[PATCH 6/7] perf: Add support to dynamically get cacheline size

From: Don Zickus
Date: Tue May 27 2014 - 12:29:15 EST


Different arches may have different cacheline sizes. Look it up and set
a global variable for reference.

Signed-off-by: Don Zickus <dzickus@xxxxxxxxxx>

---
V2: change to be global and setup in perf.c
use filename__read_int for setup
---
tools/perf/perf.c | 5 +++++
tools/perf/util/cpumap.c | 27 +++++++++++++++++++++++++++
tools/perf/util/cpumap.h | 3 +++
tools/perf/util/sort.c | 1 +
tools/perf/util/util.c | 1 +
tools/perf/util/util.h | 1 +
6 files changed, 38 insertions(+)

diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 431798a..dabf08b 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -13,6 +13,7 @@
#include "util/quote.h"
#include "util/run-command.h"
#include "util/parse-events.h"
+#include "util/cpumap.h"
#include <api/fs/debugfs.h>
#include <pthread.h>

@@ -459,6 +460,10 @@ int main(int argc, const char **argv)
/* The page_size is placed in util object. */
page_size = sysconf(_SC_PAGE_SIZE);

+ /* The cacheline_size is placed in util objet */
+ if (cpu__setup_cacheline_size() < 0)
+ goto out;
+
cmd = perf_extract_argv0_path(argv[0]);
if (!cmd)
cmd = "perf-help";
diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
index c4e55b7..1029982 100644
--- a/tools/perf/util/cpumap.c
+++ b/tools/perf/util/cpumap.c
@@ -477,3 +477,30 @@ int cpu__setup_cpunode_map(void)
closedir(dir1);
return 0;
}
+
+int cpu__setup_cacheline_size(void)
+{
+ const char *mnt;
+ char path[PATH_MAX];
+ int n, size;
+
+
+ mnt = sysfs__mountpoint();
+ if (!mnt)
+ return -1;
+
+ n = snprintf(path, PATH_MAX, "%s/devices/system/cpu/cpu0/cache/index0/coherency_line_size", mnt);
+ if (n == PATH_MAX) {
+ pr_err("sysfs path crossed PATH_MAX(%d) size\n", PATH_MAX);
+ return -1;
+ }
+
+ if (filename__read_int(path, &size)) {
+ pr_err("Can not read cacheline size\n");
+ return -1;
+ }
+
+ cacheline_size = size;
+
+ return 0;
+}
diff --git a/tools/perf/util/cpumap.h b/tools/perf/util/cpumap.h
index 61a6548..507d7fd 100644
--- a/tools/perf/util/cpumap.h
+++ b/tools/perf/util/cpumap.h
@@ -5,6 +5,7 @@
#include <stdbool.h>

#include "perf.h"
+#include "util/util.h"
#include "util/debug.h"

struct cpu_map {
@@ -81,4 +82,6 @@ static inline int cpu__get_node(int cpu)
return cpunode_map[cpu];
}

+int cpu__setup_cacheline_size(void);
+
#endif /* __PERF_CPUMAP_H */
diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index 635cd8f..6e06567 100644
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -2,6 +2,7 @@
#include "hist.h"
#include "comm.h"
#include "symbol.h"
+#include "cpumap.h"

regex_t parent_regex;
const char default_parent_pattern[] = "^sys_|^do_page_fault";
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index 7fff6be..95aefa7 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -17,6 +17,7 @@
* XXX We need to find a better place for these things...
*/
unsigned int page_size;
+int cacheline_size;

bool test_attr__enabled;

diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index b03da44..6686436 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -304,6 +304,7 @@ char *rtrim(char *s);
void dump_stack(void);

extern unsigned int page_size;
+extern int cacheline_size;

void get_term_dimensions(struct winsize *ws);

--
1.7.11.7

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