Re: [PATCH v7 3/6] perf util: Create function to parse time percent

From: Arnaldo Carvalho de Melo
Date: Mon Jan 08 2018 - 09:31:57 EST


Em Fri, Dec 08, 2017 at 09:13:43PM +0800, Jin Yao escreveu:
> Current perf report/script/... have a --time option to limit the time
> range of output. But right now it only supports absolute time.
>
> For easy using, now it can support a percent of time usage.
>
> For example:
>
> 1. Select the second 10% time slice
> perf report --time 10%/2

After applying this patch I'm not being able to get any of these
examples to work:

[root@jouet home]# perf report --header | grep "time of"
# time of first sample : 22947.909226
# time of last sample : 22948.910704
[root@jouet home]#

Then, when I try the first example:

[root@jouet home]# perf report --stdio --time 1%-20%
Invalid time string
# To display the perf.data header info, please use --header/--header-only options.
#
[root@jouet home]#

What am I doing wrong?

> 2. Select from 0% to 10% time slice
> perf report --time 0%-10%
>
> It also support the multiple time ranges.
>
> 3. Select the first and second 10% time slices
> perf report --time 10%/1,10%/2
>
> 4. Select from 0% to 10% and 30% to 40% slices
> perf report --time 0%-10%,30%-40%
>
> Change log:
> -----------
> v4: An issue is found. Following passes.
> perf script --time 10%/10x12321xsdfdasfdsafdsafdsa
>
> Now it uses strtol to replace atoi.
>
> Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
> ---
> tools/perf/util/time-utils.c | 205 ++++++++++++++++++++++++++++++++++++++++---
> tools/perf/util/time-utils.h | 3 +
> 2 files changed, 196 insertions(+), 12 deletions(-)
>
> diff --git a/tools/perf/util/time-utils.c b/tools/perf/util/time-utils.c
> index 81927d0..61c46022 100644
> --- a/tools/perf/util/time-utils.c
> +++ b/tools/perf/util/time-utils.c
> @@ -6,6 +6,7 @@
> #include <time.h>
> #include <errno.h>
> #include <inttypes.h>
> +#include <math.h>
>
> #include "perf.h"
> #include "debug.h"
> @@ -60,11 +61,10 @@ static int parse_timestr_sec_nsec(struct perf_time_interval *ptime,
> return 0;
> }
>
> -int perf_time__parse_str(struct perf_time_interval *ptime, const char *ostr)
> +static int split_start_end(char **start, char **end, const char *ostr, char ch)
> {
> char *start_str, *end_str;
> char *d, *str;
> - int rc = 0;
>
> if (ostr == NULL || *ostr == '\0')
> return 0;
> @@ -74,25 +74,35 @@ int perf_time__parse_str(struct perf_time_interval *ptime, const char *ostr)
> if (str == NULL)
> return -ENOMEM;
>
> - ptime->start = 0;
> - ptime->end = 0;
> -
> - /* str has the format: <start>,<stop>
> - * variations: <start>,
> - * ,<stop>
> - * ,
> - */
> start_str = str;
> - d = strchr(start_str, ',');
> + d = strchr(start_str, ch);
> if (d) {
> *d = '\0';
> ++d;
> }
> end_str = d;
>
> + *start = start_str;
> + *end = end_str;
> +
> + return 0;
> +}
> +
> +int perf_time__parse_str(struct perf_time_interval *ptime, const char *ostr)
> +{
> + char *start_str = NULL, *end_str;
> + int rc;
> +
> + rc = split_start_end(&start_str, &end_str, ostr, ',');
> + if (rc || !start_str)
> + return rc;
> +
> + ptime->start = 0;
> + ptime->end = 0;
> +
> rc = parse_timestr_sec_nsec(ptime, start_str, end_str);
>
> - free(str);
> + free(start_str);
>
> /* make sure end time is after start time if it was given */
> if (rc == 0 && ptime->end && ptime->end < ptime->start)
> @@ -104,6 +114,177 @@ int perf_time__parse_str(struct perf_time_interval *ptime, const char *ostr)
> return rc;
> }
>
> +static int parse_percent(double *pcnt, char *str)
> +{
> + char *c;
> +
> + c = strchr(str, '%');
> + if (c)
> + *c = '\0';
> + else
> + return -1;
> +
> + *pcnt = atof(str) / 100.0;
> +
> + return 0;
> +}
> +
> +static int percent_slash_split(char *str, struct perf_time_interval *ptime,
> + u64 start, u64 end)
> +{
> + char *p, *end_str;
> + double pcnt, start_pcnt, end_pcnt;
> + u64 total = end - start;
> + int i;
> +
> + /*
> + * Example:
> + * 10%/2: select the second 10% slice and the third 10% slice
> + */
> +
> + /* We can modify this string since the original one is copied */
> + p = strchr(str, '/');
> + if (!p)
> + return -1;
> +
> + *p = '\0';
> + if (parse_percent(&pcnt, str) < 0)
> + return -1;
> +
> + p++;
> + i = (int)strtol(p, &end_str, 10);
> + if (*end_str)
> + return -1;
> +
> + if (pcnt <= 0.0)
> + return -1;
> +
> + start_pcnt = pcnt * (i - 1);
> + end_pcnt = pcnt * i;
> +
> + if (start_pcnt < 0.0 || start_pcnt > 1.0 ||
> + end_pcnt < 0.0 || end_pcnt > 1.0) {
> + return -1;
> + }
> +
> + ptime->start = start + round(start_pcnt * total);
> + ptime->end = start + round(end_pcnt * total);
> +
> + return 0;
> +}
> +
> +static int percent_dash_split(char *str, struct perf_time_interval *ptime,
> + u64 start, u64 end)
> +{
> + char *start_str = NULL, *end_str;
> + double start_pcnt, end_pcnt;
> + u64 total = end - start;
> + int ret;
> +
> + /*
> + * Example: 0%-10%
> + */
> +
> + ret = split_start_end(&start_str, &end_str, str, '-');
> + if (ret || !start_str)
> + return ret;
> +
> + if ((parse_percent(&start_pcnt, start_str) != 0) ||
> + (parse_percent(&end_pcnt, end_str) != 0)) {
> + free(start_str);
> + return -1;
> + }
> +
> + free(start_str);
> +
> + if (start_pcnt < 0.0 || start_pcnt > 1.0 ||
> + end_pcnt < 0.0 || end_pcnt > 1.0 ||
> + start_pcnt > end_pcnt) {
> + return -1;
> + }
> +
> + ptime->start = start + round(start_pcnt * total);
> + ptime->end = start + round(end_pcnt * total);
> +
> + return 0;
> +}
> +
> +typedef int (*time_pecent_split)(char *, struct perf_time_interval *,
> + u64 start, u64 end);
> +
> +static int percent_comma_split(struct perf_time_interval *ptime_buf, int num,
> + const char *ostr, u64 start, u64 end,
> + time_pecent_split func)
> +{
> + char *str, *p1, *p2;
> + int len, ret, i = 0;
> +
> + str = strdup(ostr);
> + if (str == NULL)
> + return -ENOMEM;
> +
> + len = strlen(str);
> + p1 = str;
> +
> + while (p1 < str + len) {
> + if (i >= num) {
> + free(str);
> + return -1;
> + }
> +
> + p2 = strchr(p1, ',');
> + if (p2)
> + *p2 = '\0';
> +
> + ret = (func)(p1, &ptime_buf[i], start, end);
> + if (ret < 0) {
> + free(str);
> + return -1;
> + }
> +
> + pr_debug("start time %d: %" PRIu64 ", ", i, ptime_buf[i].start);
> + pr_debug("end time %d: %" PRIu64 "\n", i, ptime_buf[i].end);
> +
> + i++;
> +
> + if (p2)
> + p1 = p2 + 1;
> + else
> + break;
> + }
> +
> + free(str);
> + return i;
> +}
> +
> +int perf_time__percent_parse_str(struct perf_time_interval *ptime_buf, int num,
> + const char *ostr, u64 start, u64 end)
> +{
> + char *c;
> +
> + /*
> + * ostr example:
> + * 10%/2,10%/3: select the second 10% slice and the third 10% slice
> + * 0%-10%,30%-40%: multiple time range
> + */
> +
> + memset(ptime_buf, 0, sizeof(*ptime_buf) * num);
> +
> + c = strchr(ostr, '/');
> + if (c) {
> + return percent_comma_split(ptime_buf, num, ostr, start,
> + end, percent_slash_split);
> + }
> +
> + c = strchr(ostr, '-');
> + if (c) {
> + return percent_comma_split(ptime_buf, num, ostr, start,
> + end, percent_dash_split);
> + }
> +
> + return -1;
> +}
> +
> bool perf_time__skip_sample(struct perf_time_interval *ptime, u64 timestamp)
> {
> /* if time is not set don't drop sample */
> diff --git a/tools/perf/util/time-utils.h b/tools/perf/util/time-utils.h
> index 15b475c..2308723 100644
> --- a/tools/perf/util/time-utils.h
> +++ b/tools/perf/util/time-utils.h
> @@ -13,6 +13,9 @@ int parse_nsec_time(const char *str, u64 *ptime);
>
> int perf_time__parse_str(struct perf_time_interval *ptime, const char *ostr);
>
> +int perf_time__percent_parse_str(struct perf_time_interval *ptime_buf, int num,
> + const char *ostr, u64 start, u64 end);
> +
> bool perf_time__skip_sample(struct perf_time_interval *ptime, u64 timestamp);
>
> int timestamp__scnprintf_usec(u64 timestamp, char *buf, size_t sz);
> --
> 2.7.4