[PATCH v2 5/6] perf kmem: Add option to specify time window of interest

[David Ahern]

Add option to allow user to control analysis window. e.g., collect data
for time window and analyze a segment of interest within that window.

Signed-off-by: David Ahern <dsah...@gmail.com>
---
 tools/perf/Documentation/perf-kmem.txt |  7 +++++++
 tools/perf/builtin-kmem.c              | 24 ++++++++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/tools/perf/Documentation/perf-kmem.txt 
b/tools/perf/Documentation/perf-kmem.txt
index ff0f433b3fce..479fc3261a50 100644
--- a/tools/perf/Documentation/perf-kmem.txt
+++ b/tools/perf/Documentation/perf-kmem.txt
@@ -61,6 +61,13 @@ OPTIONS
        default, but this option shows live (currently allocated) pages
        instead.  (This option works with --page option only)
 
+--time::
+       Only analyze samples within given time window: <start>,<stop>. Times
+       have the format seconds.microseconds. If start is not given (i.e., time
+       string is ',x.y') then analysis starts at the beginning of the file. If
+       stop time is not given (i.e, time string is 'x.y,') then analysis goes
+       to end of file.
+
 SEE ALSO
 --------
 linkperf:perf-record[1]
diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c
index 7fd6f1e1e293..35a02f8e5a4a 100644
--- a/tools/perf/builtin-kmem.c
+++ b/tools/perf/builtin-kmem.c
@@ -11,6 +11,7 @@
 #include "util/session.h"
 #include "util/tool.h"
 #include "util/callchain.h"
+#include "util/time-utils.h"
 
 #include <subcmd/parse-options.h>
 #include "util/trace-event.h"
@@ -66,6 +67,10 @@ static struct rb_root root_caller_sorted;
 static unsigned long total_requested, total_allocated, total_freed;
 static unsigned long nr_allocs, nr_cross_allocs;
 
+/* filters for controlling start and stop of time of analysis */
+static struct perf_time_interval ptime;
+const char *time_str;
+
 static int insert_alloc_stat(unsigned long call_site, unsigned long ptr,
                             int bytes_req, int bytes_alloc, int cpu)
 {
@@ -912,6 +917,15 @@ static int perf_evsel__process_page_free_event(struct 
perf_evsel *evsel,
        return 0;
 }
 
+static bool perf_kmem__skip_sample(struct perf_sample *sample)
+{
+       /* skip sample based on time? */
+       if (perf_time__skip_sample(&ptime, sample->time))
+               return true;
+
+       return false;
+}
+
 typedef int (*tracepoint_handler)(struct perf_evsel *evsel,
                                  struct perf_sample *sample);
 
@@ -931,6 +945,9 @@ static int process_sample_event(struct perf_tool *tool 
__maybe_unused,
                return -1;
        }
 
+       if (perf_kmem__skip_sample(sample))
+               return 0;
+
        dump_printf(" ... thread: %s:%d\n", thread__comm_str(thread), 
thread->tid);
 
        if (evsel->handler != NULL) {
@@ -1894,6 +1911,8 @@ int cmd_kmem(int argc, const char **argv, const char 
*prefix __maybe_unused)
        OPT_CALLBACK_NOOPT(0, "page", NULL, NULL, "Analyze page allocator",
                           parse_page_opt),
        OPT_BOOLEAN(0, "live", &live_page, "Show live page stat"),
+       OPT_STRING(0, "time", &time_str, "str",
+                  "Time span of interest (start,stop)"),
        OPT_END()
        };
        const char *const kmem_subcommands[] = { "record", "stat", NULL };
@@ -1954,6 +1973,11 @@ int cmd_kmem(int argc, const char **argv, const char 
*prefix __maybe_unused)
 
        symbol__init(&session->header.env);
 
+       if (perf_time__parse_str(&ptime, time_str) != 0) {
+               pr_err("Invalid time string\n");
+               return -EINVAL;
+       }
+
        if (!strcmp(argv[0], "stat")) {
                setlocale(LC_ALL, "");
 
-- 
2.7.4 (Apple Git-66)