From e7c6fd7c476effdc12330c22ea716186310226ec Mon Sep 17 00:00:00 2001

Message-Id: <e7c6fd7c476effdc12330c22ea716186310226ec@dist-git>

From: Bing Niu <bing.niu@intel.com>

Date: Mon, 15 Apr 2019 17:32:51 +0200

Subject: [PATCH] util: Add support to calculate MBA utilization

MIME-Version: 1.0

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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@intel.com>

Reviewed-by: John Ferlan <jferlan@redhat.com>

(cherry picked from commit f977ad89e0202b5bcf5a90de45e19afb0159b458)

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1468650

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>

Message-Id: <5d177636966efd2f1132ad5a1a38b5bb2fad7e92.1555342313.git.phrdina@redhat.com>

Reviewed-by: Ján Tomko <jtomko@redhat.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 3148184d28..21a9247cb6 100644

--- a/src/util/virresctrl.c

+++ b/src/util/virresctrl.c

@@ -1408,6 +1408,22 @@ 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)

 {

@@ -1471,14 +1487,15 @@ 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)

@@ -1524,6 +1541,7 @@ virResctrlAllocGetUnused(virResctrlInfoPtr resctrl)

             goto error;

         }

+        virResctrlMemoryBandwidthSubtract(ret, alloc);

         virResctrlAllocSubtract(ret, alloc);

         virObjectUnref(alloc);

         alloc = NULL;

@@ -1674,6 +1692,66 @@ 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)

@@ -1713,10 +1791,10 @@ 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,

@@ -1735,6 +1813,9 @@ 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;

-- 

2.21.0