Refactor schemas and virresctrl to support optional <cache> element
in <cachetune>.
Later, the monitor entry will be introduced and to be placed
under <cachetune>. Either cache entry or monitor entry is
an optional element of <cachetune>.
An cachetune has no <cache> element is taking the default resource
allocating policy defined in '/sys/fs/resctrl/schemata'.
Signed-off-by: Wang Huaqiang <huaqiang.wang@xxxxxxxxx>
---
docs/formatdomain.html.in | 4 ++--
docs/schemas/domaincommon.rng | 4 ++--
src/util/virresctrl.c | 28 ++++++++++++++++++++++++++++
3 files changed, 32 insertions(+), 4 deletions(-)
diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index 8189959..b1651e3 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -943,8 +943,8 @@
<dl>
<dt><code>cache</code></dt>
<dd>
- This element controls the allocation of CPU cache and has the
- following attributes:
+ This optional element controls the allocation of CPU cache and has
+ the following attributes:
<dl>
<dt><code>level</code></dt>
<dd>
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index 099a949..5c533d6 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -956,7 +956,7 @@
<attribute name="vcpus">
<ref name='cpuset'/>
</attribute>
- <oneOrMore>
+ <zeroOrMore>
<element name="cache">
<attribute name="id">
<ref name='unsignedInt'/>
@@ -980,7 +980,7 @@
</attribute>
</optional>
</element>
- </oneOrMore>
+ </zeroOrMore>
</element>
</zeroOrMore>
<zeroOrMore>
diff --git a/src/util/virresctrl.c b/src/util/virresctrl.c
index 5d811a2..91bd341 100644
--- a/src/util/virresctrl.c
+++ b/src/util/virresctrl.c
@@ -234,6 +234,11 @@ virResctrlInfoMonFree(virResctrlInfoMonPtr mon)
* in case there is no allocation for that particular cache allocation (level,
* cache, ...) or memory allocation for particular node).
*
+ * Allocation corresponding to root directory, /sys/fs/sysctrl/, defines the
+ * default resource allocating policy, which is created immediately after
+ * mounting, and owns all the tasks and cpus in the system. Cache or memory
+ * bandwidth resource will be shared for tasks in this allocation.
+ *
* =====Cache allocation technology (CAT)=====
*
* Since one allocation can be made for caches on different levels, the first
@@ -2215,6 +2220,15 @@ virResctrlAllocDeterminePath(virResctrlAllocPtr alloc,
return -1;
}
+ /* If the allocation is empty, then the path will be SYSFS_RESCTRL_PATH */
+ if (virResctrlAllocIsEmpty(alloc)) {
+ if (!alloc->path &&
+ VIR_STRDUP(alloc->path, SYSFS_RESCTRL_PATH) < 0)
+ return -1;
+
+ return 0;
+ }
+
if (!alloc->path &&
virAsprintf(&alloc->path, "%s/%s-%s",
SYSFS_RESCTRL_PATH, machinename, alloc->id) < 0)
@@ -2248,6 +2262,11 @@ virResctrlAllocCreate(virResctrlInfoPtr resctrl,
if (virResctrlAllocDeterminePath(alloc, machinename) < 0)
return -1;
+ /* If the allocation is empty, then do not create directory in underlying
+ * resctrl file system */
+ if (virResctrlAllocIsEmpty(alloc))
+ return 0;
+
if (virFileExists(alloc->path)) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Path '%s' for resctrl allocation exists"),
@@ -2302,6 +2321,11 @@ virResctrlAllocAddPID(virResctrlAllocPtr alloc,
char *pidstr = NULL;
int ret = 0;
+ /* If the allocation is empty, then it is impossible to add a PID to
+ * allocation due to lacking of its 'tasks' file. Just return */
+ if (virResctrlAllocIsEmpty(alloc))
+ return 0;
+
if (!alloc->path) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Cannot add pid to non-existing resctrl allocation"));
@@ -2334,6 +2358,10 @@ virResctrlAllocRemove(virResctrlAllocPtr alloc)
{
int ret = 0;
+ /* No directory have ever been created. Just return */
+ if (virResctrlAllocIsEmpty(alloc))
+ return 0;
+
if (!alloc->path)
return 0;
--
2.7.4
--
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