[PATCH 02/25] perf tools: Add possibility to specify mmap size

From: Jiri Olsa
Date: Sun Sep 01 2013 - 06:37:17 EST


Adding possibility to specify mmap size via -m/--mmap-pages
by appending unit size character (B/K/M/G) to the
number, like:
$ perf record -m 8K ls
$ perf record -m 2M ls

The size is rounded up appropriately to follow perf
mmap restrictions.

If no unit is specified the number provides pages as
of now, like:
$ perf record -m 8 ls

Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Corey Ashford <cjashfor@xxxxxxxxxxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
---
tools/perf/Documentation/perf-kvm.txt | 4 +++-
tools/perf/Documentation/perf-record.txt | 4 +++-
tools/perf/Documentation/perf-top.txt | 4 +++-
tools/perf/Documentation/perf-trace.txt | 4 +++-
tools/perf/util/evlist.c | 32 ++++++++++++++++++++++++++------
tools/perf/util/util.c | 25 +++++++++++++++++++++++++
tools/perf/util/util.h | 14 ++++++++++++++
7 files changed, 77 insertions(+), 10 deletions(-)

diff --git a/tools/perf/Documentation/perf-kvm.txt b/tools/perf/Documentation/perf-kvm.txt
index ac84db2..6a06cef 100644
--- a/tools/perf/Documentation/perf-kvm.txt
+++ b/tools/perf/Documentation/perf-kvm.txt
@@ -109,7 +109,9 @@ STAT LIVE OPTIONS

-m::
--mmap-pages=::
- Number of mmap data pages. Must be a power of two.
+ Number of mmap data pages (must be a power of two) or size
+ specification with appended unit character - B/K/M/G. The
+ size is rounded up to have nearest pages power of two value.

-a::
--all-cpus::
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index e297b74..400e9bb 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -87,7 +87,9 @@ OPTIONS

-m::
--mmap-pages=::
- Number of mmap data pages. Must be a power of two.
+ Number of mmap data pages (must be a power of two) or size
+ specification with appended unit character - B/K/M/G. The
+ size is rounded up to have nearest pages power of two value.

-g::
--call-graph::
diff --git a/tools/perf/Documentation/perf-top.txt b/tools/perf/Documentation/perf-top.txt
index 58d6598..19ab69e 100644
--- a/tools/perf/Documentation/perf-top.txt
+++ b/tools/perf/Documentation/perf-top.txt
@@ -68,7 +68,9 @@ Default is to monitor all CPUS.

-m <pages>::
--mmap-pages=<pages>::
- Number of mmapped data pages.
+ Number of mmap data pages (must be a power of two) or size
+ specification with appended unit character - B/K/M/G. The
+ size is rounded up to have nearest pages power of two value.

-p <pid>::
--pid=<pid>::
diff --git a/tools/perf/Documentation/perf-trace.txt b/tools/perf/Documentation/perf-trace.txt
index daccd2c..d390efa 100644
--- a/tools/perf/Documentation/perf-trace.txt
+++ b/tools/perf/Documentation/perf-trace.txt
@@ -59,7 +59,9 @@ OPTIONS

-m::
--mmap-pages=::
- Number of mmap data pages. Must be a power of two.
+ Number of mmap data pages (must be a power of two) or size
+ specification with appended unit character - B/K/M/G. The
+ size is rounded up to have nearest pages power of two value.

-C::
--cpu::
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 4780b9e..8ea933f 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -634,14 +634,33 @@ static size_t perf_evlist__mmap_size(unsigned long pages)
int perf_evlist__parse_mmap_pages(const struct option *opt, const char *str,
int unset __maybe_unused)
{
- unsigned int pages, *mmap_pages = opt->value;
+ unsigned int pages, val, *mmap_pages = opt->value;
size_t size;
- char *eptr;
+ static struct parse_tag tags[] = {
+ { .tag = 'B', .mult = 1 },
+ { .tag = 'K', .mult = 1 << 10 },
+ { .tag = 'M', .mult = 1 << 20 },
+ { .tag = 'G', .mult = 1 << 30 },
+ { .tag = 0 },
+ };

- pages = strtoul(str, &eptr, 10);
- if (*eptr != '\0') {
- pr_err("failed to parse --mmap_pages/-m value\n");
- return -1;
+ val = parse_tag_value(str, tags);
+ if (val != (unsigned int) -1) {
+ /* we got file size value */
+ pages = PERF_ALIGN(val, page_size) / page_size;
+ if (!is_power_of_2(pages)) {
+ pages = next_pow2(pages);
+ pr_info("rounding mmap pages size to %u (%u pages)\n",
+ pages * page_size, pages);
+ }
+ } else {
+ /* we got pages count value */
+ char *eptr;
+ pages = strtoul(str, &eptr, 10);
+ if (*eptr != '\0') {
+ pr_err("failed to parse --mmap_pages/-m value\n");
+ return -1;
+ }
}

size = perf_evlist__mmap_size(pages);
@@ -685,6 +704,7 @@ int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages,

evlist->overwrite = overwrite;
evlist->mmap_len = perf_evlist__mmap_size(pages);
+ pr_debug("mmap size %luB\n", evlist->mmap_len);
mask = evlist->mmap_len - page_size - 1;

list_for_each_entry(evsel, &evlist->entries, node) {
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index 6d17b18..141317e 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -361,3 +361,28 @@ int parse_nsec_time(const char *str, u64 *ptime)
*ptime = time_sec * NSEC_PER_SEC + time_nsec;
return 0;
}
+
+unsigned long parse_tag_value(const char *str, struct parse_tag *tags)
+{
+ struct parse_tag *i = tags;
+
+ while (i->tag) {
+ char *s;
+
+ s = strchr(str, i->tag);
+ if (s) {
+ unsigned long int value;
+ char *endptr;
+
+ value = strtoul(str, &endptr, 10);
+ if (s != endptr)
+ break;
+
+ value *= i->mult;
+ return value;
+ }
+ i++;
+ }
+
+ return (unsigned long) -1;
+}
diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index a535359..c29ecaa 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -270,6 +270,13 @@ bool is_power_of_2(unsigned long n)
return (n != 0 && ((n & (n - 1)) == 0));
}

+static inline unsigned next_pow2(unsigned x)
+{
+ if (!x)
+ return 1;
+ return 1ULL << (32 - __builtin_clz(x - 1));
+}
+
size_t hex_width(u64 v);
int hex2u64(const char *ptr, u64 *val);

@@ -281,4 +288,11 @@ void dump_stack(void);
extern unsigned int page_size;

void get_term_dimensions(struct winsize *ws);
+
+struct parse_tag {
+ char tag;
+ int mult;
+};
+
+unsigned long parse_tag_value(const char *str, struct parse_tag *tags);
#endif /* GIT_COMPAT_UTIL_H */
--
1.7.11.7

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