Hi Arnaldo,
On Wed, Dec 24, 2014 at 10:51 PM, Arnaldo Carvalho de Melo
<a...@kernel.org> wrote:
> Em Wed, Dec 24, 2014 at 04:15:33PM +0900, Namhyung Kim escreveu:
>> The perf data split command is for splitting a (large) single data
>> file into multiple files under a directory (perf.data.dir by default)
>> so that it can be processed and reported using multiple threads.
>
> How is it split? By CPU?
> Will the metadata stay in a different file?
> Please be as verbose on the description as possible :-)
It depends on the data file - if it's recorded system-wide, the split
will be done by cpu, otherwise by thread. It's determined by checking
sample type has PERF_SAMPLE_CPU. And metadata is saved in a separate
perf.header file like other multi-file data. Will add it to the
change log.
Thanks,
Namhyung
>> Signed-off-by: Namhyung Kim <namhy...@kernel.org>
>> ---
>> tools/perf/Documentation/perf-data.txt | 28 +++++
>> tools/perf/builtin-data.c | 223
>> +++++++++++++++++++++++++++++++++
>> 2 files changed, 251 insertions(+)
>>
>> diff --git a/tools/perf/Documentation/perf-data.txt
>> b/tools/perf/Documentation/perf-data.txt
>> index b8c83947715c..42708702f10c 100644
>> --- a/tools/perf/Documentation/perf-data.txt
>> +++ b/tools/perf/Documentation/perf-data.txt
>> @@ -13,3 +13,31 @@ SYNOPSIS
>> DESCRIPTION
>> -----------
>> Data file related processing.
>> +
>> +COMMANDS
>> +--------
>> +split::
>> + Split single data file (perf.data) into multiple files under a
>> directory
>> + in order to be reported by multiple threads.
>> +
>> +OPTIONS for 'split'
>> +---------------------
>> +-i::
>> +--input::
>> + Specify input perf data file path.
>> +
>> +-o::
>> +--output::
>> + Specify output perf data directory path.
>> +
>> +-v::
>> +--verbose::
>> + Be more verbose (show counter open errors, etc).
>> +
>> +-f::
>> +--force::
>> + Don't complain, do it.
>> +
>> +SEE ALSO
>> +--------
>> +linkperf:perf[1], linkperf:perf-report[1]
>> diff --git a/tools/perf/builtin-data.c b/tools/perf/builtin-data.c
>> index 1eee97d020fa..5f3173826850 100644
>> --- a/tools/perf/builtin-data.c
>> +++ b/tools/perf/builtin-data.c
>> @@ -2,10 +2,14 @@
>> #include "builtin.h"
>> #include "perf.h"
>> #include "debug.h"
>> +#include "session.h"
>> +#include "evlist.h"
>> #include "parse-options.h"
>>
>> typedef int (*data_cmd_fn_t)(int argc, const char **argv, const char
>> *prefix);
>>
>> +static const char *output_name;
>> +
>> struct data_cmd {
>> const char *name;
>> const char *summary;
>> @@ -41,10 +45,229 @@ static void print_usage(void)
>> printf("\n");
>> }
>>
>> +static int data_cmd_split(int argc, const char **argv, const char *prefix);
>> +
>> static struct data_cmd data_cmds[] = {
>> + { "split", "split single data file into multi-file", data_cmd_split },
>> { NULL },
>> };
>>
>> +#define FD_HASH_BITS 7
>> +#define FD_HASH_SIZE (1 << FD_HASH_BITS)
>> +#define FD_HASH_MASK (FD_HASH_SIZE - 1)
>> +
>> +struct data_split {
>> + struct perf_tool tool;
>> + struct perf_session *session;
>> + enum {
>> + PER_CPU,
>> + PER_THREAD,
>> + } mode;
>> + int header_fd;
>> + u64 header_written;
>> + struct hlist_head fd_hash[FD_HASH_SIZE];
>> + int fd_hash_nr;
>> +};
>> +
>> +struct fdhash_node {
>> + int id;
>> + int fd;
>> + struct hlist_node list;
>> +};
>> +
>> +static struct hlist_head *get_hash(struct data_split *split, int id)
>> +{
>> + return &split->fd_hash[id % FD_HASH_MASK];
>> +}
>> +
>> +static int perf_event__rewrite_header(struct perf_tool *tool,
>> + union perf_event *event)
>> +{
>> + struct data_split *split = container_of(tool, struct data_split, tool);
>> + ssize_t size;
>> +
>> + size = writen(split->header_fd, event, event->header.size);
>> + if (size < 0)
>> + return -errno;
>> +
>> + split->header_written += size;
>> + return 0;
>> +}
>> +
>> +static int split_other_events(struct perf_tool *tool,
>> + union perf_event *event,
>> + struct perf_sample *sample __maybe_unused,
>> + struct machine *machine __maybe_unused)
>> +{
>> + return perf_event__rewrite_header(tool, event);
>> +}
>> +
>> +static int split_sample_event(struct perf_tool *tool,
>> + union perf_event *event,
>> + struct perf_sample *sample,
>> + struct perf_evsel *evsel __maybe_unused,
>> + struct machine *machine __maybe_unused)
>> +{
>> + struct data_split *split = container_of(tool, struct data_split, tool);
>> + int id = split->mode == PER_CPU ? sample->cpu : sample->tid;
>> + int fd = -1;
>> + char buf[PATH_MAX];
>> + struct hlist_head *head;
>> + struct fdhash_node *node;
>> +
>> + head = get_hash(split, id);
>> + hlist_for_each_entry(node, head, list) {
>> + if (node->id == id) {
>> + fd = node->fd;
>> + break;
>> + }
>> + }
>> +
>> + if (fd == -1) {
>> + scnprintf(buf, sizeof(buf), "%s/perf.data.%d",
>> + output_name, split->fd_hash_nr++);
>> +
>> + fd = open(buf, O_RDWR|O_CREAT|O_TRUNC, 0600);
>> + if (fd < 0) {
>> + pr_err("cannot open data file: %s: %m\n", buf);
>> + return -1;
>> + }
>> +
>> + node = malloc(sizeof(*node));
>> + if (node == NULL) {
>> + pr_err("memory allocation failed\n");
>> + return -1;
>> + }
>> +
>> + node->id = id;
>> + node->fd = fd;
>> +
>> + hlist_add_head(&node->list, head);
>> + }
>> +
>> + return writen(fd, event, event->header.size) > 0 ? 0 : -errno;
>> +}
>> +
>> +static int __data_cmd_split(struct data_split *split)
>> +{
>> + struct perf_session *session = split->session;
>> + char *output = NULL;
>> + char buf[PATH_MAX];
>> + u64 sample_type;
>> + int header_fd;
>> + int ret = -1;
>> + int i;
>> +
>> + if (!output_name) {
>> + if (asprintf(&output, "%s.dir", input_name) < 0) {
>> + pr_err("memory allocation failed\n");
>> + return -1;
>> + }
>> + output_name = output;
>> + }
>> +
>> + mkdir(output_name, 0700);
>> +
>> + /*
>> + * This is necessary to write (copy) build-id table. After
>> + * processing header, dsos list will contain dso which was on
>> + * the original build-id table.
>> + */
>> + dsos__hit_all(session);
>> +
>> + scnprintf(buf, sizeof(buf), "%s/perf.header", output_name);
>> + header_fd = open(buf, O_RDWR|O_CREAT|O_TRUNC, 0600);
>> + if (header_fd < 0) {
>> + pr_err("cannot open header file: %s: %m\n", buf);
>> + goto out;
>> + }
>> +
>> + lseek(header_fd, session->header.data_offset, SEEK_SET);
>> +
>> + sample_type = perf_evlist__combined_sample_type(session->evlist);
>> + if (sample_type & PERF_SAMPLE_CPU)
>> + split->mode = PER_CPU;
>> + else
>> + split->mode = PER_THREAD;
>> +
>> + pr_debug("splitting data file for %s\n",
>> + split->mode == PER_CPU ? "CPUs" : "threads");
>> +
>> + split->header_fd = header_fd;
>> + perf_session__process_events(session, &split->tool);
>> +
>> + for (i = 0; i < FD_HASH_SIZE; i++) {
>> + struct fdhash_node *pos;
>> + struct hlist_node *tmp;
>> +
>> + hlist_for_each_entry_safe(pos, tmp, &split->fd_hash[i], list) {
>> + hlist_del(&pos->list);
>> + close(pos->fd);
>> + free(pos);
>> + }
>> + }
>> +
>> + session->header.data_size = split->header_written;
>> + perf_session__write_header(session, session->evlist, header_fd, true);
>> +
>> + close(header_fd);
>> + ret = 0;
>> +out:
>> + free(output);
>> + return ret;
>> +}
>> +
>> +int data_cmd_split(int argc, const char **argv, const char *prefix
>> __maybe_unused)
>> +{
>> + bool force = false;
>> + struct perf_session *session;
>> + struct perf_data_file file = {
>> + .mode = PERF_DATA_MODE_READ,
>> + };
>> + struct data_split split = {
>> + .tool = {
>> + .sample = split_sample_event,
>> + .fork = split_other_events,
>> + .comm = split_other_events,
>> + .exit = split_other_events,
>> + .mmap = split_other_events,
>> + .mmap2 = split_other_events,
>> + .lost = split_other_events,
>> + .throttle = split_other_events,
>> + .unthrottle = split_other_events,
>> + },
>> + };
>> + const char * const split_usage[] = {
>> + "perf data split [<options>]",
>> + NULL
>> + };
>> + const struct option split_options[] = {
>> + OPT_STRING('i', "input", &input_name, "file", "input file name"),
>> + OPT_STRING('o', "output", &output_name, "file", "output directory
>> name"),
>> + OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
>> + OPT_INCR('v', "verbose", &verbose, "be more verbose"),
>> + OPT_END()
>> + };
>> +
>> + argc = parse_options(argc, argv, split_options, split_usage, 0);
>> + if (argc)
>> + usage_with_options(split_usage, split_options);
>> +
>> + file.path = input_name;
>> + file.force = force;
>> + session = perf_session__new(&file, false, &split.tool);
>> + if (session == NULL)
>> + return -1;
>> +
>> + split.session = session;
>> + symbol__init(&session->header.env);
>> +
>> + __data_cmd_split(&split);
>> +
>> + perf_session__delete(session);
>> + return 0;
>> +}
>> +
>> int cmd_data(int argc, const char **argv, const char *prefix)
>> {
>> struct data_cmd *cmd;
>> --
>> 2.1.3
--
Thanks,
Namhyung
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