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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /tools/bpf/runqslower
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/bpf/runqslower')
-rw-r--r--tools/bpf/runqslower/.gitignore2
-rw-r--r--tools/bpf/runqslower/Makefile90
-rw-r--r--tools/bpf/runqslower/runqslower.bpf.c107
-rw-r--r--tools/bpf/runqslower/runqslower.c171
-rw-r--r--tools/bpf/runqslower/runqslower.h13
5 files changed, 383 insertions, 0 deletions
diff --git a/tools/bpf/runqslower/.gitignore b/tools/bpf/runqslower/.gitignore
new file mode 100644
index 000000000..ffdb70230
--- /dev/null
+++ b/tools/bpf/runqslower/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+/.output
diff --git a/tools/bpf/runqslower/Makefile b/tools/bpf/runqslower/Makefile
new file mode 100644
index 000000000..8b3d87b82
--- /dev/null
+++ b/tools/bpf/runqslower/Makefile
@@ -0,0 +1,90 @@
+# SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+include ../../scripts/Makefile.include
+
+OUTPUT ?= $(abspath .output)/
+
+BPFTOOL_OUTPUT := $(OUTPUT)bpftool/
+DEFAULT_BPFTOOL := $(BPFTOOL_OUTPUT)bootstrap/bpftool
+BPFTOOL ?= $(DEFAULT_BPFTOOL)
+LIBBPF_SRC := $(abspath ../../lib/bpf)
+BPFOBJ_OUTPUT := $(OUTPUT)libbpf/
+BPFOBJ := $(BPFOBJ_OUTPUT)libbpf.a
+BPF_DESTDIR := $(BPFOBJ_OUTPUT)
+BPF_INCLUDE := $(BPF_DESTDIR)/include
+INCLUDES := -I$(OUTPUT) -I$(BPF_INCLUDE) -I$(abspath ../../include/uapi)
+CFLAGS := -g -Wall $(CLANG_CROSS_FLAGS)
+
+# Try to detect best kernel BTF source
+KERNEL_REL := $(shell uname -r)
+VMLINUX_BTF_PATHS := $(if $(O),$(O)/vmlinux) \
+ $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux) \
+ ../../../vmlinux /sys/kernel/btf/vmlinux \
+ /boot/vmlinux-$(KERNEL_REL)
+VMLINUX_BTF_PATH := $(or $(VMLINUX_BTF),$(firstword \
+ $(wildcard $(VMLINUX_BTF_PATHS))))
+
+ifeq ($(V),1)
+Q =
+else
+Q = @
+MAKEFLAGS += --no-print-directory
+submake_extras := feature_display=0
+endif
+
+.DELETE_ON_ERROR:
+
+.PHONY: all clean runqslower libbpf_hdrs
+all: runqslower
+
+runqslower: $(OUTPUT)/runqslower
+
+clean:
+ $(call QUIET_CLEAN, runqslower)
+ $(Q)$(RM) -r $(BPFOBJ_OUTPUT) $(BPFTOOL_OUTPUT)
+ $(Q)$(RM) $(OUTPUT)*.o $(OUTPUT)*.d
+ $(Q)$(RM) $(OUTPUT)*.skel.h $(OUTPUT)vmlinux.h
+ $(Q)$(RM) $(OUTPUT)runqslower
+ $(Q)$(RM) -r .output
+
+libbpf_hdrs: $(BPFOBJ)
+
+$(OUTPUT)/runqslower: $(OUTPUT)/runqslower.o $(BPFOBJ)
+ $(QUIET_LINK)$(CC) $(CFLAGS) $^ -lelf -lz -o $@
+
+$(OUTPUT)/runqslower.o: runqslower.h $(OUTPUT)/runqslower.skel.h \
+ $(OUTPUT)/runqslower.bpf.o | libbpf_hdrs
+
+$(OUTPUT)/runqslower.bpf.o: $(OUTPUT)/vmlinux.h runqslower.h | libbpf_hdrs
+
+$(OUTPUT)/%.skel.h: $(OUTPUT)/%.bpf.o | $(BPFTOOL)
+ $(QUIET_GEN)$(BPFTOOL) gen skeleton $< > $@
+
+$(OUTPUT)/%.bpf.o: %.bpf.c $(BPFOBJ) | $(OUTPUT)
+ $(QUIET_GEN)$(CLANG) -g -O2 -target bpf $(INCLUDES) \
+ -c $(filter %.c,$^) -o $@ && \
+ $(LLVM_STRIP) -g $@
+
+$(OUTPUT)/%.o: %.c | $(OUTPUT)
+ $(QUIET_CC)$(CC) $(CFLAGS) $(INCLUDES) -c $(filter %.c,$^) -o $@
+
+$(OUTPUT) $(BPFOBJ_OUTPUT) $(BPFTOOL_OUTPUT):
+ $(QUIET_MKDIR)mkdir -p $@
+
+$(OUTPUT)/vmlinux.h: $(VMLINUX_BTF_PATH) | $(OUTPUT) $(BPFTOOL)
+ifeq ($(VMLINUX_H),)
+ $(Q)if [ ! -e "$(VMLINUX_BTF_PATH)" ] ; then \
+ echo "Couldn't find kernel BTF; set VMLINUX_BTF to" \
+ "specify its location." >&2; \
+ exit 1;\
+ fi
+ $(QUIET_GEN)$(BPFTOOL) btf dump file $(VMLINUX_BTF_PATH) format c > $@
+else
+ $(Q)cp "$(VMLINUX_H)" $@
+endif
+
+$(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(BPFOBJ_OUTPUT)
+ $(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC) OUTPUT=$(BPFOBJ_OUTPUT) \
+ DESTDIR=$(BPFOBJ_OUTPUT) prefix= $(abspath $@) install_headers
+
+$(DEFAULT_BPFTOOL): | $(BPFTOOL_OUTPUT)
+ $(Q)$(MAKE) $(submake_extras) -C ../bpftool OUTPUT=$(BPFTOOL_OUTPUT) bootstrap
diff --git a/tools/bpf/runqslower/runqslower.bpf.c b/tools/bpf/runqslower/runqslower.bpf.c
new file mode 100644
index 000000000..9a5c1f008
--- /dev/null
+++ b/tools/bpf/runqslower/runqslower.bpf.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2019 Facebook
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include "runqslower.h"
+
+#define TASK_RUNNING 0
+#define BPF_F_CURRENT_CPU 0xffffffffULL
+
+const volatile __u64 min_us = 0;
+const volatile pid_t targ_pid = 0;
+
+struct {
+ __uint(type, BPF_MAP_TYPE_TASK_STORAGE);
+ __uint(map_flags, BPF_F_NO_PREALLOC);
+ __type(key, int);
+ __type(value, u64);
+} start SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+ __uint(key_size, sizeof(u32));
+ __uint(value_size, sizeof(u32));
+} events SEC(".maps");
+
+/* record enqueue timestamp */
+__always_inline
+static int trace_enqueue(struct task_struct *t)
+{
+ u32 pid = t->pid;
+ u64 *ptr;
+
+ if (!pid || (targ_pid && targ_pid != pid))
+ return 0;
+
+ ptr = bpf_task_storage_get(&start, t, 0,
+ BPF_LOCAL_STORAGE_GET_F_CREATE);
+ if (!ptr)
+ return 0;
+
+ *ptr = bpf_ktime_get_ns();
+ return 0;
+}
+
+SEC("tp_btf/sched_wakeup")
+int handle__sched_wakeup(u64 *ctx)
+{
+ /* TP_PROTO(struct task_struct *p) */
+ struct task_struct *p = (void *)ctx[0];
+
+ return trace_enqueue(p);
+}
+
+SEC("tp_btf/sched_wakeup_new")
+int handle__sched_wakeup_new(u64 *ctx)
+{
+ /* TP_PROTO(struct task_struct *p) */
+ struct task_struct *p = (void *)ctx[0];
+
+ return trace_enqueue(p);
+}
+
+SEC("tp_btf/sched_switch")
+int handle__sched_switch(u64 *ctx)
+{
+ /* TP_PROTO(bool preempt, struct task_struct *prev,
+ * struct task_struct *next)
+ */
+ struct task_struct *prev = (struct task_struct *)ctx[1];
+ struct task_struct *next = (struct task_struct *)ctx[2];
+ struct runq_event event = {};
+ u64 *tsp, delta_us;
+ long state;
+ u32 pid;
+
+ /* ivcsw: treat like an enqueue event and store timestamp */
+ if (prev->__state == TASK_RUNNING)
+ trace_enqueue(prev);
+
+ pid = next->pid;
+
+ /* For pid mismatch, save a bpf_task_storage_get */
+ if (!pid || (targ_pid && targ_pid != pid))
+ return 0;
+
+ /* fetch timestamp and calculate delta */
+ tsp = bpf_task_storage_get(&start, next, 0, 0);
+ if (!tsp)
+ return 0; /* missed enqueue */
+
+ delta_us = (bpf_ktime_get_ns() - *tsp) / 1000;
+ if (min_us && delta_us <= min_us)
+ return 0;
+
+ event.pid = pid;
+ event.delta_us = delta_us;
+ bpf_get_current_comm(&event.task, sizeof(event.task));
+
+ /* output */
+ bpf_perf_event_output(ctx, &events, BPF_F_CURRENT_CPU,
+ &event, sizeof(event));
+
+ bpf_task_storage_delete(&start, next);
+ return 0;
+}
+
+char LICENSE[] SEC("license") = "GPL";
diff --git a/tools/bpf/runqslower/runqslower.c b/tools/bpf/runqslower/runqslower.c
new file mode 100644
index 000000000..83c5993a1
--- /dev/null
+++ b/tools/bpf/runqslower/runqslower.c
@@ -0,0 +1,171 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+// Copyright (c) 2019 Facebook
+#include <argp.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+#include "runqslower.h"
+#include "runqslower.skel.h"
+
+struct env {
+ pid_t pid;
+ __u64 min_us;
+ bool verbose;
+} env = {
+ .min_us = 10000,
+};
+
+const char *argp_program_version = "runqslower 0.1";
+const char *argp_program_bug_address = "<bpf@vger.kernel.org>";
+const char argp_program_doc[] =
+"runqslower Trace long process scheduling delays.\n"
+" For Linux, uses eBPF, BPF CO-RE, libbpf, BTF.\n"
+"\n"
+"This script traces high scheduling delays between tasks being\n"
+"ready to run and them running on CPU after that.\n"
+"\n"
+"USAGE: runqslower [-p PID] [min_us]\n"
+"\n"
+"EXAMPLES:\n"
+" runqslower # trace run queue latency higher than 10000 us (default)\n"
+" runqslower 1000 # trace run queue latency higher than 1000 us\n"
+" runqslower -p 123 # trace pid 123 only\n";
+
+static const struct argp_option opts[] = {
+ { "pid", 'p', "PID", 0, "Process PID to trace"},
+ { "verbose", 'v', NULL, 0, "Verbose debug output" },
+ {},
+};
+
+static error_t parse_arg(int key, char *arg, struct argp_state *state)
+{
+ static int pos_args;
+ int pid;
+ long long min_us;
+
+ switch (key) {
+ case 'v':
+ env.verbose = true;
+ break;
+ case 'p':
+ errno = 0;
+ pid = strtol(arg, NULL, 10);
+ if (errno || pid <= 0) {
+ fprintf(stderr, "Invalid PID: %s\n", arg);
+ argp_usage(state);
+ }
+ env.pid = pid;
+ break;
+ case ARGP_KEY_ARG:
+ if (pos_args++) {
+ fprintf(stderr,
+ "Unrecognized positional argument: %s\n", arg);
+ argp_usage(state);
+ }
+ errno = 0;
+ min_us = strtoll(arg, NULL, 10);
+ if (errno || min_us <= 0) {
+ fprintf(stderr, "Invalid delay (in us): %s\n", arg);
+ argp_usage(state);
+ }
+ env.min_us = min_us;
+ break;
+ default:
+ return ARGP_ERR_UNKNOWN;
+ }
+ return 0;
+}
+
+int libbpf_print_fn(enum libbpf_print_level level,
+ const char *format, va_list args)
+{
+ if (level == LIBBPF_DEBUG && !env.verbose)
+ return 0;
+ return vfprintf(stderr, format, args);
+}
+
+void handle_event(void *ctx, int cpu, void *data, __u32 data_sz)
+{
+ const struct runq_event *e = data;
+ struct tm *tm;
+ char ts[32];
+ time_t t;
+
+ time(&t);
+ tm = localtime(&t);
+ strftime(ts, sizeof(ts), "%H:%M:%S", tm);
+ printf("%-8s %-16s %-6d %14llu\n", ts, e->task, e->pid, e->delta_us);
+}
+
+void handle_lost_events(void *ctx, int cpu, __u64 lost_cnt)
+{
+ printf("Lost %llu events on CPU #%d!\n", lost_cnt, cpu);
+}
+
+int main(int argc, char **argv)
+{
+ static const struct argp argp = {
+ .options = opts,
+ .parser = parse_arg,
+ .doc = argp_program_doc,
+ };
+ struct perf_buffer *pb = NULL;
+ struct runqslower_bpf *obj;
+ int err;
+
+ err = argp_parse(&argp, argc, argv, 0, NULL, NULL);
+ if (err)
+ return err;
+
+ libbpf_set_print(libbpf_print_fn);
+
+ /* Use libbpf 1.0 API mode */
+ libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
+
+ obj = runqslower_bpf__open();
+ if (!obj) {
+ fprintf(stderr, "failed to open and/or load BPF object\n");
+ return 1;
+ }
+
+ /* initialize global data (filtering options) */
+ obj->rodata->targ_pid = env.pid;
+ obj->rodata->min_us = env.min_us;
+
+ err = runqslower_bpf__load(obj);
+ if (err) {
+ fprintf(stderr, "failed to load BPF object: %d\n", err);
+ goto cleanup;
+ }
+
+ err = runqslower_bpf__attach(obj);
+ if (err) {
+ fprintf(stderr, "failed to attach BPF programs\n");
+ goto cleanup;
+ }
+
+ printf("Tracing run queue latency higher than %llu us\n", env.min_us);
+ printf("%-8s %-16s %-6s %14s\n", "TIME", "COMM", "PID", "LAT(us)");
+
+ pb = perf_buffer__new(bpf_map__fd(obj->maps.events), 64,
+ handle_event, handle_lost_events, NULL, NULL);
+ err = libbpf_get_error(pb);
+ if (err) {
+ pb = NULL;
+ fprintf(stderr, "failed to open perf buffer: %d\n", err);
+ goto cleanup;
+ }
+
+ while ((err = perf_buffer__poll(pb, 100)) >= 0)
+ ;
+ printf("Error polling perf buffer: %d\n", err);
+
+cleanup:
+ perf_buffer__free(pb);
+ runqslower_bpf__destroy(obj);
+
+ return err != 0;
+}
diff --git a/tools/bpf/runqslower/runqslower.h b/tools/bpf/runqslower/runqslower.h
new file mode 100644
index 000000000..4f70f0720
--- /dev/null
+++ b/tools/bpf/runqslower/runqslower.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+#ifndef __RUNQSLOWER_H
+#define __RUNQSLOWER_H
+
+#define TASK_COMM_LEN 16
+
+struct runq_event {
+ char task[TASK_COMM_LEN];
+ __u64 delta_us;
+ pid_t pid;
+};
+
+#endif /* __RUNQSLOWER_H */