10:12 p.m.
From: Bing Niu <bing.niu(a)intel.com>
Introduce virResctrlMemoryBandwidthSubtract and
virResctrlAllocMemoryBandwidth to be used as part of
the virResctrlAllocAssign processing to configure
the available memory bandwidth.
Signed-off-by: Bing Niu <bing.niu(a)intel.com>
---
src/util/virresctrl.c | 105 ++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 93 insertions(+), 12 deletions(-)
diff --git a/src/util/virresctrl.c b/src/util/virresctrl.c
index 1cbf9b3..c22b30f 100644
--- a/src/util/virresctrl.c
+++ b/src/util/virresctrl.c
@@ -1409,6 +1409,22 @@ virResctrlAllocSubtract(virResctrlAllocPtr dst,
}
+static void
+virResctrlMemoryBandwidthSubtract(virResctrlAllocPtr free,
+ virResctrlAllocPtr used)
+{
+ size_t i;
+
+ if (!used->mem_bw)
+ return;
+
+ for (i = 0; i < used->mem_bw->nbandwidths; i++) {
+ if (used->mem_bw->bandwidths[i])
+ *(free->mem_bw->bandwidths[i]) -=
*(used->mem_bw->bandwidths[i]);
+ }
+}
+
+
static virResctrlAllocPtr
virResctrlAllocNewFromInfo(virResctrlInfoPtr info)
{
@@ -1472,14 +1488,15 @@ virResctrlAllocNewFromInfo(virResctrlInfoPtr info)
}
/*
- * This function creates an allocation that represents all unused parts of all
- * caches in the system. It uses virResctrlInfo for creating a new full
- * allocation with all bits set (using virResctrlAllocNewFromInfo()) and then
- * scans for all allocations under /sys/fs/resctrl and subtracts each one of
- * them from it. That way it can then return an allocation with only bit set
- * being those that are not mentioned in any other allocation. It is used for
- * two things, a) calculating the masks when creating allocations and b) from
- * tests.
+ * This function creates an allocation that represents all unused parts of
+ * all caches and memory bandwidth in the system. It uses virResctrlInfo
+ * for creating a new full allocation with all bits set (using the
+ * virResctrlAllocNewFromInfo()), sets memory bandwidth 100%, and then scans
+ * for all allocations under /sys/fs/resctrl and subtracts each one of them
+ * from it. That way it can then return an allocation with only bit set
+ * being those that are not mentioned in any other allocation for CAT and
+ * available memory bandwidth for MBA. It is used for two things, calculating
+ * the masks and bandwidth available when creating allocations and from tests.
*/
virResctrlAllocPtr
virResctrlAllocGetUnused(virResctrlInfoPtr resctrl)
@@ -1525,6 +1542,7 @@ virResctrlAllocGetUnused(virResctrlInfoPtr resctrl)
goto error;
}
+ virResctrlMemoryBandwidthSubtract(ret, alloc);
virResctrlAllocSubtract(ret, alloc);
virObjectUnref(alloc);
alloc = NULL;
@@ -1676,6 +1694,66 @@ virResctrlAllocFindUnused(virResctrlAllocPtr alloc,
static int
+virResctrlAllocMemoryBandwidth(virResctrlInfoPtr resctrl,
+ virResctrlAllocPtr alloc,
+ virResctrlAllocPtr free)
+{
+ size_t i;
+ virResctrlAllocMemBWPtr mem_bw_alloc = alloc->mem_bw;
+ virResctrlAllocMemBWPtr mem_bw_free = free->mem_bw;
+ virResctrlInfoMemBWPtr mem_bw_info = resctrl->membw_info;
+
+ if (!mem_bw_alloc)
+ return 0;
+
+ if (mem_bw_alloc && !mem_bw_info) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+ _("RDT Memory Bandwidth allocation unsupported"));
+ return -1;
+ }
+
+ for (i = 0; i < mem_bw_alloc->nbandwidths; i++) {
+ if (!mem_bw_alloc->bandwidths[i])
+ continue;
+
+ if (*(mem_bw_alloc->bandwidths[i]) % mem_bw_info->bandwidth_granularity) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+ _("Memory Bandwidth allocation of size "
+ "%u is not divisible by granularity %u"),
+ *(mem_bw_alloc->bandwidths[i]),
+ mem_bw_info->bandwidth_granularity);
+ return -1;
+ }
+ if (*(mem_bw_alloc->bandwidths[i]) < mem_bw_info->min_bandwidth) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+ _("Memory Bandwidth allocation of size "
+ "%u is smaller than the minimum "
+ "allowed allocation %u"),
+ *(mem_bw_alloc->bandwidths[i]),
+ mem_bw_info->min_bandwidth);
+ return -1;
+ }
+ if (i > mem_bw_info->max_id) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+ _("bandwidth controller id %zd does not "
+ "exist, max controller id %u"),
+ i, mem_bw_info->max_id);
+ return -1;
+ }
+ if (*(mem_bw_alloc->bandwidths[i]) > *(mem_bw_free->bandwidths[i])) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+ _("Not enough room for allocation of %u%% "
+ "bandwidth on node %zd, available bandwidth
%u%%"),
+ *(mem_bw_alloc->bandwidths[i]), i,
+ *(mem_bw_free->bandwidths[i]));
+ return -1;
+ }
+ }
+ return 0;
+}
+
+
+static int
virResctrlAllocCopyMasks(virResctrlAllocPtr dst,
virResctrlAllocPtr src)
{
@@ -1714,10 +1792,10 @@ virResctrlAllocCopyMasks(virResctrlAllocPtr dst,
/*
- * This function is called when creating an allocation in the system. What it
- * does is that it gets all the unused bits using virResctrlAllocGetUnused() and
- * then tries to find a proper space for every requested allocation effectively
- * transforming `sizes` into `masks`.
+ * This function is called when creating an allocation in the system.
+ * What it does is that it gets all the unused resources using
+ * virResctrlAllocGetUnused and then tries to find a proper space for
+ * every requested allocation effectively transforming `sizes` into `masks`.
*/
static int
virResctrlAllocAssign(virResctrlInfoPtr resctrl,
@@ -1736,6 +1814,9 @@ virResctrlAllocAssign(virResctrlInfoPtr resctrl,
if (!alloc_default)
goto cleanup;
+ if (virResctrlAllocMemoryBandwidth(resctrl, alloc, alloc_free) < 0)
+ goto cleanup;
+
if (virResctrlAllocCopyMasks(alloc, alloc_default) < 0)
goto cleanup;
--
2.7.4