kernel/linux.git/samples/bpf/map_perf_test_user.c, branch v4.18.17

samples: bpf: include bpf/bpf.h instead of local libbpf.h

2018-05-15T05:52:10+00:00

There are two files in the tree called libbpf.h which is becoming problematic. Most samples don't actually need the local libbpf.h they simply include it to get to bpf/bpf.h. Include bpf/bpf.h directly instead. Signed-off-by: Jakub Kicinski Acked-by: Jesper Dangaard Brouer Signed-off-by: Alexei Starovoitov

bpf: libbpf: Provide basic API support to specify BPF obj name

2017-09-29T05:17:05+00:00

This patch extends the libbpf to provide API support to allow specifying BPF object name. In tools/lib/bpf/libbpf, the C symbol of the function and the map is used. Regarding section name, all maps are under the same section named "maps". Hence, section name is not a good choice for map's name. To be consistent with map, bpf_prog also follows and uses its function symbol as the prog's name. This patch adds logic to collect function's symbols in libbpf. There is existing codes to collect the map's symbols and no change is needed. The bpf_load_program_name() and bpf_map_create_name() are added to take the name argument. For the other bpf_map_create_xxx() variants, a name argument is directly added to them. In samples/bpf, bpf_load.c in particular, the symbol is also used as the map's name and the map symbols has already been collected in the existing code. For bpf_prog, bpf_load.c does not collect the function symbol name. We can consider to collect them later if there is a need to continue supporting the bpf_load.c. Signed-off-by: Martin KaFai Lau Acked-by: Alexei Starovoitov Acked-by: Daniel Borkmann Signed-off-by: David S. Miller

samples/bpf: Use getppid instead of getpgrp for array map stress

2017-09-21T18:59:16+00:00

When cross-compiling the bpf sample map_perf_test for aarch64, I find that __NR_getpgrp is undefined. This causes build errors. This syscall is deprecated and requires defining __ARCH_WANT_SYSCALL_DEPRECATED. To avoid having to define that, just use a different syscall (getppid) for the array map stress test. Acked-by: Alexei Starovoitov Signed-off-by: Joel Fernandes Acked-by: Daniel Borkmann Signed-off-by: David S. Miller

bpf: Add lru_hash_lookup performance test

2017-09-01T16:57:38+00:00

Create a new case to test the LRU lookup performance. At the beginning, the LRU map is fully loaded (i.e. the number of keys is equal to map->max_entries). The lookup is done through key 0 to num_map_entries and then repeats from 0 again. This patch also creates an anonymous struct to properly name the test params in stress_lru_hmap_alloc() in map_perf_test_kern.c. Signed-off-by: Martin KaFai Lau Acked-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller

bpf: Allow numa selection in INNER_LRU_HASH_PREALLOC test of map_perf_test

2017-08-20T04:35:43+00:00

This patch makes the needed changes to allow each process of the INNER_LRU_HASH_PREALLOC test to provide its numa node id when creating the lru map. Signed-off-by: Martin KaFai Lau Acked-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller

samples/bpf: load_bpf.c make callback fixup more flexible

2017-05-03T13:30:24+00:00

Do this change before others start to use this callback. Change map_perf_test_user.c which seems to be the only user. This patch extends capabilities of commit 9fd63d05f3e8 ("bpf: Allow bpf sample programs (*_user.c) to change bpf_map_def"). Give fixup callback access to struct bpf_map_data, instead of only stuct bpf_map_def. This add flexibility to allow userspace to reassign the map file descriptor. This is very useful when wanting to share maps between several bpf programs. Signed-off-by: Jesper Dangaard Brouer Signed-off-by: David S. Miller

bpf: lru: Add map-in-map LRU example

2017-04-17T17:55:52+00:00

This patch adds a map-in-map LRU example. If we know only a subset of cores will use the LRU, we can allocate a common LRU list per targeting core and store it into an array-of-hashs. It allows using the common LRU map with map-update performance comparable to the BPF_F_NO_COMMON_LRU map but without wasting memory on the unused cores that we know they will never access the LRU map. BPF_F_NO_COMMON_LRU: > map_perf_test 32 8 10000000 10000000 | awk '{sum += $3}END{print sum}' 9234314 (9.23M/s) map-in-map LRU: > map_perf_test 512 8 1260000 80000000 | awk '{sum += $3}END{print sum}' 9962743 (9.96M/s) Notes that the max_entries for the map-in-map LRU test is 1260000 which is the max_entries for each inner LRU map. 8 processes have been started, so 8 * 1260000 = 10080000 (~10M) which is close to what is used in the BPF_F_NO_COMMON_LRU test. Signed-off-by: Martin KaFai Lau Signed-off-by: David S. Miller

bpf: Allow bpf sample programs (*_user.c) to change bpf_map_def

2017-04-17T17:55:52+00:00

The current bpf_map_def is statically defined during compile time. This patch allows the *_user.c program to change it during runtime. It is done by adding load_bpf_file_fixup_map() which takes a callback. The callback will be called before creating each map so that it has a chance to modify the bpf_map_def. The current usecase is to change max_entries in map_perf_test. It is interesting to test with a much bigger map size in some cases (e.g. the following patch on bpf_lru_map.c). However, it is hard to find one size to fit all testing environment. Hence, it is handy to take the max_entries as a cmdline arg and then configure the bpf_map_def during runtime. This patch adds two cmdline args. One is to configure the map's max_entries. Another is to configure the max_cnt which controls how many times a syscall is called. Signed-off-by: Martin KaFai Lau Acked-by: Alexei Starovoitov Acked-by: Daniel Borkmann Signed-off-by: David S. Miller

bpf: lru: Refactor LRU map tests in map_perf_test

2017-04-17T17:55:52+00:00

One more LRU test will be added later in this patch series. In this patch, we first move all existing LRU map tests into a single syscall (connect) first so that the future new LRU test can be added without hunting another syscall. One of the map name is also changed from percpu_lru_hash_map to nocommon_lru_hash_map to avoid the confusion with percpu_hash_map. Signed-off-by: Martin KaFai Lau Acked-by: Alexei Starovoitov Acked-by: Daniel Borkmann Signed-off-by: David S. Miller

samples/bpf: add map_lookup microbenchmark

2017-03-17T03:44:12+00:00

$ map_perf_test 128 speed of HASH bpf_map_lookup_elem() in lookups per second w/o JIT w/JIT before 46M 58M after 42M 74M perf report before: 54.23% map_perf_test [kernel.kallsyms] [k] __htab_map_lookup_elem 14.24% map_perf_test [kernel.kallsyms] [k] lookup_elem_raw 8.84% map_perf_test [kernel.kallsyms] [k] htab_map_lookup_elem 5.93% map_perf_test [kernel.kallsyms] [k] bpf_map_lookup_elem 2.30% map_perf_test [kernel.kallsyms] [k] bpf_prog_da4fc6a3f41761a2 1.49% map_perf_test [kernel.kallsyms] [k] kprobe_ftrace_handler after: 60.03% map_perf_test [kernel.kallsyms] [k] __htab_map_lookup_elem 18.07% map_perf_test [kernel.kallsyms] [k] lookup_elem_raw 2.91% map_perf_test [kernel.kallsyms] [k] bpf_prog_da4fc6a3f41761a2 1.94% map_perf_test [kernel.kallsyms] [k] _einittext 1.90% map_perf_test [kernel.kallsyms] [k] __audit_syscall_exit 1.72% map_perf_test [kernel.kallsyms] [k] kprobe_ftrace_handler Notice that bpf_map_lookup_elem() and htab_map_lookup_elem() are trivial functions, yet they take sizeable amount of cpu time. htab_map_gen_lookup() removes bpf_map_lookup_elem() and converts htab_map_lookup_elem() into three BPF insns which causing cpu time for bpf_prog_da4fc6a3f41761a2() slightly increase. $ map_perf_test 256 speed of ARRAY bpf_map_lookup_elem() in lookups per second w/o JIT w/JIT before 97M 174M after 64M 280M before: 37.33% map_perf_test [kernel.kallsyms] [k] array_map_lookup_elem 13.95% map_perf_test [kernel.kallsyms] [k] bpf_map_lookup_elem 6.54% map_perf_test [kernel.kallsyms] [k] bpf_prog_da4fc6a3f41761a2 4.57% map_perf_test [kernel.kallsyms] [k] kprobe_ftrace_handler after: 32.86% map_perf_test [kernel.kallsyms] [k] bpf_prog_da4fc6a3f41761a2 6.54% map_perf_test [kernel.kallsyms] [k] kprobe_ftrace_handler array_map_gen_lookup() removes calls to array_map_lookup_elem() and bpf_map_lookup_elem() and replaces them with 7 bpf insns. The performance without JIT is slower, since executing extra insns in the interpreter is slower than running native C code, but with JIT the performance gains are obvious, since native C->x86 code is replaced with fewer bpf->x86 instructions. Signed-off-by: Alexei Starovoitov Acked-by: Daniel Borkmann Signed-off-by: David S. Miller