mirror of https://gitee.com/openkylin/linux.git
3 Commits
| Author | SHA1 | Message | Date |
|---|---|---|---|
Martin KaFai Lau
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12d8bb64e3 |
bpf: xdp: Add XDP example for head adjustment
The XDP prog checks if the incoming packet matches any VIP:PORT combination in the BPF hashmap. If it is, it will encapsulate the packet with a IPv4/v6 header as instructed by the value of the BPF hashmap and then XDP_TX it out. The VIP:PORT -> IP-Encap-Info can be specified by the cmd args of the user prog. Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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Daniel Borkmann
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e00c7b216f |
bpf: fix multiple issues in selftest suite and samples
1) The test_lru_map and test_lru_dist fails building on my machine since
the sys/resource.h header is not included.
2) test_verifier fails in one test case where we try to call an invalid
function, since the verifier log output changed wrt printing function
names.
3) Current selftest suite code relies on sysconf(_SC_NPROCESSORS_CONF) for
retrieving the number of possible CPUs. This is broken at least in our
scenario and really just doesn't work.
glibc tries a number of things for retrieving _SC_NPROCESSORS_CONF.
First it tries equivalent of /sys/devices/system/cpu/cpu[0-9]* | wc -l,
if that fails, depending on the config, it either tries to count CPUs
in /proc/cpuinfo, or returns the _SC_NPROCESSORS_ONLN value instead.
If /proc/cpuinfo has some issue, it returns just 1 worst case. This
oddity is nothing new [1], but semantics/behaviour seems to be settled.
_SC_NPROCESSORS_ONLN will parse /sys/devices/system/cpu/online, if
that fails it looks into /proc/stat for cpuX entries, and if also that
fails for some reason, /proc/cpuinfo is consulted (and returning 1 if
unlikely all breaks down).
While that might match num_possible_cpus() from the kernel in some
cases, it's really not guaranteed with CPU hotplugging, and can result
in a buffer overflow since the array in user space could have too few
number of slots, and on perpcu map lookup, the kernel will write beyond
that memory of the value buffer.
William Tu reported such mismatches:
[...] The fact that sysconf(_SC_NPROCESSORS_CONF) != num_possible_cpu()
happens when CPU hotadd is enabled. For example, in Fusion when
setting vcpu.hotadd = "TRUE" or in KVM, setting ./qemu-system-x86_64
-smp 2, maxcpus=4 ... the num_possible_cpu() will be 4 and sysconf()
will be 2 [2]. [...]
Documentation/cputopology.txt says /sys/devices/system/cpu/possible
outputs cpu_possible_mask. That is the same as in num_possible_cpus(),
so first step would be to fix the _SC_NPROCESSORS_CONF calls with our
own implementation. Later, we could add support to bpf(2) for passing
a mask via CPU_SET(3), for example, to just select a subset of CPUs.
BPF samples code needs this fix as well (at least so that people stop
copying this). Thus, define bpf_num_possible_cpus() once in selftests
and import it from there for the sample code to avoid duplicating it.
The remaining sysconf(_SC_NPROCESSORS_CONF) in samples are unrelated.
After all three issues are fixed, the test suite runs fine again:
# make run_tests | grep self
selftests: test_verifier [PASS]
selftests: test_maps [PASS]
selftests: test_lru_map [PASS]
selftests: test_kmod.sh [PASS]
[1] https://www.sourceware.org/ml/libc-alpha/2011-06/msg00079.html
[2] https://www.mail-archive.com/netdev@vger.kernel.org/msg121183.html
Fixes:
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Brenden Blanco
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86af8b4191 |
Add sample for adding simple drop program to link
Add a sample program that only drops packets at the BPF_PROG_TYPE_XDP_RX hook of a link. With the drop-only program, observed single core rate is ~20Mpps. Other tests were run, for instance without the dropcnt increment or without reading from the packet header, the packet rate was mostly unchanged. $ perf record -a samples/bpf/xdp1 $(</sys/class/net/eth0/ifindex) proto 17: 20403027 drops/s ./pktgen_sample03_burst_single_flow.sh -i $DEV -d $IP -m $MAC -t 4 Running... ctrl^C to stop Device: eth4@0 Result: OK: 11791017(c11788327+d2689) usec, 59622913 (60byte,0frags) 5056638pps 2427Mb/sec (2427186240bps) errors: 0 Device: eth4@1 Result: OK: 11791012(c11787906+d3106) usec, 60526944 (60byte,0frags) 5133311pps 2463Mb/sec (2463989280bps) errors: 0 Device: eth4@2 Result: OK: 11791019(c11788249+d2769) usec, 59868091 (60byte,0frags) 5077431pps 2437Mb/sec (2437166880bps) errors: 0 Device: eth4@3 Result: OK: 11795039(c11792403+d2636) usec, 59483181 (60byte,0frags) 5043067pps 2420Mb/sec (2420672160bps) errors: 0 perf report --no-children: 26.05% ksoftirqd/0 [mlx4_en] [k] mlx4_en_process_rx_cq 17.84% ksoftirqd/0 [mlx4_en] [k] mlx4_en_alloc_frags 5.52% ksoftirqd/0 [mlx4_en] [k] mlx4_en_free_frag 4.90% swapper [kernel.vmlinux] [k] poll_idle 4.14% ksoftirqd/0 [kernel.vmlinux] [k] get_page_from_freelist 2.78% ksoftirqd/0 [kernel.vmlinux] [k] __free_pages_ok 2.57% ksoftirqd/0 [kernel.vmlinux] [k] bpf_map_lookup_elem 2.51% swapper [mlx4_en] [k] mlx4_en_process_rx_cq 1.94% ksoftirqd/0 [kernel.vmlinux] [k] percpu_array_map_lookup_elem 1.45% swapper [mlx4_en] [k] mlx4_en_alloc_frags 1.35% ksoftirqd/0 [kernel.vmlinux] [k] free_one_page 1.33% swapper [kernel.vmlinux] [k] intel_idle 1.04% ksoftirqd/0 [mlx4_en] [k] 0x000000000001c5c5 0.96% ksoftirqd/0 [mlx4_en] [k] 0x000000000001c58d 0.93% ksoftirqd/0 [mlx4_en] [k] 0x000000000001c6ee 0.92% ksoftirqd/0 [mlx4_en] [k] 0x000000000001c6b9 0.89% ksoftirqd/0 [kernel.vmlinux] [k] __alloc_pages_nodemask 0.83% ksoftirqd/0 [mlx4_en] [k] 0x000000000001c686 0.83% ksoftirqd/0 [mlx4_en] [k] 0x000000000001c5d5 0.78% ksoftirqd/0 [mlx4_en] [k] mlx4_alloc_pages.isra.23 0.77% ksoftirqd/0 [mlx4_en] [k] 0x000000000001c5b4 0.77% ksoftirqd/0 [kernel.vmlinux] [k] net_rx_action machine specs: receiver - Intel E5-1630 v3 @ 3.70GHz sender - Intel E5645 @ 2.40GHz Mellanox ConnectX-3 @40G Signed-off-by: Brenden Blanco <bblanco@plumgrid.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> |