[libvirt] [PATCH 1/7] perf: add cache_l1dra perf event support

Nitesh Konkar niteshkonkar.libvirt at gmail.com
Thu Jan 19 04:58:38 UTC 2017


This patch adds support and documentation for
a generalized hardware cache event named as
cache_l1dra perf event for measuring read accesses
on level 1 data cache

Signed-off-by: Nitesh Konkar <nitkon12 at linux.vnet.ibm.com>
---
 docs/formatdomain.html.in                   |  7 +++++++
 docs/news.xml                               |  4 ++--
 docs/schemas/domaincommon.rng               |  1 +
 include/libvirt/libvirt-domain.h            | 11 +++++++++++
 src/libvirt-domain.c                        |  3 +++
 src/qemu/qemu_driver.c                      |  1 +
 src/util/virperf.c                          |  8 +++++++-
 src/util/virperf.h                          |  1 +
 tests/genericxml2xmlindata/generic-perf.xml |  1 +
 tools/virsh.pod                             |  5 ++++-
 10 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index 3f7f875..20ef976 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -1937,6 +1937,7 @@
   <event name='stalled_cycles_frontend' enabled='no'/>
   <event name='stalled_cycles_backend' enabled='no'/>
   <event name='ref_cpu_cycles' enabled='no'/>
+  <event name='cache_l1dra' enabled='no'/>
 </perf>
 ...
 </pre>
@@ -2015,6 +2016,12 @@
          by applications running on the platform</td>
       <td><code>perf.ref_cpu_cycles</code></td>
     </tr>
+    <tr>
+      <td><code>cache_l1dra</code></td>
+      <td>the count of total read accesses for level 1 data cache by
+          applications running on the platform</td>
+      <td><code>perf.cache_l1dra</code></td>
+    </tr>
   </table>
 
     <h3><a name="elementsDevices">Devices</a></h3>
diff --git a/docs/news.xml b/docs/news.xml
index 26efa3e..b31d0a4 100644
--- a/docs/news.xml
+++ b/docs/news.xml
@@ -106,8 +106,8 @@
         <description>
           Add support to get the count of branch instructions
           executed, branch misses, bus cycles, stalled frontend
-          cpu cycles, stalled backend cpu cycles, and ref cpu
-          cycles by applications running on the platform.
+          cpu cycles, stalled backend cpu cycles, ref cpu cycles
+          and cache l1dra by applications running on the platform.
         </description>
       </change>
       <change>
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index 4d76315..a65ad13 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -433,6 +433,7 @@
               <value>stalled_cycles_frontend</value>
               <value>stalled_cycles_backend</value>
               <value>ref_cpu_cycles</value>
+              <value>cache_l1dra</value>
             </choice>
           </attribute>
           <attribute name="enabled">
diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-domain.h
index e303140..e2ba6ce 100644
--- a/include/libvirt/libvirt-domain.h
+++ b/include/libvirt/libvirt-domain.h
@@ -2188,6 +2188,17 @@ void virDomainStatsRecordListFree(virDomainStatsRecordPtr *stats);
  */
 # define VIR_PERF_PARAM_REF_CPU_CYCLES "ref_cpu_cycles"
 
+ /**
+ * VIR_PERF_PARAM_CACHE_L1DRA:
+ *
+ * Macro for typed parameter name that represents cache_l1dra
+ * perf event which can be used to measure the count of total
+ * read accesses for level 1 data cache by applications running
+ * on the platform. It corresponds to the "perf.cache_l1dra"
+ * field in the *Stats APIs.
+ */
+# define VIR_PERF_PARAM_CACHE_L1DRA "cache_l1dra"
+
 int virDomainGetPerfEvents(virDomainPtr dom,
                            virTypedParameterPtr *params,
                            int *nparams,
diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c
index 5b3e842..fa39069 100644
--- a/src/libvirt-domain.c
+++ b/src/libvirt-domain.c
@@ -11250,6 +11250,9 @@ virConnectGetDomainCapabilities(virConnectPtr conn,
  *                             CPU frequency scaling by applications running
  *                             as unsigned long long. It is produced by the
  *                             ref_cpu_cycles perf event.
+ *     "perf.cache_l1dra" - The count of total read accesses for level 1 data
+ *                          cache as unsigned long long. It is produced by
+ *                          cache_l1dra perf event.
  *
  * Note that entire stats groups or individual stat fields may be missing from
  * the output in case they are not supported by the given hypervisor, are not
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index d4422f3..7e2ea96 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -9877,6 +9877,7 @@ qemuDomainSetPerfEvents(virDomainPtr dom,
                                VIR_PERF_PARAM_STALLED_CYCLES_FRONTEND, VIR_TYPED_PARAM_BOOLEAN,
                                VIR_PERF_PARAM_STALLED_CYCLES_BACKEND, VIR_TYPED_PARAM_BOOLEAN,
                                VIR_PERF_PARAM_REF_CPU_CYCLES, VIR_TYPED_PARAM_BOOLEAN,
+                               VIR_PERF_PARAM_CACHE_L1DRA, VIR_TYPED_PARAM_BOOLEAN,
                                NULL) < 0)
         return -1;
 
diff --git a/src/util/virperf.c b/src/util/virperf.c
index f64692b..11e64df 100644
--- a/src/util/virperf.c
+++ b/src/util/virperf.c
@@ -43,7 +43,8 @@ VIR_ENUM_IMPL(virPerfEvent, VIR_PERF_EVENT_LAST,
               "cache_references", "cache_misses",
               "branch_instructions", "branch_misses",
               "bus_cycles", "stalled_cycles_frontend",
-              "stalled_cycles_backend", "ref_cpu_cycles");
+              "stalled_cycles_backend", "ref_cpu_cycles",
+              "cache_l1dra");
 
 struct virPerfEvent {
     int type;
@@ -112,6 +113,11 @@ static struct virPerfEventAttr attrs[] = {
      .attrConfig = 0,
 # endif
     },
+    {.type = VIR_PERF_EVENT_CACHE_L1DRA,
+     .attrType = PERF_TYPE_HW_CACHE,
+     .attrConfig = (PERF_COUNT_HW_CACHE_L1D) |
+                   (PERF_COUNT_HW_CACHE_OP_READ << 8) |
+                   (PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16)},
 };
 typedef struct virPerfEventAttr *virPerfEventAttrPtr;
 
diff --git a/src/util/virperf.h b/src/util/virperf.h
index 1f43c92..36ceb3a 100644
--- a/src/util/virperf.h
+++ b/src/util/virperf.h
@@ -47,6 +47,7 @@ typedef enum {
                                               the backend of the instruction
                                               processor pipeline */
     VIR_PERF_EVENT_REF_CPU_CYCLES,   /* Count of ref cpu cycles */
+    VIR_PERF_EVENT_CACHE_L1DRA, /* Count of read accesses for level 1 data cache */
 
     VIR_PERF_EVENT_LAST
 } virPerfEventType;
diff --git a/tests/genericxml2xmlindata/generic-perf.xml b/tests/genericxml2xmlindata/generic-perf.xml
index 437cd65..9b01aef 100644
--- a/tests/genericxml2xmlindata/generic-perf.xml
+++ b/tests/genericxml2xmlindata/generic-perf.xml
@@ -26,6 +26,7 @@
     <event name='stalled_cycles_frontend' enabled='yes'/>
     <event name='stalled_cycles_backend' enabled='yes'/>
     <event name='ref_cpu_cycles' enabled='yes'/>
+    <event name='cache_l1dra' enabled='yes'/>
   </perf>
   <devices>
   </devices>
diff --git a/tools/virsh.pod b/tools/virsh.pod
index 0e434c0..798c02e 100644
--- a/tools/virsh.pod
+++ b/tools/virsh.pod
@@ -945,7 +945,8 @@ I<--perf> returns the statistics of all enabled perf events:
 "perf.bus_cycles" - the count of bus cycles,
 "perf.stalled_cycles_frontend" - the count of stalled frontend cpu cycles,
 "perf.stalled_cycles_backend" - the count of stalled backend cpu cycles,
-"perf.ref_cpu_cycles" - the count of ref cpu cycles
+"perf.ref_cpu_cycles" - the count of ref cpu cycles,
+"perf.cache_l1dra" - the count of read accesses for level 1 data cache
 
 See the B<perf> command for more details about each event.
 
@@ -2310,6 +2311,8 @@ B<Valid perf event names>
   ref_cpu_cycles   -  Provides the count of total cpu cycles
                       not affected by CPU frequency scaling by
                       applications running on the platform.
+  cache_l1dra - Provides the count of total read accesses for level 1
+                data cache by applications running on the platform.
 
 B<Note>: The statistics can be retrieved using the B<domstats> command using
 the I<--perf> flag.
-- 
1.9.3




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