diff options
| author | Puranjay Mohan <puranjay@kernel.org> | 2024-05-02 15:18:52 +0000 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2024-05-12 16:54:34 -0700 |
| commit | 2ddec2c80b4402c293c7e6e0881cecaaf77e8cec (patch) | |
| tree | 89aee6a00fc8312f43c2fae605a8e0a4c9062721 /include/linux | |
| parent | 19c56d4e5be102cd118162b9f72d9c6d353e76fc (diff) | |
riscv, bpf: inline bpf_get_smp_processor_id()
Inline the calls to bpf_get_smp_processor_id() in the riscv bpf jit.
RISCV saves the pointer to the CPU's task_struct in the TP (thread
pointer) register. This makes it trivial to get the CPU's processor id.
As thread_info is the first member of task_struct, we can read the
processor id from TP + offsetof(struct thread_info, cpu).
RISCV64 JIT output for `call bpf_get_smp_processor_id`
======================================================
Before After
-------- -------
auipc t1,0x848c ld a5,32(tp)
jalr 604(t1)
mv a5,a0
Benchmark using [1] on Qemu.
./benchs/run_bench_trigger.sh glob-arr-inc arr-inc hash-inc
+---------------+------------------+------------------+--------------+
| Name | Before | After | % change |
|---------------+------------------+------------------+--------------|
| glob-arr-inc | 1.077 ± 0.006M/s | 1.336 ± 0.010M/s | + 24.04% |
| arr-inc | 1.078 ± 0.002M/s | 1.332 ± 0.015M/s | + 23.56% |
| hash-inc | 0.494 ± 0.004M/s | 0.653 ± 0.001M/s | + 32.18% |
+---------------+------------------+------------------+--------------+
NOTE: This benchmark includes changes from this patch and the previous
patch that implemented the per-cpu insn.
[1] https://github.com/anakryiko/linux/commit/8dec900975ef
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Björn Töpel <bjorn@kernel.org>
Link: https://lore.kernel.org/r/20240502151854.9810-3-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/filter.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/filter.h b/include/linux/filter.h index 7a27f19bf44d..3e19bb62ed1a 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -993,6 +993,7 @@ u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog); void bpf_jit_compile(struct bpf_prog *prog); bool bpf_jit_needs_zext(void); +bool bpf_jit_inlines_helper_call(s32 imm); bool bpf_jit_supports_subprog_tailcalls(void); bool bpf_jit_supports_percpu_insn(void); bool bpf_jit_supports_kfunc_call(void); |