Hi, On 12/20/2023 10:54 PM, Daniel Borkmann wrote: > On 12/19/23 2:56 PM, Hou Tao wrote: >> From: Hou Tao <houtao1@xxxxxxxxxx> >> >> Hi, >> >> The motivation for the patch set comes from the performance profiling of >> bpf memory allocator benchmark (will post it soon). The initial purpose >> of the benchmark is used to test whether or not there is performance >> degradation when using c->unit_size instead of ksize() to select the >> target cache for free [1]. The benchmark uses bpf_kptr_xchg() to stash >> the allocated objects and fetches the stashed objects for free. Based on >> the fix proposed in [1], After inling bpf_kptr_xchg(), the performance >> for object free increase about ~4%. > > It would probably make more sense if you place this also in the actual > patch as motivation / use case on /why/ it's needed. Thanks for the suggestion. Will added it in the inline patch. > >> Initially the inline is implemented in do_jit() for x86-64 directly, but >> I think it will more portable to implement the inline in verifier. >> Please see individual patches for more details. And comments are always >> welcome. >> >> [1]: >> https://lore.kernel.org/bpf/20231216131052.27621-1-houtao@xxxxxxxxxxxxxxx >> >> Hou Tao (3): >> bpf: Support inlining bpf_kptr_xchg() helper >> bpf, x86: Don't generate lock prefix for BPF_XCHG >> bpf, x86: Inline bpf_kptr_xchg() on x86-64 >> >> arch/x86/net/bpf_jit_comp.c | 9 ++++++++- >> include/linux/filter.h | 1 + >> kernel/bpf/core.c | 10 ++++++++++ >> kernel/bpf/verifier.c | 17 +++++++++++++++++ >> 4 files changed, 36 insertions(+), 1 deletion(-) >> > > nit: Needs a rebase. > . Will do.
