perf: Add 'perf kmem' tool
authorLi Zefan <lizf@cn.fujitsu.com>
Fri, 20 Nov 2009 07:53:25 +0000 (15:53 +0800)
committerIngo Molnar <mingo@elte.hu>
Fri, 20 Nov 2009 08:51:41 +0000 (09:51 +0100)
This tool is mostly a perf version of kmemtrace-user.

The following information is provided by this tool:

 - the total amount of memory allocated and fragmentation per
   call-site

 - the total amount of memory allocated and fragmentation per
   allocation

 - total memory allocated and fragmentation in the collected
   dataset - ...

Sample output:

 # ./perf kmem record
 ^C
 # ./perf kmem --stat caller --stat alloc -l 10

 ------------------------------------------------------------------------------
 Callsite          | Total_alloc/Per |  Total_req/Per  |  Hit   | Fragmentation
 ------------------------------------------------------------------------------
 0xc052f37a        |   790528/4096   |   790528/4096   |    193 |    0.000%
 0xc0541d70        |   524288/4096   |   524288/4096   |    128 |    0.000%
 0xc051cc68        |   481600/200    |   481600/200    |   2408 |    0.000%
 0xc0572623        |   297444/676    |   297440/676    |    440 |    0.001%
 0xc05399f1        |    73476/164    |    73472/164    |    448 |    0.005%
 0xc05243bf        |    51456/256    |    51456/256    |    201 |    0.000%
 0xc0730d0e        |    31844/497    |    31808/497    |     64 |    0.113%
 0xc0734c4e        |    17152/256    |    17152/256    |     67 |    0.000%
 0xc0541a6d        |    16384/128    |    16384/128    |    128 |    0.000%
 0xc059c217        |    13120/40     |    13120/40     |    328 |    0.000%
 0xc0501ee6        |    11264/88     |    11264/88     |    128 |    0.000%
 0xc04daef0        |     7504/682    |     7128/648    |     11 |    5.011%
 0xc04e14a3        |     4216/191    |     4216/191    |     22 |    0.000%
 0xc05041ca        |     3524/44     |     3520/44     |     80 |    0.114%
 0xc0734fa3        |     2104/701    |     1620/540    |      3 |   23.004%
 0xc05ec9f1        |     2024/289    |     2016/288    |      7 |    0.395%
 0xc06a1999        |     1792/256    |     1792/256    |      7 |    0.000%
 0xc0463b9a        |     1584/144    |     1584/144    |     11 |    0.000%
 0xc0541eb0        |     1024/16     |     1024/16     |     64 |    0.000%
 0xc06a19ac        |      896/128    |      896/128    |      7 |    0.000%
 0xc05721c0        |      772/12     |      768/12     |     64 |    0.518%
 0xc054d1e6        |      288/57     |      280/56     |      5 |    2.778%
 0xc04b562e        |      157/31     |      154/30     |      5 |    1.911%
 0xc04b536f        |       80/16     |       80/16     |      5 |    0.000%
 0xc05855a0        |       64/64     |       36/36     |      1 |   43.750%
 ------------------------------------------------------------------------------

 ------------------------------------------------------------------------------
 Alloc Ptr         | Total_alloc/Per |  Total_req/Per  |  Hit   | Fragmentation
 ------------------------------------------------------------------------------
 0xda884000        |  1052672/4096   |  1052672/4096   |    257 |    0.000%
 0xda886000        |   262144/4096   |   262144/4096   |     64 |    0.000%
 0xf60c7c00        |    16512/128    |    16512/128    |    129 |    0.000%
 0xf59a4118        |    13120/40     |    13120/40     |    328 |    0.000%
 0xdfd4b2c0        |    11264/88     |    11264/88     |    128 |    0.000%
 0xf5274600        |     7680/256    |     7680/256    |     30 |    0.000%
 0xe8395000        |     5948/594    |     5464/546    |     10 |    8.137%
 0xe59c3c00        |     5748/479    |     5712/476    |     12 |    0.626%
 0xf4cd1a80        |     3524/44     |     3520/44     |     80 |    0.114%
 0xe5bd1600        |     2892/482    |     2856/476    |      6 |    1.245%
 ...               | ...             | ...             | ...    | ...
 ------------------------------------------------------------------------------

SUMMARY
=======
Total bytes requested: 2333626
Total bytes allocated: 2353712
Total bytes wasted on internal fragmentation: 20086
Internal fragmentation: 0.853375%

TODO:
- show sym+offset in 'callsite' column
- show cross node allocation stats
- collect more useful stats?
- ...

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: linux-mm@kvack.org <linux-mm@kvack.org>
LKML-Reference: <4B064AF5.9060208@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
tools/perf/Makefile
tools/perf/builtin-kmem.c [new file with mode: 0644]
tools/perf/builtin.h
tools/perf/perf.c

index 3f0666a..d7198c5 100644 (file)
@@ -444,6 +444,7 @@ BUILTIN_OBJS += builtin-timechart.o
 BUILTIN_OBJS += builtin-top.o
 BUILTIN_OBJS += builtin-trace.o
 BUILTIN_OBJS += builtin-probe.o
+BUILTIN_OBJS += builtin-kmem.o
 
 PERFLIBS = $(LIB_FILE)
 
diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c
new file mode 100644 (file)
index 0000000..f315b05
--- /dev/null
@@ -0,0 +1,578 @@
+#include "builtin.h"
+#include "perf.h"
+
+#include "util/util.h"
+#include "util/cache.h"
+#include "util/symbol.h"
+#include "util/thread.h"
+#include "util/header.h"
+
+#include "util/parse-options.h"
+#include "util/trace-event.h"
+
+#include "util/debug.h"
+#include "util/data_map.h"
+
+#include <linux/rbtree.h>
+
+struct alloc_stat;
+typedef int (*sort_fn_t)(struct alloc_stat *, struct alloc_stat *);
+
+static char const              *input_name = "perf.data";
+
+static struct perf_header      *header;
+static u64                     sample_type;
+
+static int                     alloc_flag;
+static int                     caller_flag;
+
+sort_fn_t                      alloc_sort_fn;
+sort_fn_t                      caller_sort_fn;
+
+static int                     alloc_lines = -1;
+static int                     caller_lines = -1;
+
+static char                    *cwd;
+static int                     cwdlen;
+
+struct alloc_stat {
+       union {
+               struct {
+                       char    *name;
+                       u64     call_site;
+               };
+               u64     ptr;
+       };
+       u64     bytes_req;
+       u64     bytes_alloc;
+       u32     hit;
+
+       struct rb_node node;
+};
+
+static struct rb_root root_alloc_stat;
+static struct rb_root root_alloc_sorted;
+static struct rb_root root_caller_stat;
+static struct rb_root root_caller_sorted;
+
+static unsigned long total_requested, total_allocated;
+
+struct raw_event_sample {
+       u32 size;
+       char data[0];
+};
+
+static int
+process_comm_event(event_t *event, unsigned long offset, unsigned long head)
+{
+       struct thread *thread = threads__findnew(event->comm.pid);
+
+       dump_printf("%p [%p]: PERF_RECORD_COMM: %s:%d\n",
+               (void *)(offset + head),
+               (void *)(long)(event->header.size),
+               event->comm.comm, event->comm.pid);
+
+       if (thread == NULL ||
+           thread__set_comm(thread, event->comm.comm)) {
+               dump_printf("problem processing PERF_RECORD_COMM, skipping event.\n");
+               return -1;
+       }
+
+       return 0;
+}
+
+static void insert_alloc_stat(unsigned long ptr,
+                             int bytes_req, int bytes_alloc)
+{
+       struct rb_node **node = &root_alloc_stat.rb_node;
+       struct rb_node *parent = NULL;
+       struct alloc_stat *data = NULL;
+
+       if (!alloc_flag)
+               return;
+
+       while (*node) {
+               parent = *node;
+               data = rb_entry(*node, struct alloc_stat, node);
+
+               if (ptr > data->ptr)
+                       node = &(*node)->rb_right;
+               else if (ptr < data->ptr)
+                       node = &(*node)->rb_left;
+               else
+                       break;
+       }
+
+       if (data && data->ptr == ptr) {
+               data->hit++;
+               data->bytes_req += bytes_req;
+               data->bytes_alloc += bytes_req;
+       } else {
+               data = malloc(sizeof(*data));
+               data->ptr = ptr;
+               data->hit = 1;
+               data->bytes_req = bytes_req;
+               data->bytes_alloc = bytes_alloc;
+
+               rb_link_node(&data->node, parent, node);
+               rb_insert_color(&data->node, &root_alloc_stat);
+       }
+}
+
+static void insert_caller_stat(unsigned long call_site,
+                             int bytes_req, int bytes_alloc)
+{
+       struct rb_node **node = &root_caller_stat.rb_node;
+       struct rb_node *parent = NULL;
+       struct alloc_stat *data = NULL;
+
+       if (!caller_flag)
+               return;
+
+       while (*node) {
+               parent = *node;
+               data = rb_entry(*node, struct alloc_stat, node);
+
+               if (call_site > data->call_site)
+                       node = &(*node)->rb_right;
+               else if (call_site < data->call_site)
+                       node = &(*node)->rb_left;
+               else
+                       break;
+       }
+
+       if (data && data->call_site == call_site) {
+               data->hit++;
+               data->bytes_req += bytes_req;
+               data->bytes_alloc += bytes_req;
+       } else {
+               data = malloc(sizeof(*data));
+               data->call_site = call_site;
+               data->hit = 1;
+               data->bytes_req = bytes_req;
+               data->bytes_alloc = bytes_alloc;
+
+               rb_link_node(&data->node, parent, node);
+               rb_insert_color(&data->node, &root_caller_stat);
+       }
+}
+
+static void process_alloc_event(struct raw_event_sample *raw,
+                               struct event *event,
+                               int cpu __used,
+                               u64 timestamp __used,
+                               struct thread *thread __used,
+                               int node __used)
+{
+       unsigned long call_site;
+       unsigned long ptr;
+       int bytes_req;
+       int bytes_alloc;
+
+       ptr = raw_field_value(event, "ptr", raw->data);
+       call_site = raw_field_value(event, "call_site", raw->data);
+       bytes_req = raw_field_value(event, "bytes_req", raw->data);
+       bytes_alloc = raw_field_value(event, "bytes_alloc", raw->data);
+
+       insert_alloc_stat(ptr, bytes_req, bytes_alloc);
+       insert_caller_stat(call_site, bytes_req, bytes_alloc);
+
+       total_requested += bytes_req;
+       total_allocated += bytes_alloc;
+}
+
+static void process_free_event(struct raw_event_sample *raw __used,
+                              struct event *event __used,
+                              int cpu __used,
+                              u64 timestamp __used,
+                              struct thread *thread __used)
+{
+}
+
+static void
+process_raw_event(event_t *raw_event __used, void *more_data,
+                 int cpu, u64 timestamp, struct thread *thread)
+{
+       struct raw_event_sample *raw = more_data;
+       struct event *event;
+       int type;
+
+       type = trace_parse_common_type(raw->data);
+       event = trace_find_event(type);
+
+       if (!strcmp(event->name, "kmalloc") ||
+           !strcmp(event->name, "kmem_cache_alloc")) {
+               process_alloc_event(raw, event, cpu, timestamp, thread, 0);
+               return;
+       }
+
+       if (!strcmp(event->name, "kmalloc_node") ||
+           !strcmp(event->name, "kmem_cache_alloc_node")) {
+               process_alloc_event(raw, event, cpu, timestamp, thread, 1);
+               return;
+       }
+
+       if (!strcmp(event->name, "kfree") ||
+           !strcmp(event->name, "kmem_cache_free")) {
+               process_free_event(raw, event, cpu, timestamp, thread);
+               return;
+       }
+}
+
+static int
+process_sample_event(event_t *event, unsigned long offset, unsigned long head)
+{
+       u64 ip = event->ip.ip;
+       u64 timestamp = -1;
+       u32 cpu = -1;
+       u64 period = 1;
+       void *more_data = event->ip.__more_data;
+       struct thread *thread = threads__findnew(event->ip.pid);
+
+       if (sample_type & PERF_SAMPLE_TIME) {
+               timestamp = *(u64 *)more_data;
+               more_data += sizeof(u64);
+       }
+
+       if (sample_type & PERF_SAMPLE_CPU) {
+               cpu = *(u32 *)more_data;
+               more_data += sizeof(u32);
+               more_data += sizeof(u32); /* reserved */
+       }
+
+       if (sample_type & PERF_SAMPLE_PERIOD) {
+               period = *(u64 *)more_data;
+               more_data += sizeof(u64);
+       }
+
+       dump_printf("%p [%p]: PERF_RECORD_SAMPLE (IP, %d): %d/%d: %p period: %Ld\n",
+               (void *)(offset + head),
+               (void *)(long)(event->header.size),
+               event->header.misc,
+               event->ip.pid, event->ip.tid,
+               (void *)(long)ip,
+               (long long)period);
+
+       if (thread == NULL) {
+               pr_debug("problem processing %d event, skipping it.\n",
+                        event->header.type);
+               return -1;
+       }
+
+       dump_printf(" ... thread: %s:%d\n", thread->comm, thread->pid);
+
+       process_raw_event(event, more_data, cpu, timestamp, thread);
+
+       return 0;
+}
+
+static int sample_type_check(u64 type)
+{
+       sample_type = type;
+
+       if (!(sample_type & PERF_SAMPLE_RAW)) {
+               fprintf(stderr,
+                       "No trace sample to read. Did you call perf record "
+                       "without -R?");
+               return -1;
+       }
+
+       return 0;
+}
+
+static struct perf_file_handler file_handler = {
+       .process_sample_event   = process_sample_event,
+       .process_comm_event     = process_comm_event,
+       .sample_type_check      = sample_type_check,
+};
+
+static int read_events(void)
+{
+       register_idle_thread();
+       register_perf_file_handler(&file_handler);
+
+       return mmap_dispatch_perf_file(&header, input_name, 0, 0,
+                                      &cwdlen, &cwd);
+}
+
+static double fragmentation(unsigned long n_req, unsigned long n_alloc)
+{
+       if (n_alloc == 0)
+               return 0.0;
+       else
+               return 100.0 - (100.0 * n_req / n_alloc);
+}
+
+static void __print_result(struct rb_root *root, int n_lines, int is_caller)
+{
+       struct rb_node *next;
+
+       printf("\n ------------------------------------------------------------------------------\n");
+       if (is_caller)
+               printf(" Callsite          |");
+       else
+               printf(" Alloc Ptr         |");
+       printf(" Total_alloc/Per |  Total_req/Per  |  Hit   | Fragmentation\n");
+       printf(" ------------------------------------------------------------------------------\n");
+
+       next = rb_first(root);
+
+       while (next && n_lines--) {
+               struct alloc_stat *data;
+
+               data = rb_entry(next, struct alloc_stat, node);
+
+               printf(" %-16p  | %8llu/%-6lu | %8llu/%-6lu | %6lu | %8.3f%%\n",
+                      is_caller ? (void *)(unsigned long)data->call_site :
+                                  (void *)(unsigned long)data->ptr,
+                      (unsigned long long)data->bytes_alloc,
+                      (unsigned long)data->bytes_alloc / data->hit,
+                      (unsigned long long)data->bytes_req,
+                      (unsigned long)data->bytes_req / data->hit,
+                      (unsigned long)data->hit,
+                      fragmentation(data->bytes_req, data->bytes_alloc));
+
+               next = rb_next(next);
+       }
+
+       if (n_lines == -1)
+               printf(" ...               | ...             | ...             | ...    | ...   \n");
+
+       printf(" ------------------------------------------------------------------------------\n");
+}
+
+static void print_summary(void)
+{
+       printf("\nSUMMARY\n=======\n");
+       printf("Total bytes requested: %lu\n", total_requested);
+       printf("Total bytes allocated: %lu\n", total_allocated);
+       printf("Total bytes wasted on internal fragmentation: %lu\n",
+              total_allocated - total_requested);
+       printf("Internal fragmentation: %f%%\n",
+              fragmentation(total_requested, total_allocated));
+}
+
+static void print_result(void)
+{
+       if (caller_flag)
+               __print_result(&root_caller_sorted, caller_lines, 1);
+       if (alloc_flag)
+               __print_result(&root_alloc_sorted, alloc_lines, 0);
+       print_summary();
+}
+
+static void sort_insert(struct rb_root *root, struct alloc_stat *data,
+                       sort_fn_t sort_fn)
+{
+       struct rb_node **new = &(root->rb_node);
+       struct rb_node *parent = NULL;
+
+       while (*new) {
+               struct alloc_stat *this;
+               int cmp;
+
+               this = rb_entry(*new, struct alloc_stat, node);
+               parent = *new;
+
+               cmp = sort_fn(data, this);
+
+               if (cmp > 0)
+                       new = &((*new)->rb_left);
+               else
+                       new = &((*new)->rb_right);
+       }
+
+       rb_link_node(&data->node, parent, new);
+       rb_insert_color(&data->node, root);
+}
+
+static void __sort_result(struct rb_root *root, struct rb_root *root_sorted,
+                         sort_fn_t sort_fn)
+{
+       struct rb_node *node;
+       struct alloc_stat *data;
+
+       for (;;) {
+               node = rb_first(root);
+               if (!node)
+                       break;
+
+               rb_erase(node, root);
+               data = rb_entry(node, struct alloc_stat, node);
+               sort_insert(root_sorted, data, sort_fn);
+       }
+}
+
+static void sort_result(void)
+{
+       __sort_result(&root_alloc_stat, &root_alloc_sorted, alloc_sort_fn);
+       __sort_result(&root_caller_stat, &root_caller_sorted, caller_sort_fn);
+}
+
+static int __cmd_kmem(void)
+{
+       setup_pager();
+       read_events();
+       sort_result();
+       print_result();
+
+       return 0;
+}
+
+static const char * const kmem_usage[] = {
+       "perf kmem [<options>] {record}",
+       NULL
+};
+
+
+static int ptr_cmp(struct alloc_stat *l, struct alloc_stat *r)
+{
+       if (l->ptr < r->ptr)
+               return -1;
+       else if (l->ptr > r->ptr)
+               return 1;
+       return 0;
+}
+
+static int callsite_cmp(struct alloc_stat *l, struct alloc_stat *r)
+{
+       if (l->call_site < r->call_site)
+               return -1;
+       else if (l->call_site > r->call_site)
+               return 1;
+       return 0;
+}
+
+static int bytes_cmp(struct alloc_stat *l, struct alloc_stat *r)
+{
+       if (l->bytes_alloc < r->bytes_alloc)
+               return -1;
+       else if (l->bytes_alloc > r->bytes_alloc)
+               return 1;
+       return 0;
+}
+
+static int parse_sort_opt(const struct option *opt __used,
+                         const char *arg, int unset __used)
+{
+       sort_fn_t sort_fn;
+
+       if (!arg)
+               return -1;
+
+       if (strcmp(arg, "ptr") == 0)
+               sort_fn = ptr_cmp;
+       else if (strcmp(arg, "call_site") == 0)
+               sort_fn = callsite_cmp;
+       else if (strcmp(arg, "bytes") == 0)
+               sort_fn = bytes_cmp;
+       else
+               return -1;
+
+       if (caller_flag > alloc_flag)
+               caller_sort_fn = sort_fn;
+       else
+               alloc_sort_fn = sort_fn;
+
+       return 0;
+}
+
+static int parse_stat_opt(const struct option *opt __used,
+                         const char *arg, int unset __used)
+{
+       if (!arg)
+               return -1;
+
+       if (strcmp(arg, "alloc") == 0)
+               alloc_flag = (caller_flag + 1);
+       else if (strcmp(arg, "caller") == 0)
+               caller_flag = (alloc_flag + 1);
+       else
+               return -1;
+       return 0;
+}
+
+static int parse_line_opt(const struct option *opt __used,
+                         const char *arg, int unset __used)
+{
+       int lines;
+
+       if (!arg)
+               return -1;
+
+       lines = strtoul(arg, NULL, 10);
+
+       if (caller_flag > alloc_flag)
+               caller_lines = lines;
+       else
+               alloc_lines = lines;
+
+       return 0;
+}
+
+static const struct option kmem_options[] = {
+       OPT_STRING('i', "input", &input_name, "file",
+                  "input file name"),
+       OPT_CALLBACK(0, "stat", NULL, "<alloc>|<caller>",
+                    "stat selector, Pass 'alloc' or 'caller'.",
+                    parse_stat_opt),
+       OPT_CALLBACK('s', "sort", NULL, "key",
+                    "sort by key: ptr, call_site, hit, bytes",
+                    parse_sort_opt),
+       OPT_CALLBACK('l', "line", NULL, "num",
+                    "show n lins",
+                    parse_line_opt),
+       OPT_END()
+};
+
+static const char *record_args[] = {
+       "record",
+       "-a",
+       "-R",
+       "-M",
+       "-f",
+       "-c", "1",
+       "-e", "kmem:kmalloc",
+       "-e", "kmem:kmalloc_node",
+       "-e", "kmem:kfree",
+       "-e", "kmem:kmem_cache_alloc",
+       "-e", "kmem:kmem_cache_alloc_node",
+       "-e", "kmem:kmem_cache_free",
+};
+
+static int __cmd_record(int argc, const char **argv)
+{
+       unsigned int rec_argc, i, j;
+       const char **rec_argv;
+
+       rec_argc = ARRAY_SIZE(record_args) + argc - 1;
+       rec_argv = calloc(rec_argc + 1, sizeof(char *));
+
+       for (i = 0; i < ARRAY_SIZE(record_args); i++)
+               rec_argv[i] = strdup(record_args[i]);
+
+       for (j = 1; j < (unsigned int)argc; j++, i++)
+               rec_argv[i] = argv[j];
+
+       return cmd_record(i, rec_argv, NULL);
+}
+
+int cmd_kmem(int argc, const char **argv, const char *prefix __used)
+{
+       symbol__init(0);
+
+       argc = parse_options(argc, argv, kmem_options, kmem_usage, 0);
+
+       if (argc && !strncmp(argv[0], "rec", 3))
+               return __cmd_record(argc, argv);
+       else if (argc)
+               usage_with_options(kmem_usage, kmem_options);
+
+       if (!alloc_sort_fn)
+               alloc_sort_fn = bytes_cmp;
+       if (!caller_sort_fn)
+               caller_sort_fn = bytes_cmp;
+
+       return __cmd_kmem();
+}
+
index 9b02d85..a3d8bf6 100644 (file)
@@ -28,5 +28,6 @@ extern int cmd_top(int argc, const char **argv, const char *prefix);
 extern int cmd_trace(int argc, const char **argv, const char *prefix);
 extern int cmd_version(int argc, const char **argv, const char *prefix);
 extern int cmd_probe(int argc, const char **argv, const char *prefix);
+extern int cmd_kmem(int argc, const char **argv, const char *prefix);
 
 #endif
index 89b82ac..cf64049 100644 (file)
@@ -285,20 +285,21 @@ static void handle_internal_command(int argc, const char **argv)
 {
        const char *cmd = argv[0];
        static struct cmd_struct commands[] = {
-               { "help", cmd_help, 0 },
-               { "list", cmd_list, 0 },
                { "buildid-list", cmd_buildid_list, 0 },
-               { "record", cmd_record, 0 },
-               { "report", cmd_report, 0 },
-               { "bench", cmd_bench, 0 },
-               { "stat", cmd_stat, 0 },
-               { "timechart", cmd_timechart, 0 },
-               { "top", cmd_top, 0 },
-               { "annotate", cmd_annotate, 0 },
-               { "version", cmd_version, 0 },
-               { "trace", cmd_trace, 0 },
-               { "sched", cmd_sched, 0 },
-               { "probe", cmd_probe, 0 },
+               { "help",       cmd_help,       0 },
+               { "list",       cmd_list,       0 },
+               { "record",     cmd_record,     0 },
+               { "report",     cmd_report,     0 },
+               { "bench",      cmd_bench,      0 },
+               { "stat",       cmd_stat,       0 },
+               { "timechart",  cmd_timechart,  0 },
+               { "top",        cmd_top,        0 },
+               { "annotate",   cmd_annotate,   0 },
+               { "version",    cmd_version,    0 },
+               { "trace",      cmd_trace,      0 },
+               { "sched",      cmd_sched,      0 },
+               { "probe",      cmd_probe,      0 },
+               { "kmem",       cmd_kmem,       0 },
        };
        unsigned int i;
        static const char ext[] = STRIP_EXTENSION;