perf ftrace: Add -b/--use-bpf option for latency subcommand
The -b/--use-bpf option is to use BPF to get latency info of kernel
functions. It'd have better performance impact and I observed that
latency of same function is smaller than before when using BPF.
Committer testing:
# strace -e bpf perf ftrace latency -b -T __handle_mm_fault -a sleep 1
bpf(BPF_PROG_LOAD, {prog_type=BPF_PROG_TYPE_SOCKET_FILTER, insn_cnt=2, insns=0x7fff51914e00, license="GPL", log_level=0, log_size=0, log_buf=NULL, kern_version=KERNEL_VERSION(0, 0, 0), prog_flags=0, prog_name="", prog_ifindex=0, expected_attach_type=BPF_CGROUP_INET_INGRESS, prog_btf_fd=0, func_info_rec_size=0, func_info=NULL, func_info_cnt=0, line_info_rec_size=0, line_info=NULL, line_info_cnt=0, attach_btf_id=0, attach_prog_fd=0}, 128) = 3
bpf(BPF_BTF_LOAD, {btf="\237\353\1\0\30\0\0\0\0\0\0\0\20\0\0\0\20\0\0\0\5\0\0\0\1\0\0\0\0\0\0\1"..., btf_log_buf=NULL, btf_size=45, btf_log_size=0, btf_log_level=0}, 128) = 3
bpf(BPF_BTF_LOAD, {btf="\237\353\1\0\30\0\0\0\0\0\0\0000\0\0\0000\0\0\0\t\0\0\0\1\0\0\0\0\0\0\1"..., btf_log_buf=NULL, btf_size=81, btf_log_size=0, btf_log_level=0}, 128) = 3
bpf(BPF_BTF_LOAD, {btf="\237\353\1\0\30\0\0\0\0\0\0\08\0\0\08\0\0\0\t\0\0\0\0\0\0\0\0\0\0\1"..., btf_log_buf=NULL, btf_size=89, btf_log_size=0, btf_log_level=0}, 128) = 3
bpf(BPF_BTF_LOAD, {btf="\237\353\1\0\30\0\0\0\0\0\0\0\f\0\0\0\f\0\0\0\7\0\0\0\1\0\0\0\0\0\0\20"..., btf_log_buf=NULL, btf_size=43, btf_log_size=0, btf_log_level=0}, 128) = 3
bpf(BPF_BTF_LOAD, {btf="\237\353\1\0\30\0\0\0\0\0\0\0000\0\0\0000\0\0\0\t\0\0\0\1\0\0\0\0\0\0\1"..., btf_log_buf=NULL, btf_size=81, btf_log_size=0, btf_log_level=0}, 128) = 3
bpf(BPF_BTF_LOAD, {btf="\237\353\1\0\30\0\0\0\0\0\0\0000\0\0\0000\0\0\0\5\0\0\0\0\0\0\0\0\0\0\1"..., btf_log_buf=NULL, btf_size=77, btf_log_size=0, btf_log_level=0}, 128) = -1 EINVAL (Invalid argument)
bpf(BPF_BTF_LOAD, {btf="\237\353\1\0\30\0\0\0\0\0\0\0\350\2\0\0\350\2\0\0\353\2\0\0\0\0\0\0\0\0\0\2"..., btf_log_buf=NULL, btf_size=1515, btf_log_size=0, btf_log_level=0}, 128) = 3
bpf(BPF_MAP_CREATE, {map_type=BPF_MAP_TYPE_ARRAY, key_size=4, value_size=32, max_entries=1, map_flags=0, inner_map_fd=0, map_name="", map_ifindex=0, btf_fd=0, btf_key_type_id=0, btf_value_type_id=0, btf_vmlinux_value_type_id=0}, 128) = 4
bpf(BPF_PROG_LOAD, {prog_type=BPF_PROG_TYPE_SOCKET_FILTER, insn_cnt=5, insns=0x7fff51914c30, license="GPL", log_level=0, log_size=0, log_buf=NULL, kern_version=KERNEL_VERSION(0, 0, 0), prog_flags=0, prog_name="", prog_ifindex=0, expected_attach_type=BPF_CGROUP_INET_INGRESS, prog_btf_fd=0, func_info_rec_size=0, func_info=NULL, func_info_cnt=0, line_info_rec_size=0, line_info=NULL, line_info_cnt=0, attach_btf_id=0, attach_prog_fd=0}, 128) = 5
bpf(BPF_MAP_CREATE, {map_type=BPF_MAP_TYPE_ARRAY, key_size=4, value_size=4, max_entries=1, map_flags=BPF_F_MMAPABLE, inner_map_fd=0, map_name="", map_ifindex=0, btf_fd=0, btf_key_type_id=0, btf_value_type_id=0, btf_vmlinux_value_type_id=0}, 128) = 4
bpf(BPF_PROG_LOAD, {prog_type=BPF_PROG_TYPE_SOCKET_FILTER, insn_cnt=2, insns=0x7fff51914a80, license="GPL", log_level=0, log_size=0, log_buf=NULL, kern_version=KERNEL_VERSION(0, 0, 0), prog_flags=0, prog_name="test", prog_ifindex=0, expected_attach_type=BPF_CGROUP_INET_INGRESS, prog_btf_fd=0, func_info_rec_size=0, func_info=NULL, func_info_cnt=0, line_info_rec_size=0, line_info=NULL, line_info_cnt=0, attach_btf_id=0, attach_prog_fd=0}, 128) = 4
bpf(BPF_MAP_CREATE, {map_type=BPF_MAP_TYPE_HASH, key_size=8, value_size=8, max_entries=10000, map_flags=0, inner_map_fd=0, map_name="functime", map_ifindex=0, btf_fd=3, btf_key_type_id=0, btf_value_type_id=0, btf_vmlinux_value_type_id=0}, 128) = 4
bpf(BPF_MAP_CREATE, {map_type=BPF_MAP_TYPE_HASH, key_size=4, value_size=1, max_entries=1, map_flags=0, inner_map_fd=0, map_name="cpu_filter", map_ifindex=0, btf_fd=3, btf_key_type_id=0, btf_value_type_id=0, btf_vmlinux_value_type_id=0}, 128) = 5
bpf(BPF_MAP_CREATE, {map_type=BPF_MAP_TYPE_HASH, key_size=4, value_size=1, max_entries=1, map_flags=0, inner_map_fd=0, map_name="task_filter", map_ifindex=0, btf_fd=3, btf_key_type_id=0, btf_value_type_id=0, btf_vmlinux_value_type_id=0}, 128) = 7
bpf(BPF_MAP_CREATE, {map_type=BPF_MAP_TYPE_PERCPU_ARRAY, key_size=4, value_size=8, max_entries=22, map_flags=0, inner_map_fd=0, map_name="latency", map_ifindex=0, btf_fd=3, btf_key_type_id=0, btf_value_type_id=0, btf_vmlinux_value_type_id=0}, 128) = 8
bpf(BPF_MAP_CREATE, {map_type=BPF_MAP_TYPE_ARRAY, key_size=4, value_size=4, max_entries=1, map_flags=BPF_F_MMAPABLE, inner_map_fd=0, map_name="func_lat.bss", map_ifindex=0, btf_fd=3, btf_key_type_id=0, btf_value_type_id=30, btf_vmlinux_value_type_id=0}, 128) = 9
bpf(BPF_MAP_UPDATE_ELEM, {map_fd=9, key=0x7fff51914c40, value=0x7f6e99be2000, flags=BPF_ANY}, 128) = 0
bpf(BPF_PROG_LOAD, {prog_type=BPF_PROG_TYPE_KPROBE, insn_cnt=18, insns=0x11e4160, license="", log_level=0, log_size=0, log_buf=NULL, kern_version=KERNEL_VERSION(5, 14, 16), prog_flags=0, prog_name="func_begin", prog_ifindex=0, expected_attach_type=BPF_CGROUP_INET_INGRESS, prog_btf_fd=3, func_info_rec_size=8, func_info=0x11dfc50, func_info_cnt=1, line_info_rec_size=16, line_info=0x11e04c0, line_info_cnt=9, attach_btf_id=0, attach_prog_fd=0}, 128) = 10
bpf(BPF_PROG_LOAD, {prog_type=BPF_PROG_TYPE_KPROBE, insn_cnt=99, insns=0x11ded70, license="", log_level=0, log_size=0, log_buf=NULL, kern_version=KERNEL_VERSION(5, 14, 16), prog_flags=0, prog_name="func_end", prog_ifindex=0, expected_attach_type=BPF_CGROUP_INET_INGRESS, prog_btf_fd=3, func_info_rec_size=8, func_info=0x11dfc70, func_info_cnt=1, line_info_rec_size=16, line_info=0x11f6e10, line_info_cnt=20, attach_btf_id=0, attach_prog_fd=0}, 128) = 11
bpf(BPF_PROG_LOAD, {prog_type=BPF_PROG_TYPE_TRACEPOINT, insn_cnt=2, insns=0x7fff51914a80, license="GPL", log_level=0, log_size=0, log_buf=NULL, kern_version=KERNEL_VERSION(0, 0, 0), prog_flags=0, prog_name="", prog_ifindex=0, expected_attach_type=BPF_CGROUP_INET_INGRESS, prog_btf_fd=0, func_info_rec_size=0, func_info=NULL, func_info_cnt=0, line_info_rec_size=0, line_info=NULL, line_info_cnt=0, attach_btf_id=0, attach_prog_fd=0}, 128) = 13
bpf(BPF_LINK_CREATE, {link_create={prog_fd=13, target_fd=-1, attach_type=0x29 /* BPF_??? */, flags=0}}, 128) = -1 EINVAL (Invalid argument)
--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=1699992, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
# DURATION | COUNT | GRAPH |
0 - 1 us | 52 | ################### |
1 - 2 us | 36 | ############# |
2 - 4 us | 24 | ######### |
4 - 8 us | 7 | ## |
8 - 16 us | 1 | |
16 - 32 us | 0 | |
32 - 64 us | 0 | |
64 - 128 us | 0 | |
128 - 256 us | 0 | |
256 - 512 us | 0 | |
512 - 1024 us | 0 | |
1 - 2 ms | 0 | |
2 - 4 ms | 0 | |
4 - 8 ms | 0 | |
8 - 16 ms | 0 | |
16 - 32 ms | 0 | |
32 - 64 ms | 0 | |
64 - 128 ms | 0 | |
128 - 256 ms | 0 | |
256 - 512 ms | 0 | |
512 - 1024 ms | 0 | |
1 - ... s | 0 | |
+++ exited with 0 +++
#
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: Changbin Du <changbin.du@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20211215185154.360314-5-namhyung@kernel.org
[ Add missing util/cpumap.h include and removed unused 'fd' variable ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Namhyung Kim
Arnaldo Carvalho de Melo
Родитель
53be502822
Коммит
177f4eac7f
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@ -1041,7 +1041,7 @@ SKEL_OUT := $(abspath $(OUTPUT)util/bpf_skel)
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SKEL_TMP_OUT := $(abspath $(SKEL_OUT)/.tmp)
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SKELETONS := $(SKEL_OUT)/bpf_prog_profiler.skel.h
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SKELETONS += $(SKEL_OUT)/bperf_leader.skel.h $(SKEL_OUT)/bperf_follower.skel.h
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SKELETONS += $(SKEL_OUT)/bperf_cgroup.skel.h
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SKELETONS += $(SKEL_OUT)/bperf_cgroup.skel.h $(SKEL_OUT)/func_latency.skel.h
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$(SKEL_TMP_OUT) $(LIBBPF_OUTPUT):
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$(Q)$(MKDIR) -p $@
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@ -30,36 +30,12 @@
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#include "strfilter.h"
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#include "util/cap.h"
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#include "util/config.h"
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#include "util/ftrace.h"
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#include "util/units.h"
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#include "util/parse-sublevel-options.h"
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#define DEFAULT_TRACER "function_graph"
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struct perf_ftrace {
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struct evlist *evlist;
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struct target target;
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const char *tracer;
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struct list_head filters;
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struct list_head notrace;
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struct list_head graph_funcs;
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struct list_head nograph_funcs;
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int graph_depth;
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unsigned long percpu_buffer_size;
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bool inherit;
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int func_stack_trace;
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int func_irq_info;
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int graph_nosleep_time;
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int graph_noirqs;
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int graph_verbose;
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int graph_thresh;
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unsigned int initial_delay;
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};
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struct filter_entry {
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struct list_head list;
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char name[];
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};
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static volatile int workload_exec_errno;
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static bool done;
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@ -704,8 +680,6 @@ out:
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return (done && !workload_exec_errno) ? 0 : -1;
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}
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#define NUM_BUCKET 22 /* 20 + 2 (for outliers in both direction) */
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static void make_histogram(int buckets[], char *buf, size_t len, char *linebuf)
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{
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char *p, *q;
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@ -816,9 +790,87 @@ static void display_histogram(int buckets[])
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}
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static int __cmd_latency(struct perf_ftrace *ftrace)
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static int prepare_func_latency(struct perf_ftrace *ftrace)
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{
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char *trace_file;
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int fd;
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if (ftrace->target.use_bpf)
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return perf_ftrace__latency_prepare_bpf(ftrace);
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if (reset_tracing_files(ftrace) < 0) {
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pr_err("failed to reset ftrace\n");
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return -1;
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}
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/* reset ftrace buffer */
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if (write_tracing_file("trace", "0") < 0)
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return -1;
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if (set_tracing_options(ftrace) < 0)
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return -1;
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/* force to use the function_graph tracer to track duration */
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if (write_tracing_file("current_tracer", "function_graph") < 0) {
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pr_err("failed to set current_tracer to function_graph\n");
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return -1;
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}
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trace_file = get_tracing_file("trace_pipe");
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if (!trace_file) {
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pr_err("failed to open trace_pipe\n");
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return -1;
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}
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fd = open(trace_file, O_RDONLY);
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if (fd < 0)
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pr_err("failed to open trace_pipe\n");
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put_tracing_file(trace_file);
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return fd;
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}
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static int start_func_latency(struct perf_ftrace *ftrace)
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{
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if (ftrace->target.use_bpf)
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return perf_ftrace__latency_start_bpf(ftrace);
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if (write_tracing_file("tracing_on", "1") < 0) {
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pr_err("can't enable tracing\n");
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return -1;
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}
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return 0;
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}
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static int stop_func_latency(struct perf_ftrace *ftrace)
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{
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if (ftrace->target.use_bpf)
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return perf_ftrace__latency_stop_bpf(ftrace);
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write_tracing_file("tracing_on", "0");
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return 0;
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}
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static int read_func_latency(struct perf_ftrace *ftrace, int buckets[])
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{
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if (ftrace->target.use_bpf)
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return perf_ftrace__latency_read_bpf(ftrace, buckets);
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return 0;
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}
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static int cleanup_func_latency(struct perf_ftrace *ftrace)
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{
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if (ftrace->target.use_bpf)
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return perf_ftrace__latency_cleanup_bpf(ftrace);
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reset_tracing_files(ftrace);
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return 0;
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}
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static int __cmd_latency(struct perf_ftrace *ftrace)
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{
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int trace_fd;
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char buf[4096];
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char line[256];
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@ -839,46 +891,15 @@ static int __cmd_latency(struct perf_ftrace *ftrace)
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return -1;
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}
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if (reset_tracing_files(ftrace) < 0) {
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pr_err("failed to reset ftrace\n");
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trace_fd = prepare_func_latency(ftrace);
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if (trace_fd < 0)
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goto out;
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}
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/* reset ftrace buffer */
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if (write_tracing_file("trace", "0") < 0)
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goto out;
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if (set_tracing_options(ftrace) < 0)
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goto out_reset;
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/* force to use the function_graph tracer to track duration */
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if (write_tracing_file("current_tracer", "function_graph") < 0) {
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pr_err("failed to set current_tracer to function_graph\n");
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goto out_reset;
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}
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trace_file = get_tracing_file("trace_pipe");
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if (!trace_file) {
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pr_err("failed to open trace_pipe\n");
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goto out_reset;
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}
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trace_fd = open(trace_file, O_RDONLY);
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put_tracing_file(trace_file);
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if (trace_fd < 0) {
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pr_err("failed to open trace_pipe\n");
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goto out_reset;
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}
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fcntl(trace_fd, F_SETFL, O_NONBLOCK);
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pollfd.fd = trace_fd;
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if (write_tracing_file("tracing_on", "1") < 0) {
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pr_err("can't enable tracing\n");
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goto out_close_fd;
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}
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if (start_func_latency(ftrace) < 0)
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goto out;
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|
||||
evlist__start_workload(ftrace->evlist);
|
||||
|
||||
|
|
@ -896,29 +917,30 @@ static int __cmd_latency(struct perf_ftrace *ftrace)
|
|||
}
|
||||
}
|
||||
|
||||
write_tracing_file("tracing_on", "0");
|
||||
stop_func_latency(ftrace);
|
||||
|
||||
if (workload_exec_errno) {
|
||||
const char *emsg = str_error_r(workload_exec_errno, buf, sizeof(buf));
|
||||
pr_err("workload failed: %s\n", emsg);
|
||||
goto out_close_fd;
|
||||
goto out;
|
||||
}
|
||||
|
||||
/* read remaining buffer contents */
|
||||
while (true) {
|
||||
while (!ftrace->target.use_bpf) {
|
||||
int n = read(trace_fd, buf, sizeof(buf) - 1);
|
||||
if (n <= 0)
|
||||
break;
|
||||
make_histogram(buckets, buf, n, line);
|
||||
}
|
||||
|
||||
read_func_latency(ftrace, buckets);
|
||||
|
||||
display_histogram(buckets);
|
||||
|
||||
out_close_fd:
|
||||
close(trace_fd);
|
||||
out_reset:
|
||||
reset_tracing_files(ftrace);
|
||||
out:
|
||||
close(trace_fd);
|
||||
cleanup_func_latency(ftrace);
|
||||
|
||||
return (done && !workload_exec_errno) ? 0 : -1;
|
||||
}
|
||||
|
||||
|
|
@ -1144,6 +1166,10 @@ int cmd_ftrace(int argc, const char **argv)
|
|||
const struct option latency_options[] = {
|
||||
OPT_CALLBACK('T', "trace-funcs", &ftrace.filters, "func",
|
||||
"Show latency of given function", parse_filter_func),
|
||||
#ifdef HAVE_BPF_SKEL
|
||||
OPT_BOOLEAN('b', "use-bpf", &ftrace.target.use_bpf,
|
||||
"Use BPF to measure function latency"),
|
||||
#endif
|
||||
OPT_PARENT(common_options),
|
||||
};
|
||||
const struct option *options = ftrace_options;
|
||||
|
|
|
|||
|
|
@ -144,6 +144,7 @@ perf-$(CONFIG_LIBBPF) += bpf-loader.o
|
|||
perf-$(CONFIG_LIBBPF) += bpf_map.o
|
||||
perf-$(CONFIG_PERF_BPF_SKEL) += bpf_counter.o
|
||||
perf-$(CONFIG_PERF_BPF_SKEL) += bpf_counter_cgroup.o
|
||||
perf-$(CONFIG_PERF_BPF_SKEL) += bpf_ftrace.o
|
||||
perf-$(CONFIG_BPF_PROLOGUE) += bpf-prologue.o
|
||||
perf-$(CONFIG_LIBELF) += symbol-elf.o
|
||||
perf-$(CONFIG_LIBELF) += probe-file.o
|
||||
|
|
|
|||
|
|
@ -0,0 +1,112 @@
|
|||
#include <stdio.h>
|
||||
#include <fcntl.h>
|
||||
#include <stdint.h>
|
||||
#include <stdlib.h>
|
||||
|
||||
#include <linux/err.h>
|
||||
|
||||
#include "util/ftrace.h"
|
||||
#include "util/cpumap.h"
|
||||
#include "util/debug.h"
|
||||
#include "util/bpf_counter.h"
|
||||
|
||||
#include "util/bpf_skel/func_latency.skel.h"
|
||||
|
||||
static struct func_latency_bpf *skel;
|
||||
|
||||
int perf_ftrace__latency_prepare_bpf(struct perf_ftrace *ftrace)
|
||||
{
|
||||
int err;
|
||||
struct filter_entry *func;
|
||||
|
||||
if (!list_is_singular(&ftrace->filters)) {
|
||||
pr_err("ERROR: %s target function(s).\n",
|
||||
list_empty(&ftrace->filters) ? "No" : "Too many");
|
||||
return -1;
|
||||
}
|
||||
|
||||
func = list_first_entry(&ftrace->filters, struct filter_entry, list);
|
||||
|
||||
skel = func_latency_bpf__open();
|
||||
if (!skel) {
|
||||
pr_err("Failed to open func latency skeleton\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
set_max_rlimit();
|
||||
|
||||
err = func_latency_bpf__load(skel);
|
||||
if (err) {
|
||||
pr_err("Failed to load func latency skeleton\n");
|
||||
goto out;
|
||||
}
|
||||
|
||||
skel->links.func_begin = bpf_program__attach_kprobe(skel->progs.func_begin,
|
||||
false, func->name);
|
||||
if (IS_ERR(skel->links.func_begin)) {
|
||||
pr_err("Failed to attach fentry program\n");
|
||||
err = PTR_ERR(skel->links.func_begin);
|
||||
goto out;
|
||||
}
|
||||
|
||||
skel->links.func_end = bpf_program__attach_kprobe(skel->progs.func_end,
|
||||
true, func->name);
|
||||
if (IS_ERR(skel->links.func_end)) {
|
||||
pr_err("Failed to attach fexit program\n");
|
||||
err = PTR_ERR(skel->links.func_end);
|
||||
goto out;
|
||||
}
|
||||
|
||||
/* XXX: we don't actually use this fd - just for poll() */
|
||||
return open("/dev/null", O_RDONLY);
|
||||
|
||||
out:
|
||||
return err;
|
||||
}
|
||||
|
||||
int perf_ftrace__latency_start_bpf(struct perf_ftrace *ftrace __maybe_unused)
|
||||
{
|
||||
skel->bss->enabled = 1;
|
||||
return 0;
|
||||
}
|
||||
|
||||
int perf_ftrace__latency_stop_bpf(struct perf_ftrace *ftrace __maybe_unused)
|
||||
{
|
||||
skel->bss->enabled = 0;
|
||||
return 0;
|
||||
}
|
||||
|
||||
int perf_ftrace__latency_read_bpf(struct perf_ftrace *ftrace __maybe_unused,
|
||||
int buckets[])
|
||||
{
|
||||
int i, fd, err;
|
||||
u32 idx;
|
||||
u64 *hist;
|
||||
int ncpus = cpu__max_cpu();
|
||||
|
||||
fd = bpf_map__fd(skel->maps.latency);
|
||||
|
||||
hist = calloc(ncpus, sizeof(*hist));
|
||||
if (hist == NULL)
|
||||
return -ENOMEM;
|
||||
|
||||
for (idx = 0; idx < NUM_BUCKET; idx++) {
|
||||
err = bpf_map_lookup_elem(fd, &idx, hist);
|
||||
if (err) {
|
||||
buckets[idx] = 0;
|
||||
continue;
|
||||
}
|
||||
|
||||
for (i = 0; i < ncpus; i++)
|
||||
buckets[idx] += hist[i];
|
||||
}
|
||||
|
||||
free(hist);
|
||||
return 0;
|
||||
}
|
||||
|
||||
int perf_ftrace__latency_cleanup_bpf(struct perf_ftrace *ftrace __maybe_unused)
|
||||
{
|
||||
func_latency_bpf__destroy(skel);
|
||||
return 0;
|
||||
}
|
||||
|
|
@ -0,0 +1,93 @@
|
|||
// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
|
||||
// Copyright (c) 2021 Google
|
||||
#include "vmlinux.h"
|
||||
#include <bpf/bpf_helpers.h>
|
||||
#include <bpf/bpf_tracing.h>
|
||||
|
||||
// This should be in sync with "util/ftrace.h"
|
||||
#define NUM_BUCKET 22
|
||||
|
||||
struct {
|
||||
__uint(type, BPF_MAP_TYPE_HASH);
|
||||
__uint(key_size, sizeof(__u64));
|
||||
__uint(value_size, sizeof(__u64));
|
||||
__uint(max_entries, 10000);
|
||||
} functime SEC(".maps");
|
||||
|
||||
struct {
|
||||
__uint(type, BPF_MAP_TYPE_HASH);
|
||||
__uint(key_size, sizeof(__u32));
|
||||
__uint(value_size, sizeof(__u8));
|
||||
__uint(max_entries, 1);
|
||||
} cpu_filter SEC(".maps");
|
||||
|
||||
struct {
|
||||
__uint(type, BPF_MAP_TYPE_HASH);
|
||||
__uint(key_size, sizeof(__u32));
|
||||
__uint(value_size, sizeof(__u8));
|
||||
__uint(max_entries, 1);
|
||||
} task_filter SEC(".maps");
|
||||
|
||||
struct {
|
||||
__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
|
||||
__uint(key_size, sizeof(__u32));
|
||||
__uint(value_size, sizeof(__u64));
|
||||
__uint(max_entries, NUM_BUCKET);
|
||||
} latency SEC(".maps");
|
||||
|
||||
|
||||
int enabled = 0;
|
||||
|
||||
SEC("kprobe/func")
|
||||
int BPF_PROG(func_begin)
|
||||
{
|
||||
__u64 key, now;
|
||||
|
||||
if (!enabled)
|
||||
return 0;
|
||||
|
||||
key = bpf_get_current_pid_tgid();
|
||||
now = bpf_ktime_get_ns();
|
||||
|
||||
// overwrite timestamp for nested functions
|
||||
bpf_map_update_elem(&functime, &key, &now, BPF_ANY);
|
||||
return 0;
|
||||
}
|
||||
|
||||
SEC("kretprobe/func")
|
||||
int BPF_PROG(func_end)
|
||||
{
|
||||
__u64 tid;
|
||||
__u64 *start;
|
||||
|
||||
if (!enabled)
|
||||
return 0;
|
||||
|
||||
tid = bpf_get_current_pid_tgid();
|
||||
|
||||
start = bpf_map_lookup_elem(&functime, &tid);
|
||||
if (start) {
|
||||
__s64 delta = bpf_ktime_get_ns() - *start;
|
||||
__u32 key;
|
||||
__u64 *hist;
|
||||
|
||||
bpf_map_delete_elem(&functime, &tid);
|
||||
|
||||
if (delta < 0)
|
||||
return 0;
|
||||
|
||||
// calculate index using delta in usec
|
||||
for (key = 0; key < (NUM_BUCKET - 1); key++) {
|
||||
if (delta < ((1000UL) << key))
|
||||
break;
|
||||
}
|
||||
|
||||
hist = bpf_map_lookup_elem(&latency, &key);
|
||||
if (!hist)
|
||||
return 0;
|
||||
|
||||
*hist += 1;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
|
@ -0,0 +1,81 @@
|
|||
#ifndef __PERF_FTRACE_H__
|
||||
#define __PERF_FTRACE_H__
|
||||
|
||||
#include <linux/list.h>
|
||||
|
||||
#include "target.h"
|
||||
|
||||
struct evlist;
|
||||
|
||||
struct perf_ftrace {
|
||||
struct evlist *evlist;
|
||||
struct target target;
|
||||
const char *tracer;
|
||||
struct list_head filters;
|
||||
struct list_head notrace;
|
||||
struct list_head graph_funcs;
|
||||
struct list_head nograph_funcs;
|
||||
unsigned long percpu_buffer_size;
|
||||
bool inherit;
|
||||
int graph_depth;
|
||||
int func_stack_trace;
|
||||
int func_irq_info;
|
||||
int graph_nosleep_time;
|
||||
int graph_noirqs;
|
||||
int graph_verbose;
|
||||
int graph_thresh;
|
||||
unsigned int initial_delay;
|
||||
};
|
||||
|
||||
struct filter_entry {
|
||||
struct list_head list;
|
||||
char name[];
|
||||
};
|
||||
|
||||
#define NUM_BUCKET 22 /* 20 + 2 (for outliers in both direction) */
|
||||
|
||||
#ifdef HAVE_BPF_SKEL
|
||||
|
||||
int perf_ftrace__latency_prepare_bpf(struct perf_ftrace *ftrace);
|
||||
int perf_ftrace__latency_start_bpf(struct perf_ftrace *ftrace);
|
||||
int perf_ftrace__latency_stop_bpf(struct perf_ftrace *ftrace);
|
||||
int perf_ftrace__latency_read_bpf(struct perf_ftrace *ftrace,
|
||||
int buckets[]);
|
||||
int perf_ftrace__latency_cleanup_bpf(struct perf_ftrace *ftrace);
|
||||
|
||||
#else /* !HAVE_BPF_SKEL */
|
||||
|
||||
static inline int
|
||||
perf_ftrace__latency_prepare_bpf(struct perf_ftrace *ftrace __maybe_unused)
|
||||
{
|
||||
return -1;
|
||||
}
|
||||
|
||||
static inline int
|
||||
perf_ftrace__latency_start_bpf(struct perf_ftrace *ftrace __maybe_unused)
|
||||
{
|
||||
return -1;
|
||||
}
|
||||
|
||||
static inline int
|
||||
perf_ftrace__latency_stop_bpf(struct perf_ftrace *ftrace __maybe_unused)
|
||||
{
|
||||
return -1;
|
||||
}
|
||||
|
||||
static inline int
|
||||
perf_ftrace__latency_read_bpf(struct perf_ftrace *ftrace __maybe_unused,
|
||||
int buckets[] __maybe_unused)
|
||||
{
|
||||
return -1;
|
||||
}
|
||||
|
||||
static inline int
|
||||
perf_ftrace__latency_cleanup_bpf(struct perf_ftrace *ftrace __maybe_unused)
|
||||
{
|
||||
return -1;
|
||||
}
|
||||
|
||||
#endif /* HAVE_BPF_SKEL */
|
||||
|
||||
#endif /* __PERF_FTRACE_H__ */
|
||||
Загрузка…
Ссылка в новой задаче