench [k] bpf_trampoline_10297 0.26% bench [k] __bpf_prog_exit_sleepable 0.21% bench [k] __bpf_prog_enter_sleepable vs 0.88% bench [k] bpf_prog_740d4210cdcd99a3_bench_trigger_fentry 0.84% bench [k] bpf_trampoline_10297 0.13% bench [k] __bpf_prog_enter 0.12% bench [k] __bpf_prog_exit vs 0.79% bench [k] bpf_prog_740d4210cdcd99a3_bench_trigger_fentry_sleep 0.72% bench [k] bpf_trampoline_10381 0.31% bench [k] __bpf_prog_exit_sleepable 0.29% bench [k] __bpf_prog_enter_sleepable Sleepable vs non-sleepable program invocation overhead is only marginally higher due to rcu_trace. srcu approach is much slower. ==================== Signed-off-by: Daniel Borkmann --- 10496f261ed30592c6a7f8315f6b5ec055db624a