7 p.m.
This does two simplifications to the perf events code.
Daniel P. Berrange (2):
perf: get rid of pointless virPerfGetEventAttr() method
perf: get rid of pointless virPerfGetEvent() method
src/util/virperf.c | 162 +++++++++++++++++++++--------------------------------
1 file changed, 65 insertions(+), 97 deletions(-)
--
2.9.3
7 p.m.
New subject: [libvirt] [PATCH 1/2] perf: get rid of pointless virPerfGetEventAttr() method
The virPerfGetEventAttr method contains a totally pointless
loop. Remove it, verify the array size statically, and then
just use an array index to access the perf event.
Signed-off-by: Daniel P. Berrange <berrange(a)redhat.com>
---
src/util/virperf.c | 120 ++++++++++++++++++++++++++---------------------------
1 file changed, 58 insertions(+), 62 deletions(-)
diff --git a/src/util/virperf.c b/src/util/virperf.c
index f64692b..c8279c9 100644
--- a/src/util/virperf.c
+++ b/src/util/virperf.c
@@ -67,75 +67,73 @@ struct virPerf {
# include <linux/perf_event.h>
struct virPerfEventAttr {
- int type;
unsigned int attrType;
unsigned long long attrConfig;
};
static struct virPerfEventAttr attrs[] = {
- {.type = VIR_PERF_EVENT_CMT, .attrType = 0, .attrConfig = 1},
- {.type = VIR_PERF_EVENT_MBMT, .attrType = 0, .attrConfig = 2},
- {.type = VIR_PERF_EVENT_MBML, .attrType = 0, .attrConfig = 3},
- {.type = VIR_PERF_EVENT_CPU_CYCLES,
- .attrType = PERF_TYPE_HARDWARE,
- .attrConfig = PERF_COUNT_HW_CPU_CYCLES},
- {.type = VIR_PERF_EVENT_INSTRUCTIONS,
- .attrType = PERF_TYPE_HARDWARE,
- .attrConfig = PERF_COUNT_HW_INSTRUCTIONS},
- {.type = VIR_PERF_EVENT_CACHE_REFERENCES,
- .attrType = PERF_TYPE_HARDWARE,
- .attrConfig = PERF_COUNT_HW_CACHE_REFERENCES},
- {.type = VIR_PERF_EVENT_CACHE_MISSES,
- .attrType = PERF_TYPE_HARDWARE,
- .attrConfig = PERF_COUNT_HW_CACHE_MISSES},
- {.type = VIR_PERF_EVENT_BRANCH_INSTRUCTIONS,
- .attrType = PERF_TYPE_HARDWARE,
- .attrConfig = PERF_COUNT_HW_BRANCH_INSTRUCTIONS},
- {.type = VIR_PERF_EVENT_BRANCH_MISSES,
- .attrType = PERF_TYPE_HARDWARE,
- .attrConfig = PERF_COUNT_HW_BRANCH_MISSES},
- {.type = VIR_PERF_EVENT_BUS_CYCLES,
- .attrType = PERF_TYPE_HARDWARE,
- .attrConfig = PERF_COUNT_HW_BUS_CYCLES},
- {.type = VIR_PERF_EVENT_STALLED_CYCLES_FRONTEND,
- .attrType = PERF_TYPE_HARDWARE,
- .attrConfig = PERF_COUNT_HW_STALLED_CYCLES_FRONTEND},
- {.type = VIR_PERF_EVENT_STALLED_CYCLES_BACKEND,
- .attrType = PERF_TYPE_HARDWARE,
- .attrConfig = PERF_COUNT_HW_STALLED_CYCLES_BACKEND},
- {.type = VIR_PERF_EVENT_REF_CPU_CYCLES,
+ [VIR_PERF_EVENT_CMT] = {
+ .attrType = 0,
+ .attrConfig = 1
+ },
+ [VIR_PERF_EVENT_MBMT] = {
+ .attrType = 0,
+ .attrConfig = 2
+ },
+ [VIR_PERF_EVENT_MBML] {
+ .attrType = 0,
+ .attrConfig = 3
+ },
+ [VIR_PERF_EVENT_CPU_CYCLES] = {
+ .attrType = PERF_TYPE_HARDWARE,
+ .attrConfig = PERF_COUNT_HW_CPU_CYCLES
+ },
+ [VIR_PERF_EVENT_INSTRUCTIONS] = {
+ .attrType = PERF_TYPE_HARDWARE,
+ .attrConfig = PERF_COUNT_HW_INSTRUCTIONS
+ },
+ [VIR_PERF_EVENT_CACHE_REFERENCES] = {
+ .attrType = PERF_TYPE_HARDWARE,
+ .attrConfig = PERF_COUNT_HW_CACHE_REFERENCES
+ },
+ [VIR_PERF_EVENT_CACHE_MISSES] = {
+ .attrType = PERF_TYPE_HARDWARE,
+ .attrConfig = PERF_COUNT_HW_CACHE_MISSES
+ },
+ [VIR_PERF_EVENT_BRANCH_INSTRUCTIONS] = {
+ .attrType = PERF_TYPE_HARDWARE,
+ .attrConfig = PERF_COUNT_HW_BRANCH_INSTRUCTIONS
+ },
+ [VIR_PERF_EVENT_BRANCH_MISSES] = {
+ .attrType = PERF_TYPE_HARDWARE,
+ .attrConfig = PERF_COUNT_HW_BRANCH_MISSES
+ },
+ [VIR_PERF_EVENT_BUS_CYCLES] = {
+ .attrType = PERF_TYPE_HARDWARE,
+ .attrConfig = PERF_COUNT_HW_BUS_CYCLES
+ },
+ [VIR_PERF_EVENT_STALLED_CYCLES_FRONTEND] = {
+ .attrType = PERF_TYPE_HARDWARE,
+ .attrConfig = PERF_COUNT_HW_STALLED_CYCLES_FRONTEND
+ },
+ [VIR_PERF_EVENT_STALLED_CYCLES_BACKEND] = {
+ .attrType = PERF_TYPE_HARDWARE,
+ .attrConfig = PERF_COUNT_HW_STALLED_CYCLES_BACKEND
+ },
+ [VIR_PERF_EVENT_REF_CPU_CYCLES] = {
# ifdef PERF_COUNT_HW_REF_CPU_CYCLES
- .attrType = PERF_TYPE_HARDWARE,
- .attrConfig = PERF_COUNT_HW_REF_CPU_CYCLES
+ .attrType = PERF_TYPE_HARDWARE,
+ .attrConfig = PERF_COUNT_HW_REF_CPU_CYCLES
# else
- .attrType = 0,
- .attrConfig = 0,
+ .attrType = 0,
+ .attrConfig = 0,
# endif
},
};
+verify(ARRAY_CARDINALITY(attrs) == VIR_PERF_EVENT_LAST);
typedef struct virPerfEventAttr *virPerfEventAttrPtr;
-static virPerfEventAttrPtr
-virPerfGetEventAttr(virPerfEventType type)
-{
- size_t i;
- if (type >= VIR_PERF_EVENT_LAST) {
- virReportError(VIR_ERR_INTERNAL_ERROR,
- _("Event '%d' is not supported"),
- type);
- return NULL;
- }
-
- for (i = 0; i < VIR_PERF_EVENT_LAST; i++) {
- if (i == type)
- return attrs + i;
- }
-
- return NULL;
-}
-
-
static int
virPerfRdtAttrInit(void)
{
@@ -193,17 +191,15 @@ virPerfEventEnable(virPerfPtr perf,
char *buf = NULL;
struct perf_event_attr attr;
virPerfEventPtr event = virPerfGetEvent(perf, type);
- virPerfEventAttrPtr event_attr = virPerfGetEventAttr(type);
+ virPerfEventAttrPtr event_attr = &attrs[type];
- if (!event || !event_attr)
+ if (!event)
return -1;
- if (event_attr->attrType == 0 && (type == VIR_PERF_EVENT_CMT ||
- type == VIR_PERF_EVENT_MBMT ||
- type == VIR_PERF_EVENT_MBML)) {
+ if (event_attr->attrType == 0) {
virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED,
_("unable to enable host cpu perf event for %s"),
- virPerfEventTypeToString(event->type));
+ virPerfEventTypeToString(type));
return -1;
}
--
2.9.3
7 p.m.
New subject: [libvirt] [PATCH 2/2] perf: get rid of pointless virPerfGetEvent() method
The virPerfGetEvent method pointlessly checks for a NULL
parameter and the range of an enum value. The whole point
of using an enum is that we can avoid such checks. Just
replace calls to virPerfGetEvent, with perf->events[type]
array access.
Signed-off-by: Daniel P. Berrange <berrange(a)redhat.com>
---
src/util/virperf.c | 44 ++++++++------------------------------------
1 file changed, 8 insertions(+), 36 deletions(-)
diff --git a/src/util/virperf.c b/src/util/virperf.c
index c8279c9..edb9f54 100644
--- a/src/util/virperf.c
+++ b/src/util/virperf.c
@@ -46,7 +46,6 @@ VIR_ENUM_IMPL(virPerfEvent, VIR_PERF_EVENT_LAST,
"stalled_cycles_backend", "ref_cpu_cycles");
struct virPerfEvent {
- int type;
int fd;
bool enabled;
union {
@@ -166,23 +165,6 @@ virPerfRdtAttrInit(void)
}
-static virPerfEventPtr
-virPerfGetEvent(virPerfPtr perf,
- virPerfEventType type)
-{
- if (!perf)
- return NULL;
-
- if (type >= VIR_PERF_EVENT_LAST) {
- virReportError(VIR_ERR_INTERNAL_ERROR,
- _("Event '%d' is not supported"),
- type);
- return NULL;
- }
-
- return perf->events + type;
-}
-
int
virPerfEventEnable(virPerfPtr perf,
virPerfEventType type,
@@ -190,12 +172,9 @@ virPerfEventEnable(virPerfPtr perf,
{
char *buf = NULL;
struct perf_event_attr attr;
- virPerfEventPtr event = virPerfGetEvent(perf, type);
+ virPerfEventPtr event = &(perf->events[type]);
virPerfEventAttrPtr event_attr = &attrs[type];
- if (!event)
- return -1;
-
if (event_attr->attrType == 0) {
virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED,
_("unable to enable host cpu perf event for %s"),
@@ -229,14 +208,14 @@ virPerfEventEnable(virPerfPtr perf,
if (event->fd < 0) {
virReportSystemError(errno,
_("unable to open host cpu perf event for %s"),
- virPerfEventTypeToString(event->type));
+ virPerfEventTypeToString(type));
goto error;
}
if (ioctl(event->fd, PERF_EVENT_IOC_ENABLE) < 0) {
virReportSystemError(errno,
_("unable to enable host cpu perf event for %s"),
- virPerfEventTypeToString(event->type));
+ virPerfEventTypeToString(type));
goto error;
}
@@ -253,9 +232,7 @@ int
virPerfEventDisable(virPerfPtr perf,
virPerfEventType type)
{
- virPerfEventPtr event = virPerfGetEvent(perf, type);
- if (event == NULL)
- return -1;
+ virPerfEventPtr event = &(perf->events[type]);
if (!event->enabled)
return 0;
@@ -263,7 +240,7 @@ virPerfEventDisable(virPerfPtr perf,
if (ioctl(event->fd, PERF_EVENT_IOC_DISABLE) < 0) {
virReportSystemError(errno,
_("unable to disable host cpu perf event for
%s"),
- virPerfEventTypeToString(event->type));
+ virPerfEventTypeToString(type));
return -1;
}
@@ -275,11 +252,7 @@ virPerfEventDisable(virPerfPtr perf,
bool virPerfEventIsEnabled(virPerfPtr perf,
virPerfEventType type)
{
- virPerfEventPtr event = virPerfGetEvent(perf, type);
- if (event == NULL)
- return false;
-
- return event->enabled;
+ return perf->events[type].enabled;
}
int
@@ -287,8 +260,8 @@ virPerfReadEvent(virPerfPtr perf,
virPerfEventType type,
uint64_t *value)
{
- virPerfEventPtr event = virPerfGetEvent(perf, type);
- if (event == NULL || !event->enabled)
+ virPerfEventPtr event = &perf->events[type];
+ if (!event->enabled)
return -1;
if (saferead(event->fd, value, sizeof(uint64_t)) < 0) {
@@ -359,7 +332,6 @@ virPerfNew(void)
return NULL;
for (i = 0; i < VIR_PERF_EVENT_LAST; i++) {
- perf->events[i].type = i;
perf->events[i].fd = -1;
perf->events[i].enabled = false;
}
--
2.9.3
8:43 p.m.
On Fri, Dec 16, 2016 at 11:00:37AM +0000, Daniel P. Berrange wrote:
This does two simplifications to the perf events code.
Daniel P. Berrange (2):
perf: get rid of pointless virPerfGetEventAttr() method
perf: get rid of pointless virPerfGetEvent() method
src/util/virperf.c | 162 +++++++++++++++++++++--------------------------------
1 file changed, 65 insertions(+), 97 deletions(-)
ACK series.
Erik
--
2.9.3
--
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Erik Skultety