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Subject[PATCH 6/7] perf: Add support to dynamically get cacheline size
Date
Different arches may have different cacheline sizes.  Look it up and set
a global variable for reference.

Signed-off-by: Don Zickus <dzickus@redhat.com>
---
tools/perf/util/cpumap.c | 31 +++++++++++++++++++++++++++++++
tools/perf/util/cpumap.h | 12 ++++++++++++
tools/perf/util/sort.c | 3 +++
3 files changed, 46 insertions(+)

diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
index c4e55b7..d833238 100644
--- a/tools/perf/util/cpumap.c
+++ b/tools/perf/util/cpumap.c
@@ -477,3 +477,34 @@ 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, ret, size;
+ FILE *fp;
+
+
+ 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;
+ }
+
+ fp = fopen(path, "r");
+ if (!fp)
+ return -1;
+ ret = fscanf(fp, "%d", &size);
+ fclose(fp);
+ if (ret != 1)
+ return -1;
+
+ cacheline_size = size;
+
+ return 0;
+}
diff --git a/tools/perf/util/cpumap.h b/tools/perf/util/cpumap.h
index 61a6548..b3e7b22 100644
--- a/tools/perf/util/cpumap.h
+++ b/tools/perf/util/cpumap.h
@@ -81,4 +81,16 @@ static inline int cpu__get_node(int cpu)
return cpunode_map[cpu];
}

+int cacheline_size;
+
+int cpu__setup_cacheline_size(void);
+
+static inline int cpu__cacheline_size(void)
+{
+ if (unlikely(!cacheline_size))
+ pr_debug("cacheline size not initialized\n");
+
+ return cacheline_size;
+}
+
#endif /* __PERF_CPUMAP_H */
diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index 635cd8f..50adbfb 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";
@@ -1117,6 +1118,8 @@ int setup_sorting(void)
return -ENOMEM;
}

+ cpu__setup_cacheline_size();
+
for (tok = strtok_r(str, ", ", &tmp);
tok; tok = strtok_r(NULL, ", ", &tmp)) {
ret = sort_dimension__add(tok);
--
1.7.11.7


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