[PATCH 2/4] tools/perf: Add new macros for mem_hops field

From: Kajol Jain
Date: Mon Dec 06 2021 - 04:19:45 EST


Add new macros for mem_hops field which can be used to
represent remote-node, socket and board level details.

Currently the code had macro for HOPS_0 which, corresponds
to data coming from another core but same node.
Add new macros for HOPS_1 to HOPS_3 to represent
remote-node, socket and board level data.

Also add corresponding strings in the mem_hops array to
represent mem_hop field data in perf_mem__lvl_scnprintf function

Incase mem_hops field is used, PERF_MEM_LVLNUM field also need
to be set inorder to represent the data source. Hence printing
data source via PERF_MEM_LVL field can be skip in that scenario.

For ex: Encodings for mem_hops fields with L2 cache:

L2 - local L2
L2 | REMOTE | HOPS_0 - remote core, same node L2
L2 | REMOTE | HOPS_1 - remote node, same socket L2
L2 | REMOTE | HOPS_2 - remote socket, same board L2
L2 | REMOTE | HOPS_3 - remote board L2

Signed-off-by: Kajol Jain <kjain@xxxxxxxxxxxxx>
---
tools/include/uapi/linux/perf_event.h | 5 ++++-
tools/perf/util/mem-events.c | 29 +++++++++++++++++----------
2 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h
index bd8860eeb291..4cd39aaccbe7 100644
--- a/tools/include/uapi/linux/perf_event.h
+++ b/tools/include/uapi/linux/perf_event.h
@@ -1332,7 +1332,10 @@ union perf_mem_data_src {

/* hop level */
#define PERF_MEM_HOPS_0 0x01 /* remote core, same node */
-/* 2-7 available */
+#define PERF_MEM_HOPS_1 0x02 /* remote node, same socket */
+#define PERF_MEM_HOPS_2 0x03 /* remote socket, same board */
+#define PERF_MEM_HOPS_3 0x04 /* remote board */
+/* 5-7 available */
#define PERF_MEM_HOPS_SHIFT 43

#define PERF_MEM_S(a, s) \
diff --git a/tools/perf/util/mem-events.c b/tools/perf/util/mem-events.c
index 3167b4628b6d..ed0ab838bcc5 100644
--- a/tools/perf/util/mem-events.c
+++ b/tools/perf/util/mem-events.c
@@ -309,6 +309,9 @@ static const char * const mem_hops[] = {
* to be set with mem_hops field.
*/
"core, same node",
+ "node, same socket",
+ "socket, same board",
+ "board",
};

int perf_mem__lvl_scnprintf(char *out, size_t sz, struct mem_info *mem_info)
@@ -316,7 +319,7 @@ int perf_mem__lvl_scnprintf(char *out, size_t sz, struct mem_info *mem_info)
size_t i, l = 0;
u64 m = PERF_MEM_LVL_NA;
u64 hit, miss;
- int printed;
+ int printed = 0;

if (mem_info)
m = mem_info->data_src.mem_lvl;
@@ -335,18 +338,22 @@ int perf_mem__lvl_scnprintf(char *out, size_t sz, struct mem_info *mem_info)
l += 7;
}

- if (mem_info && mem_info->data_src.mem_hops)
+ /*
+ * Incase mem_hops field is set, we can skip printing data source via
+ * PERF_MEM_LVL namespace.
+ */
+ if (mem_info && mem_info->data_src.mem_hops) {
l += scnprintf(out + l, sz - l, "%s ", mem_hops[mem_info->data_src.mem_hops]);
-
- printed = 0;
- for (i = 0; m && i < ARRAY_SIZE(mem_lvl); i++, m >>= 1) {
- if (!(m & 0x1))
- continue;
- if (printed++) {
- strcat(out, " or ");
- l += 4;
+ } else {
+ for (i = 0; m && i < ARRAY_SIZE(mem_lvl); i++, m >>= 1) {
+ if (!(m & 0x1))
+ continue;
+ if (printed++) {
+ strcat(out, " or ");
+ l += 4;
+ }
+ l += scnprintf(out + l, sz - l, mem_lvl[i]);
}
- l += scnprintf(out + l, sz - l, mem_lvl[i]);
}

if (mem_info && mem_info->data_src.mem_lvl_num) {
--
2.27.0