diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index 269741a690c6a0db8f795c4ba69bbcd18e6627e1..8850a71d94c00d081ebfb366763ebf2162ec7794 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -943,8 +943,8 @@
cache
-
- 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:
level
-
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index b9ac5df47906a563f32f45fddfa90d9d501e3f4e..2b465be01d07a8fe20e61573c16fc0d0a9453a5b 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -956,7 +956,7 @@
-
+
@@ -980,7 +980,7 @@
-
+
diff --git a/src/util/virresctrl.c b/src/util/virresctrl.c
index 5d811a23c8f269b0a348b76eb409d553db47f775..7d9c6974ef2b5d42b063f991b7a10cca30eba532 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 +2262,10 @@ virResctrlAllocCreate(virResctrlInfoPtr resctrl,
if (virResctrlAllocDeterminePath(alloc, machinename) < 0)
return -1;
+ /* If using the system/default path for the allocation, then we're done */
+ if (STREQ(alloc->path, SYSFS_RESCTRL_PATH))
+ return 0;
+
if (virFileExists(alloc->path)) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Path '%s' for resctrl allocation exists"),
@@ -2302,6 +2320,11 @@ 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 so just return */
+ if (virResctrlAllocIsEmpty(alloc))
+ return 0;
+
if (!alloc->path) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Cannot add pid to non-existing resctrl allocation"));
@@ -2337,6 +2360,10 @@ virResctrlAllocRemove(virResctrlAllocPtr alloc)
if (!alloc->path)
return 0;
+ /* Do not destroy if path is the system/default path for the allocation */
+ if (STREQ(alloc->path, SYSFS_RESCTRL_PATH))
+ return 0;
+
VIR_DEBUG("Removing resctrl allocation %s", alloc->path);
if (rmdir(alloc->path) != 0 && errno != ENOENT) {
ret = -errno;