Commit eeb399b5 authored by Adrian Hunter's avatar Adrian Hunter Committed by Arnaldo Carvalho de Melo

perf record: Put a copy of kcore into the perf.data directory

Add a new 'perf record' option '--kcore' which will put a copy of
/proc/kcore, kallsyms and modules into a perf.data directory. Note, that
without the --kcore option, output goes to a file as previously.  The
tools' -o and -i options work with either a file name or directory name.

Example:

  $ sudo perf record --kcore uname

  $ sudo tree perf.data
  perf.data
  ├── kcore_dir
  │   ├── kallsyms
  │   ├── kcore
  │   └── modules
  └── data

  $ sudo perf script -v
  build id event received for vmlinux: 1eaa285996affce2d74d8e66dcea09a80c9941de
  build id event received for [vdso]: 8bbaf5dc62a9b644b4d4e4539737e104e4a84541
  Samples for 'cycles' event do not have CPU attribute set. Skipping 'cpu' field.
  Using CPUID GenuineIntel-6-8E-A
  Using perf.data/kcore_dir/kcore for kernel data
  Using perf.data/kcore_dir/kallsyms for symbols
             perf 19058 506778.423729:          1 cycles:  ffffffffa2caa548 native_write_msr+0x8 (vmlinux)
             perf 19058 506778.423733:          1 cycles:  ffffffffa2caa548 native_write_msr+0x8 (vmlinux)
             perf 19058 506778.423734:          7 cycles:  ffffffffa2caa548 native_write_msr+0x8 (vmlinux)
             perf 19058 506778.423736:        117 cycles:  ffffffffa2caa54a native_write_msr+0xa (vmlinux)
             perf 19058 506778.423738:       2092 cycles:  ffffffffa2c9b7b0 native_apic_msr_write+0x0 (vmlinux)
             perf 19058 506778.423740:      37380 cycles:  ffffffffa2f121d0 perf_event_addr_filters_exec+0x0 (vmlinux)
            uname 19058 506778.423751:     582673 cycles:  ffffffffa303a407 propagate_protected_usage+0x147 (vmlinux)
            uname 19058 506778.423892:    2241841 cycles:  ffffffffa2cae0c9 unwind_next_frame.part.5+0x79 (vmlinux)
            uname 19058 506778.424430:    2457397 cycles:  ffffffffa3019232 check_memory_region+0x52 (vmlinux)

Committer testing:

  # rm -rf perf.data*
  # perf record sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.024 MB perf.data (7 samples) ]
  # ls -l perf.data
  -rw-------. 1 root root 34772 Oct 21 11:08 perf.data
  # perf record --kcore uname
  Linux
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.024 MB perf.data (7 samples) ]
  ls[root@quaco ~]# ls -lad perf.data*
  drwx------. 3 root root  4096 Oct 21 11:08 perf.data
  -rw-------. 1 root root 34772 Oct 21 11:08 perf.data.old
  # perf evlist -v
  cycles: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|PERIOD, read_format: ID, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, enable_on_exec: 1, task: 1, precise_ip: 3, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1
  # perf evlist -v -i perf.data/data
  cycles: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|PERIOD, read_format: ID, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, enable_on_exec: 1, task: 1, precise_ip: 3, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1
  #
Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Reviewed-by: default avatarJiri Olsa <jolsa@kernel.org>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Link: http://lore.kernel.org/lkml/20191004083121.12182-6-adrian.hunter@intel.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 46e201ef
......@@ -571,6 +571,9 @@ config terms. For example: 'cycles/overwrite/' and 'instructions/no-overwrite/'.
Implies --tail-synthesize.
--kcore::
Make a copy of /proc/kcore and place it into a directory with the perf data file.
SEE ALSO
--------
linkperf:perf-stat[1], linkperf:perf-list[1]
......@@ -26,3 +26,38 @@ The current only version value 0 means that:
Future versions are expected to describe different data files
layout according to special needs.
Currently the only 'perf record' option to output to a directory is
the --kcore option which puts a copy of /proc/kcore into the directory.
e.g.
$ sudo perf record --kcore uname
Linux
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.015 MB perf.data (9 samples) ]
$ sudo tree -ps perf.data
perf.data
├── [-rw------- 23744] data
└── [drwx------ 4096] kcore_dir
├── [-r-------- 6731125] kallsyms
├── [-r-------- 40230912] kcore
└── [-r-------- 5419] modules
1 directory, 4 files
$ sudo perf script -v
build id event received for vmlinux: 1eaa285996affce2d74d8e66dcea09a80c9941de
build id event received for [vdso]: 8bbaf5dc62a9b644b4d4e4539737e104e4a84541
build id event received for /lib/x86_64-linux-gnu/libc-2.28.so: 5b157f49586a3ca84d55837f97ff466767dd3445
Samples for 'cycles' event do not have CPU attribute set. Skipping 'cpu' field.
Using CPUID GenuineIntel-6-8E-A
Using perf.data/kcore_dir/kcore for kernel data
Using perf.data/kcore_dir/kallsyms for symbols
perf 15316 2060795.480902: 1 cycles: ffffffffa2caa548 native_write_msr+0x8 (vmlinux)
perf 15316 2060795.480906: 1 cycles: ffffffffa2caa548 native_write_msr+0x8 (vmlinux)
perf 15316 2060795.480908: 7 cycles: ffffffffa2caa548 native_write_msr+0x8 (vmlinux)
perf 15316 2060795.480910: 119 cycles: ffffffffa2caa54a native_write_msr+0xa (vmlinux)
perf 15316 2060795.480912: 2109 cycles: ffffffffa2c9b7b0 native_apic_msr_write+0x0 (vmlinux)
perf 15316 2060795.480914: 37606 cycles: ffffffffa2f121fe perf_event_addr_filters_exec+0x2e (vmlinux)
uname 15316 2060795.480924: 588287 cycles: ffffffffa303a56d page_counter_try_charge+0x6d (vmlinux)
uname 15316 2060795.481067: 2261945 cycles: ffffffffa301438f kmem_cache_free+0x4f (vmlinux)
uname 15316 2060795.481643: 2172167 cycles: 7f1a48c393c0 _IO_un_link+0x0 (/lib/x86_64-linux-gnu/libc-2.28.so)
......@@ -55,6 +55,9 @@
#include <signal.h>
#include <sys/mman.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <linux/err.h>
#include <linux/string.h>
#include <linux/time64.h>
......@@ -699,6 +702,37 @@ static int record__auxtrace_init(struct record *rec __maybe_unused)
#endif
static bool record__kcore_readable(struct machine *machine)
{
char kcore[PATH_MAX];
int fd;
scnprintf(kcore, sizeof(kcore), "%s/proc/kcore", machine->root_dir);
fd = open(kcore, O_RDONLY);
if (fd < 0)
return false;
close(fd);
return true;
}
static int record__kcore_copy(struct machine *machine, struct perf_data *data)
{
char from_dir[PATH_MAX];
char kcore_dir[PATH_MAX];
int ret;
snprintf(from_dir, sizeof(from_dir), "%s/proc", machine->root_dir);
ret = perf_data__make_kcore_dir(data, kcore_dir, sizeof(kcore_dir));
if (ret)
return ret;
return kcore_copy(from_dir, kcore_dir);
}
static int record__mmap_evlist(struct record *rec,
struct evlist *evlist)
{
......@@ -1383,6 +1417,12 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
session->header.env.comp_type = PERF_COMP_ZSTD;
session->header.env.comp_level = rec->opts.comp_level;
if (rec->opts.kcore &&
!record__kcore_readable(&session->machines.host)) {
pr_err("ERROR: kcore is not readable.\n");
return -1;
}
record__init_features(rec);
if (rec->opts.use_clockid && rec->opts.clockid_res_ns)
......@@ -1414,6 +1454,14 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
}
session->header.env.comp_mmap_len = session->evlist->core.mmap_len;
if (rec->opts.kcore) {
err = record__kcore_copy(&session->machines.host, data);
if (err) {
pr_err("ERROR: Failed to copy kcore\n");
goto out_child;
}
}
err = bpf__apply_obj_config();
if (err) {
char errbuf[BUFSIZ];
......@@ -2184,6 +2232,7 @@ static struct option __record_options[] = {
parse_cgroups),
OPT_UINTEGER('D', "delay", &record.opts.initial_delay,
"ms to wait before starting measurement after program start"),
OPT_BOOLEAN(0, "kcore", &record.opts.kcore, "copy /proc/kcore"),
OPT_STRING('u', "uid", &record.opts.target.uid_str, "user",
"user to profile"),
......@@ -2322,6 +2371,9 @@ int cmd_record(int argc, const char **argv)
}
if (rec->opts.kcore)
rec->data.is_dir = true;
if (rec->opts.comp_level != 0) {
pr_debug("Compression enabled, disabling build id collection at the end of the session.\n");
rec->no_buildid = true;
......
......@@ -424,3 +424,36 @@ unsigned long perf_data__size(struct perf_data *data)
return size;
}
int perf_data__make_kcore_dir(struct perf_data *data, char *buf, size_t buf_sz)
{
int ret;
if (!data->is_dir)
return -1;
ret = snprintf(buf, buf_sz, "%s/kcore_dir", data->path);
if (ret < 0 || (size_t)ret >= buf_sz)
return -1;
return mkdir(buf, S_IRWXU);
}
char *perf_data__kallsyms_name(struct perf_data *data)
{
char *kallsyms_name;
struct stat st;
if (!data->is_dir)
return NULL;
if (asprintf(&kallsyms_name, "%s/kcore_dir/kallsyms", data->path) < 0)
return NULL;
if (stat(kallsyms_name, &st)) {
free(kallsyms_name);
return NULL;
}
return kallsyms_name;
}
......@@ -87,4 +87,6 @@ int perf_data__open_dir(struct perf_data *data);
void perf_data__close_dir(struct perf_data *data);
int perf_data__update_dir(struct perf_data *data);
unsigned long perf_data__size(struct perf_data *data);
int perf_data__make_kcore_dir(struct perf_data *data, char *buf, size_t buf_sz);
char *perf_data__kallsyms_name(struct perf_data *data);
#endif /* __PERF_DATA_H */
......@@ -44,6 +44,7 @@ struct record_opts {
bool strict_freq;
bool sample_id;
bool no_bpf_event;
bool kcore;
unsigned int freq;
unsigned int mmap_pages;
unsigned int auxtrace_mmap_pages;
......
......@@ -230,6 +230,10 @@ struct perf_session *perf_session__new(struct perf_data *data,
if (ret)
goto out_delete;
}
if (!symbol_conf.kallsyms_name &&
!symbol_conf.vmlinux_name)
symbol_conf.kallsyms_name = perf_data__kallsyms_name(data);
}
} else {
session->machines.host.env = &perf_env;
......
......@@ -182,6 +182,21 @@ static int rm_rf_depth_pat(const char *path, int depth, const char **pat)
return rmdir(path);
}
static int rm_rf_kcore_dir(const char *path)
{
char kcore_dir_path[PATH_MAX];
const char *pat[] = {
"kcore",
"kallsyms",
"modules",
NULL,
};
snprintf(kcore_dir_path, sizeof(kcore_dir_path), "%s/kcore_dir", path);
return rm_rf_depth_pat(kcore_dir_path, 0, pat);
}
int rm_rf_perf_data(const char *path)
{
const char *pat[] = {
......@@ -190,6 +205,8 @@ int rm_rf_perf_data(const char *path)
NULL,
};
rm_rf_kcore_dir(path);
return rm_rf_depth_pat(path, 0, pat);
}
......
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