Add slabratetop libbpf-tools.

Total same as [slabratetop(8)](https://github.com/iovisor/bcc/blob/master/tools/slabratetop.py),
but add some options params:

```bash
$ sudo ./slabratetop -h
Usage: slabratetop [OPTION...]
Trace slab kmem cache alloc by process.

USAGE: slabratetop [-h] [-p PID] [interval] [count]

EXAMPLES:
    slabratetop            # slab rate top, refresh every 1s
    slabratetop -p 181     # only trace PID 181
    slabratetop -s count   # sort columns by count
    slabratetop -r 100     # print 100 rows
    slabratetop 5 10       # 5s summaries, 10 times

  -C, --noclear              Don't clear the screen
  -p, --pid=PID              Process ID to trace
  -r, --rows=ROWS            Maximum rows to print, default 20
  -s, --sort=SORT            Sort columns, default size [name, count, size]
  -v, --verbose              Verbose debug output
  -?, --help                 Give this help list
      --usage                Give a short usage message
  -V, --version              Print program version

Mandatory or optional arguments to long options are also mandatory or optional
for any corresponding short options.

Report bugs to https://github.com/iovisor/bcc/tree/master/libbpf-tools.
```

print like:

```bash
13:29:26 loadavg: 0.06 0.01 0.02 1/556 9961

CACHE                            ALLOCS      BYTES
names_cache                          86     374272
filp                                 43      27520
vm_area_struct                       87      22968
anon_vma                             32       8704
mm_struct                             3       5760
anon_vma_chain                       55       5280
cred_jar                             19       4864
dentry                               12       4704
page->ptl                            44       4576
UNIX                                  2       4224
proc_inode_cache                      3       3744
xfs_trans                            11       3256
skbuff_head_cache                     8       2560
seq_file                              8       2496
xfs_log_ticket                       10       2480
sighand_cache                         1       2368
signal_cache                          1       1792
xfs_btree_cur                         5       1440
sock_inode_cache                      1       1408
lsm_file_cache                       43       1376
```

libbpf-tools/.gitignore

@@ -38,6 +38,7 @@
 /runqlat
 /runqlen
 /runqslower
+/slabratetop
 /softirqs
 /solisten
 /statsnoop

libbpf-tools/Makefile

@@ -51,6 +51,7 @@ APPS = \
  runqlat \
  runqlen \
  runqslower \
+ slabratetop \
  softirqs \
  solisten \
  statsnoop \

libbpf-tools/slabratetop.bpf.c

@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+/* Copyright (c) 2022 Rong Tao */
+#include <vmlinux.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_core_read.h>
+#include <bpf/bpf_tracing.h>
+#include "slabratetop.h"
+
+#define MAX_ENTRIES 10240
+
+const volatile pid_t target_pid = 0;
+
+static struct slabrate_info slab_zero_value = {};
+
+struct {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __uint(max_entries, MAX_ENTRIES);
+ __type(key, char *);
+ __type(value, struct slabrate_info);
+} slab_entries SEC(".maps");
+
+static int probe_entry(struct kmem_cache *cachep)
+{
+ __u64 pid_tgid = bpf_get_current_pid_tgid();
+ __u32 pid = pid_tgid >> 32;
+ struct slabrate_info *valuep;
+ const char *name = BPF_CORE_READ(cachep, name);
+
+ if (target_pid && target_pid != pid)
+ return 0;
+
+ valuep = bpf_map_lookup_elem(&slab_entries, &name);
+ if (!valuep) {
+ bpf_map_update_elem(&slab_entries, &name, &slab_zero_value, BPF_ANY);
+ valuep = bpf_map_lookup_elem(&slab_entries, &name);
+ if (!valuep)
+ return 0;
+ bpf_probe_read_kernel(&valuep->name, sizeof(valuep->name), name);
+ }
+
+ valuep->count++;
+ valuep->size += BPF_CORE_READ(cachep, size);
+
+ return 0;
+}
+
+SEC("kprobe/kmem_cache_alloc")
+int BPF_KPROBE(kmem_cache_alloc, struct kmem_cache *cachep)
+{
+ return probe_entry(cachep);
+}
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";

libbpf-tools/slabratetop.c

@@ -0,0 +1,307 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+
+/*
+ * slabratetop Trace slab kmem_cache_alloc by process.
+ * Copyright (c) 2022 Rong Tao
+ *
+ * Based on slabratetop(8) from BCC by Brendan Gregg.
+ * 07-Jan-2022 Rong Tao Created this.
+ */
+#include <argp.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+#include "slabratetop.h"
+#include "slabratetop.skel.h"
+#include "trace_helpers.h"
+
+#define warn(...) fprintf(stderr, __VA_ARGS__)
+#define OUTPUT_ROWS_LIMIT 10240
+
+enum SORT_BY {
+ SORT_BY_CACHE_NAME,
+ SORT_BY_CACHE_COUNT,
+ SORT_BY_CACHE_SIZE,
+};
+
+static volatile sig_atomic_t exiting = 0;
+
+static pid_t target_pid = 0;
+static bool clear_screen = true;
+static int output_rows = 20;
+static int sort_by = SORT_BY_CACHE_SIZE;
+static int interval = 1;
+static int count = 99999999;
+static bool verbose = false;
+
+const char *argp_program_version = "slabratetop 0.1";
+const char *argp_program_bug_address =
+ "https://github.com/iovisor/bcc/tree/master/libbpf-tools";
+const char argp_program_doc[] =
+"Trace slab kmem cache alloc by process.\n"
+"\n"
+"USAGE: slabratetop [-h] [-p PID] [interval] [count]\n"
+"\n"
+"EXAMPLES:\n"
+" slabratetop # slab rate top, refresh every 1s\n"
+" slabratetop -p 181 # only trace PID 181\n"
+" slabratetop -s count # sort columns by count\n"
+" slabratetop -r 100 # print 100 rows\n"
+" slabratetop 5 10 # 5s summaries, 10 times\n";
+
+static const struct argp_option opts[] = {
+ { "pid", 'p', "PID", 0, "Process ID to trace" },
+ { "noclear", 'C', NULL, 0, "Don't clear the screen" },
+ { "sort", 's', "SORT", 0, "Sort columns, default size [name, count, size]" },
+ { "rows", 'r', "ROWS", 0, "Maximum rows to print, default 20" },
+ { "verbose", 'v', NULL, 0, "Verbose debug output" },
+ { NULL, 'h', NULL, OPTION_HIDDEN, "Show the full help" },
+ {},
+};
+
+static error_t parse_arg(int key, char *arg, struct argp_state *state)
+{
+ long pid, rows;
+ static int pos_args;
+
+ switch (key) {
+ case 'p':
+ errno = 0;
+ pid = strtol(arg, NULL, 10);
+ if (errno || pid <= 0) {
+ warn("invalid PID: %s\n", arg);
+ argp_usage(state);
+ }
+ target_pid = pid;
+ break;
+ case 'C':
+ clear_screen = false;
+ break;
+ case 's':
+ if (!strcmp(arg, "name")) {
+ sort_by = SORT_BY_CACHE_NAME;
+ } else if (!strcmp(arg, "count")) {
+ sort_by = SORT_BY_CACHE_COUNT;
+ } else if (!strcmp(arg, "size")) {
+ sort_by = SORT_BY_CACHE_SIZE;
+ } else {
+ warn("invalid sort method: %s\n", arg);
+ argp_usage(state);
+ }
+ break;
+ case 'r':
+ errno = 0;
+ rows = strtol(arg, NULL, 10);
+ if (errno || rows <= 0) {
+ warn("invalid rows: %s\n", arg);
+ argp_usage(state);
+ }
+ output_rows = rows;
+ if (output_rows > OUTPUT_ROWS_LIMIT)
+ output_rows = OUTPUT_ROWS_LIMIT;
+ break;
+ case 'v':
+ verbose = true;
+ break;
+ case 'h':
+ argp_state_help(state, stderr, ARGP_HELP_STD_HELP);
+ break;
+ case ARGP_KEY_ARG:
+ errno = 0;
+ if (pos_args == 0) {
+ interval = strtol(arg, NULL, 10);
+ if (errno || interval <= 0) {
+ warn("invalid interval\n");
+ argp_usage(state);
+ }
+ } else if (pos_args == 1) {
+ count = strtol(arg, NULL, 10);
+ if (errno || count <= 0) {
+ warn("invalid count\n");
+ argp_usage(state);
+ }
+ } else {
+ warn("unrecognized positional argument: %s\n", arg);
+ argp_usage(state);
+ }
+ pos_args++;
+ break;
+ default:
+ return ARGP_ERR_UNKNOWN;
+ }
+ return 0;
+}
+
+static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
+{
+ if (level == LIBBPF_DEBUG && !verbose)
+ return 0;
+ return vfprintf(stderr, format, args);
+}
+
+static void sig_int(int signo)
+{
+ exiting = 1;
+}
+
+static int sort_column(const void *obj1, const void *obj2)
+{
+ struct slabrate_info *s1 = (struct slabrate_info *)obj1;
+ struct slabrate_info *s2 = (struct slabrate_info *)obj2;
+
+ if (sort_by == SORT_BY_CACHE_NAME) {
+ return strcasecmp(s1->name, s2->name);
+ } else if (sort_by == SORT_BY_CACHE_COUNT) {
+ return s2->count - s1->count;
+ } else if (sort_by == SORT_BY_CACHE_SIZE) {
+ return s2->size - s1->size;
+ } else {
+ return s2->size - s1->size;
+ }
+}
+
+static int print_stat(struct slabratetop_bpf *obj)
+{
+ FILE *f;
+ time_t t;
+ struct tm *tm;
+ char ts[16], buf[256];
+ char *key, **prev_key = NULL;
+ static struct slabrate_info values[OUTPUT_ROWS_LIMIT];
+ int n, i, err = 0, rows = 0;
+ int fd = bpf_map__fd(obj->maps.slab_entries);
+
+ f = fopen("/proc/loadavg", "r");
+ if (f) {
+ time(&t);
+ tm = localtime(&t);
+ strftime(ts, sizeof(ts), "%H:%M:%S", tm);
+ memset(buf, 0 , sizeof(buf));
+ n = fread(buf, 1, sizeof(buf), f);
+ if (n)
+ printf("%8s loadavg: %s\n", ts, buf);
+ fclose(f);
+ }
+
+ printf("%-32s %6s %10s\n", "CACHE", "ALLOCS", "BYTES");
+
+ while (1) {
+ err = bpf_map_get_next_key(fd, prev_key, &key);
+ if (err) {
+ if (errno == ENOENT) {
+ err = 0;
+ break;
+ }
+ warn("bpf_map_get_next_key failed: %s\n", strerror(errno));
+ return err;
+ }
+ err = bpf_map_lookup_elem(fd, &key, &values[rows++]);
+ if (err) {
+ warn("bpf_map_lookup_elem failed: %s\n", strerror(errno));
+ return err;
+ }
+ prev_key = &key;
+ }
+
+ qsort(values, rows, sizeof(struct slabrate_info), sort_column);
+ rows = rows < output_rows ? rows : output_rows;
+ for (i = 0; i < rows; i++)
+ printf("%-32s %6lld %10lld\n",
+ values[i].name, values[i].count, values[i].size);
+
+ printf("\n");
+ prev_key = NULL;
+
+ while (1) {
+ err = bpf_map_get_next_key(fd, prev_key, &key);
+ if (err) {
+ if (errno == ENOENT) {
+ err = 0;
+ break;
+ }
+ warn("bpf_map_get_next_key failed: %s\n", strerror(errno));
+ return err;
+ }
+ err = bpf_map_delete_elem(fd, &key);
+ if (err) {
+ warn("bpf_map_delete_elem failed: %s\n", strerror(errno));
+ return err;
+ }
+ prev_key = &key;
+ }
+ return err;
+}
+
+int main(int argc, char **argv)
+{
+ static const struct argp argp = {
+ .options = opts,
+ .parser = parse_arg,
+ .doc = argp_program_doc,
+ };
+ struct slabratetop_bpf *obj;
+ int err;
+
+ err = argp_parse(&argp, argc, argv, 0, NULL, NULL);
+ if (err)
+ return err;
+
+ libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
+ libbpf_set_print(libbpf_print_fn);
+
+ obj = slabratetop_bpf__open();
+ if (!obj) {
+ warn("failed to open BPF object\n");
+ return 1;
+ }
+
+ obj->rodata->target_pid = target_pid;
+
+ err = slabratetop_bpf__load(obj);
+ if (err) {
+ warn("failed to load BPF object: %d\n", err);
+ goto cleanup;
+ }
+
+ err = slabratetop_bpf__attach(obj);
+ if (err) {
+ warn("failed to attach BPF programs: %d\n", err);
+ goto cleanup;
+ }
+
+ if (signal(SIGINT, sig_int) == SIG_ERR) {
+ warn("can't set signal handler: %s\n", strerror(errno));
+ err = 1;
+ goto cleanup;
+ }
+
+ while (1) {
+ sleep(interval);
+
+ if (clear_screen) {
+ err = system("clear");
+ if (err)
+ goto cleanup;
+ }
+
+ err = print_stat(obj);
+ if (err)
+ goto cleanup;
+
+ count--;
+ if (exiting || !count)
+ goto cleanup;
+ }
+
+cleanup:
+ slabratetop_bpf__destroy(obj);
+
+ return err != 0;
+}

libbpf-tools/slabratetop.h

@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+#ifndef __SLABRATETOP_H
+#define __SLABRATETOP_H
+
+#define CACHE_NAME_SIZE 32
+
+struct slabrate_info {
+ char name[CACHE_NAME_SIZE];
+ __u64 count;
+ __u64 size;
+};
+
+#endif /* __SLABRATETOP_H */