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Message-Id: <1479846052-8020-3-git-send-email-lcapitulino@redhat.com>
Date: Tue, 22 Nov 2016 15:20:52 -0500
From: Luiz Capitulino <lcapitulino@...hat.com>
To: rostedt@...dmis.org
Cc: linux-kernel@...r.kernel.org
Subject: [PATCH 2/2] trace-cmd record: add --cpu-list option
With --cpu-list you can do:
# trace-cmd record --cpu-list 1,4,10-15 [...]
Which is much more human friendly than -M.
Support for --cpu-list is implemented by dynamically
allocating a cpu_set_t object and setting the parsed
CPUs. Using the CPU_SET API allows for more robost
error detection.
Signed-off-by: Luiz Capitulino <lcapitulino@...hat.com>
---
Documentation/trace-cmd-record.1.txt | 4 +
trace-record.c | 208 +++++++++++++++++++++++++++++++++++
2 files changed, 212 insertions(+)
diff --git a/Documentation/trace-cmd-record.1.txt b/Documentation/trace-cmd-record.1.txt
index b80520e..d7e806a 100644
--- a/Documentation/trace-cmd-record.1.txt
+++ b/Documentation/trace-cmd-record.1.txt
@@ -304,6 +304,10 @@ OPTIONS
executed will not be changed. This is useful if you want to monitor the
output of the command being executed, but not see the output from trace-cmd.
+*--cpu-list list*::
+ List of CPUs to be traced. The "list" argument can be comma separated
+ (eg. 1,2,4,5), a range (eg. 1-10) or a mix of the two (eg. 1,2,10-15).
+
EXAMPLES
--------
diff --git a/trace-record.c b/trace-record.c
index 0f1f2c4..49d76db 100644
--- a/trace-record.c
+++ b/trace-record.c
@@ -23,6 +23,7 @@
#include <string.h>
#include <stdarg.h>
#include <getopt.h>
+#include <limits.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>
@@ -2080,6 +2081,208 @@ static void update_pid_event_filters(struct buffer_instance *instance)
update_event_filters(instance);
}
+struct cpuset {
+ int nr_cpus;
+ size_t size;
+ cpu_set_t *set;
+};
+
+static void set_cpu(int cpu, struct cpuset *set)
+{
+ if (cpu < 0 || cpu > set->nr_cpus - 1)
+ die("invalid cpu in range");
+ CPU_SET_S(cpu, set->size, set->set);
+}
+
+static int read_cpu_nr(const char *str, int *ret)
+{
+ char *endptr;
+ int val;
+
+ errno = 0;
+ val = strtol(str, &endptr, 10);
+
+ if ((errno == ERANGE && (val == LONG_MAX || val == LONG_MIN))
+ || (errno != 0 && val == 0))
+ return -1;
+
+ if (endptr == str)
+ return -1;
+
+ if (*endptr != '\0')
+ return -1;
+
+ *ret = val;
+ return 0;
+}
+
+static int parse_single_cpu(const char *str, struct cpuset *set)
+{
+ int cpu, err;
+
+ err = read_cpu_nr(str, &cpu);
+ if (err)
+ return -1;
+
+ set_cpu(cpu, set);
+ return 0;
+}
+
+static int parse_range_one(char *str, char **saveptr)
+{
+ int err, cpu;
+ char *p;
+
+ p = strtok_r(str, "-", saveptr);
+ if (!p)
+ return -1;
+
+ err = read_cpu_nr(p, &cpu);
+ if (err)
+ return -1;
+
+ return cpu;
+}
+
+static int parse_range(const char *str, int *begin, int *end)
+{
+ char *saveptr, *range;
+ int ret;
+
+ range = strdup(str);
+ if (!range)
+ return -1;
+
+ ret = parse_range_one(range, &saveptr);
+ if (ret < 0)
+ goto out;
+ *begin = ret;
+
+ ret = parse_range_one(NULL, &saveptr);
+ if (ret < 0)
+ goto out;
+ *end = ret;
+
+out:
+ free(range);
+ return ret < 0 ? -1 : 0;
+}
+
+static int parse_cpu_range(const char *str, struct cpuset *set)
+{
+ int i, ret, begin, end;
+
+ ret = parse_range(str, &begin, &end);
+ if (ret < 0 || begin > end)
+ return -1;
+
+ for (i = begin; i <= end; i++)
+ set_cpu(i, set);
+
+ return 0;
+}
+
+static int has_range(const char *str)
+{
+ return strchr(str, '-') != NULL;
+}
+
+static int parse_cpu_list(const char *cpu_list, struct cpuset *set)
+{
+ char *saveptr, *str, *p;
+ int err = 0;
+
+ str = strdup(cpu_list);
+ if (!str)
+ return -1;
+
+ p = strtok_r(str, ",", &saveptr);
+ while (p) {
+ if (has_range(p))
+ err = parse_cpu_range(p, set);
+ else
+ err = parse_single_cpu(p, set);
+ if (err)
+ goto out;
+ p = strtok_r(NULL, ",", &saveptr);
+ }
+
+out:
+ free(str);
+ return err;
+}
+
+static int val_to_char(int v)
+{
+ if (v >= 0 && v < 10)
+ return '0' + v;
+ else if (v >= 10 && v < 16)
+ return ('a' - 10) + v;
+ else
+ return -1;
+}
+
+/* From util-linux */
+static char *cpu_set_to_str(char *str, size_t len, struct cpuset *set)
+{
+ char *ptr = str;
+ char *ret = NULL;
+ int cpu;
+
+ for (cpu = (8 * set->size) - 4; cpu >= 0; cpu -= 4) {
+ char val = 0;
+
+ if (len == (size_t) (ptr - str))
+ break;
+
+ if (CPU_ISSET_S(cpu, set->size, set->set))
+ val |= 1;
+ if (CPU_ISSET_S(cpu + 1, set->size, set->set))
+ val |= 2;
+ if (CPU_ISSET_S(cpu + 2, set->size, set->set))
+ val |= 4;
+ if (CPU_ISSET_S(cpu + 3, set->size, set->set))
+ val |= 8;
+
+ if (!ret && val)
+ ret = ptr;
+ *ptr++ = val_to_char(val);
+ }
+
+ *ptr = '\0';
+ return ret ? ret : ptr - 1;
+}
+
+static char *alloc_mask_from_list(const char *cpu_list)
+{
+ struct cpuset set;
+ char *str;
+ int ret;
+
+ set.nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
+ if (set.nr_cpus < 0)
+ die("can't get number of processors\n");
+
+ set.set = CPU_ALLOC(set.nr_cpus);
+ if (!set.set)
+ die("can't allocate cpu_set\n");
+
+ set.size = CPU_ALLOC_SIZE(set.nr_cpus);
+ CPU_ZERO_S(set.size, set.set);
+
+ ret = parse_cpu_list(cpu_list, &set);
+ if (ret < 0)
+ die("invalid cpu list specified");
+
+ str = malloc(CPUMASK_STR_MAX);
+ if (!str)
+ die("can't allocate memory\n");
+
+ cpu_set_to_str(str, CPUMASK_STR_MAX, &set);
+ CPU_FREE(set.set);
+
+ return str;
+}
static char *alloc_mask_from_hex(const char *str)
{
@@ -4137,6 +4340,7 @@ enum {
OPT_nosplice = 253,
OPT_funcstack = 254,
OPT_date = 255,
+ OPT_cpulist = 256,
};
void trace_record (int argc, char **argv)
@@ -4338,6 +4542,7 @@ void trace_record (int argc, char **argv)
{"stderr", no_argument, NULL, OPT_stderr},
{"by-comm", no_argument, NULL, OPT_bycomm},
{"ts-offset", required_argument, NULL, OPT_tsoffset},
+ {"cpu-list", required_argument, NULL, OPT_cpulist},
{"max-graph-depth", required_argument, NULL, OPT_max_graph_depth},
{"debug", no_argument, NULL, OPT_debug},
{"help", no_argument, NULL, '?'},
@@ -4546,6 +4751,9 @@ void trace_record (int argc, char **argv)
case 'M':
instance->cpumask = alloc_mask_from_hex(optarg);
break;
+ case OPT_cpulist:
+ instance->cpumask = alloc_mask_from_list(optarg);
+ break;
case 't':
if (extract)
topt = 1; /* Extract top instance also */
--
2.5.5
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