hv_24x7 performance monitoring unit creates list of supported events
from the event catalog obtained via HCALL. hv_24x7 catalog could also
contain invalid or dummy events (with names like FREE_* or CPM_FREE_*
and RESERVED*). These events do not have any hardware counters
backing them. So patch adds a check to string compare the event names
to filter out them.
Result in power9 machine:
Before this patch:
.....
hv_24x7/PM_XLINK2_OUT_ODD_CYC,chip=?/ [Kernel PMU event]
hv_24x7/PM_XLINK2_OUT_ODD_DATA_COUNT,chip=?/ [Kernel PMU event]
hv_24x7/PM_XLINK2_OUT_ODD_TOTAL_UTIL,chip=?/ [Kernel PMU event]
hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT,chip=?/ [Kernel PMU event]
hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT_MISS,chip=?/ [Kernel PMU event]
hv_24x7/PM_XTS_ATSD_SENT,chip=?/ [Kernel PMU event]
hv_24x7/PM_XTS_ATSD_TLBI_RCV,chip=?/ [Kernel PMU event]
hv_24x7/RESERVED_NEST1,chip=?/ [Kernel PMU event]
hv_24x7/RESERVED_NEST10,chip=?/ [Kernel PMU event]
hv_24x7/RESERVED_NEST11,chip=?/ [Kernel PMU event]
hv_24x7/RESERVED_NEST12,chip=?/ [Kernel PMU event]
hv_24x7/RESERVED_NEST13,chip=?/ [Kernel PMU event]
......
Dmesg:
[ 0.000362] printk: console [hvc0] enabled
[ 0.815452] hv-24x7: read 1530 catalog entries, created 537 event attrs
(0 failures), 275 descs
After this patch:
......
hv_24x7/PM_XLINK2_OUT_ODD_AVLBL_CYC,chip=?/ [Kernel PMU event]
hv_24x7/PM_XLINK2_OUT_ODD_CYC,chip=?/ [Kernel PMU event]
hv_24x7/PM_XLINK2_OUT_ODD_DATA_COUNT,chip=?/ [Kernel PMU event]
hv_24x7/PM_XLINK2_OUT_ODD_TOTAL_UTIL,chip=?/ [Kernel PMU event]
hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT,chip=?/ [Kernel PMU event]
hv_24x7/PM_XTS_ATR_DEMAND_CHECKOUT_MISS,chip=?/ [Kernel PMU event]
hv_24x7/PM_XTS_ATSD_SENT,chip=?/ [Kernel PMU event]
hv_24x7/PM_XTS_ATSD_TLBI_RCV,chip=?/ [Kernel PMU event]
hv_24x7/TOD,chip=?/ [Kernel PMU event]
......
Demsg:
[ 0.000357] printk: console [hvc0] enabled
[ 0.808592] hv-24x7: read 1530 catalog entries, created 509 event attrs
(0 failures), 275 descs
Signed-off-by: Kajol Jain <kj...@linux.ibm.com>
---
arch/powerpc/perf/hv-24x7.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
---
Changelog
v1 -> v2
- Include "RESERVED*" as part of the invalid event check as
suggested by Madhavan Srinivasan
- Add new helper function "ignore_event" to check invalid/dummy
events as suggested by Michael Ellerman
- Remove pr_info to print each invalid event as suggested by
Michael Ellerman
---
diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c
index 6e7e820508df..1a6004d88f98 100644
--- a/arch/powerpc/perf/hv-24x7.c
+++ b/arch/powerpc/perf/hv-24x7.c
@@ -764,6 +764,16 @@ static ssize_t catalog_event_len_validate(struct
hv_24x7_event_data *event,
return ev_len;
}
+/*
+ * Return true incase of invalid or dummy events with names like FREE_* or
CPM_FREE_*
+ * and RESERVED*
+ */
+static bool ignore_event(const char *name)
+{
+ return (strstr(name, "FREE_") || !strncmp(name, "RESERVED", 8)) ?
+ true : false;
+}
+
#define MAX_4K (SIZE_MAX / 4096)
static int create_events_from_catalog(struct attribute ***events_,
@@ -894,6 +904,10 @@ static int create_events_from_catalog(struct attribute
***events_,
name = event_name(event, &nl);
+ if (ignore_event(name)) {
+ junk_events++;
+ continue;
+ }
if (event->event_group_record_len == 0) {
pr_devel("invalid event %zu (%.*s): group_record_len ==
0, skipping\n",
event_idx, nl, name);
@@ -955,6 +969,9 @@ static int create_events_from_catalog(struct attribute
***events_,
continue;
name = event_name(event, &nl);
+ if (ignore_event(name))
+ continue;
+
nonce = event_uniq_add(&ev_uniq, name, nl, event->domain);
ct = event_data_to_attrs(event_idx, events + event_attr_ct,
event, nonce);
--
2.27.0
