Le 10/11/2022 à 19:43, Hari Bathini a écrit : > Most BPF programs are small, but they consume a page each. For systems > with busy traffic and many BPF programs, this may also add significant > pressure on instruction TLB. High iTLB pressure usually slows down the > whole system causing visible performance degradation for production > workloads. > > bpf_prog_pack, a customized allocator that packs multiple bpf programs > into preallocated memory chunks, was proposed [1] to address it. This > series extends this support on powerpc. > > Patches 1 & 2 add the arch specific functions needed to support this > feature. Patch 3 enables the support for powerpc. The last patch > ensures cleanup is handled racefully. > > Tested the changes successfully on a PowerVM. patch_instruction(), > needed for bpf_arch_text_copy(), is failing for ppc32. Debugging it. > Posting the patches in the meanwhile for feedback on these changes. I did a quick test on ppc32, I don't get such a problem, only something wrong in the dump print as traps intructions only are dumped, but tcpdump works as expected: [ 55.692998] bpf_jit_enable = 2 was set! NEVER use this in production, only for JIT debugging! [ 66.279259] device eth0 entered promiscuous mode [ 67.214756] Pass 1: shrink = 0, seen = 0x1f980000 [ 67.214880] Pass 2: shrink = 0, seen = 0x1f980000 [ 67.214966] flen=5 proglen=60 pass=3 image=be7a8038 from=tcpdump pid=459 [ 67.225261] JIT code: 00000000: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.233904] JIT code: 00000010: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.242579] JIT code: 00000020: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.249694] JIT code: 00000030: 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.259255] Pass 1: shrink = 0, seen = 0x3ff801fe [ 67.259421] Pass 2: shrink = 0, seen = 0x3ff801fe [ 67.259514] flen=40 proglen=504 pass=3 image=be7a80a0 from=tcpdump pid=459 [ 67.269467] JIT code: 00000000: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.278001] JIT code: 00000010: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.286519] JIT code: 00000020: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.295041] JIT code: 00000030: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.303596] JIT code: 00000040: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.312164] JIT code: 00000050: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.319231] JIT code: 00000060: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.328822] JIT code: 00000070: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.337382] JIT code: 00000080: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.345901] JIT code: 00000090: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.354423] JIT code: 000000a0: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.362941] JIT code: 000000b0: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.371462] JIT code: 000000c0: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.378526] JIT code: 000000d0: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.388120] JIT code: 000000e0: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.396680] JIT code: 000000f0: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.405199] JIT code: 00000100: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.413756] JIT code: 00000110: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.422324] JIT code: 00000120: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.429389] JIT code: 00000130: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.438982] JIT code: 00000140: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.447541] JIT code: 00000150: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.456059] JIT code: 00000160: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.464578] JIT code: 00000170: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.473201] JIT code: 00000180: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.481705] JIT code: 00000190: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.488770] JIT code: 000001a0: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.498359] JIT code: 000001b0: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.506921] JIT code: 000001c0: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.515439] JIT code: 000001d0: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.523998] JIT code: 000001e0: 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08 [ 67.532565] JIT code: 000001f0: 7f e0 00 08 7f e0 00 08 [ 82.620898] device eth0 left promiscuous mode > > [1] https://lore.kernel.org/bpf/20220204185742.271030-1-song@xxxxxxxxxx/ > > Hari Bathini (3): > powerpc/bpf: implement bpf_arch_text_copy > powerpc/bpf: implement bpf_arch_text_invalidate for bpf_prog_pack > powerpc/bpf: use bpf_jit_binary_pack_[alloc|finalize|free] > > arch/powerpc/net/bpf_jit.h | 18 +-- > arch/powerpc/net/bpf_jit_comp.c | 194 ++++++++++++++++++++++++------ > arch/powerpc/net/bpf_jit_comp32.c | 26 ++-- > arch/powerpc/net/bpf_jit_comp64.c | 32 ++--- > 4 files changed, 198 insertions(+), 72 deletions(-) >
