From 6013f8d130b617ab0ff14075e225b4bb8836702e Mon Sep 17 00:00:00 2001

Message-Id: <6013f8d130b617ab0ff14075e225b4bb8836702e@dist-git>

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

Date: Mon, 15 Apr 2019 17:32:49 +0200

Subject: [PATCH] util: Add MBA allocation to virresctrl

MIME-Version: 1.0

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Add memory bandwidth allocation support to virresctrl class.

Introducing virResctrlAllocMemBW which is used for allocating memory

bandwidth. Following virResctrlAllocPerType, it also employs a

nested sparse array to indicate whether allocation is available for

particular last level cache.

Signed-off-by: Bing Niu <bing.niu@intel.com>

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

(cherry picked from commit 4c727dacbf1bd2a8c4797daf6192b81b85f872f1)

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

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

Message-Id: <6c5c1d7dfd4415699a0bf7a5461c99e915dfea1b.1555342313.git.phrdina@redhat.com>

Reviewed-by: Ján Tomko <jtomko@redhat.com>

---

 src/util/virresctrl.c | 63 ++++++++++++++++++++++++++++++++++++++++---

 1 file changed, 59 insertions(+), 4 deletions(-)

diff --git a/src/util/virresctrl.c b/src/util/virresctrl.c

index f454868f1e..8a25798f7d 100644

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

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

@@ -36,9 +36,9 @@ VIR_LOG_INIT("util.virresctrl")

 /* Resctrl is short for Resource Control.  It might be implemented for various

- * resources, but at the time of this writing this is only supported for cache

- * allocation technology (aka CAT).  Hence the reson for leaving 'Cache' out of

- * all the structure and function names for now (can be added later if needed.

+ * resources. Currently this supports cache allocation technology (aka CAT) and

+ * memory bandwidth allocation (aka MBA). More resources technologies may be

+ * added in the future.

  */

@@ -89,6 +89,9 @@ typedef virResctrlAllocPerType *virResctrlAllocPerTypePtr;

 typedef struct _virResctrlAllocPerLevel virResctrlAllocPerLevel;

 typedef virResctrlAllocPerLevel *virResctrlAllocPerLevelPtr;

+typedef struct _virResctrlAllocMemBW virResctrlAllocMemBW;

+typedef virResctrlAllocMemBW *virResctrlAllocMemBWPtr;

+

 /* Class definitions and initializations */

 static virClassPtr virResctrlInfoClass;

@@ -180,7 +183,10 @@ virResctrlInfoDispose(void *obj)

  * consequently a directory under /sys/fs/resctrl).  Since it can have multiple

  * parts of multiple caches allocated it is represented as bunch of nested

  * sparse arrays (by sparse I mean array of pointers so that each might be NULL

- * in case there is no allocation for that particular one (level, cache, ...)).

+ * in case there is no allocation for that particular cache allocation (level,

+ * cache, ...) or memory allocation for particular node).

+ *

+ * =====Cache allocation technology (CAT)=====

  *

  * Since one allocation can be made for caches on different levels, the first

  * nested sparse array is of types virResctrlAllocPerLevel.  For example if you

@@ -205,6 +211,17 @@ virResctrlInfoDispose(void *obj)

  * all of them.  While doing that we store the bitmask in a sparse array of

  * virBitmaps named `masks` indexed the same way as `sizes`.  The upper bounds

  * of the sparse arrays are stored in nmasks or nsizes, respectively.

+ + *

+ * =====Memory Bandwidth allocation technology (MBA)=====

+ *

+ * The memory bandwidth allocation support in virResctrlAlloc works in the

+ * same fashion as CAT. However, memory bandwidth controller doesn't have a

+ * hierarchy organization as cache, each node have one memory bandwidth

+ * controller to memory bandwidth distribution. The number of memory bandwidth

+ * controller is identical with number of last level cache. So MBA also employs

+ * a sparse array to represent whether a memory bandwidth allocation happens

+ * on corresponding node. The available memory controller number is collected

+ * in 'virResctrlInfo'.

  */

 struct _virResctrlAllocPerType {

     /* There could be bool saying whether this is set or not, but since everything

@@ -225,12 +242,24 @@ struct _virResctrlAllocPerLevel {

      * VIR_CACHE_TYPE_LAST number of items */

 };

+/*

+ * virResctrlAllocMemBW represents one memory bandwidth allocation.

+ * Since it can have several last level caches in a NUMA system, it is

+ * also represented as a nested sparse arrays as virRestrlAllocPerLevel.

+ */

+struct _virResctrlAllocMemBW {

+    unsigned int **bandwidths;

+    size_t nbandwidths;

+};

+

 struct _virResctrlAlloc {

     virObject parent;

     virResctrlAllocPerLevelPtr *levels;

     size_t nlevels;

+    virResctrlAllocMemBWPtr mem_bw;

+

     /* The identifier (any unique string for now) */

     char *id;

     /* libvirt-generated path in /sys/fs/resctrl for this particular

@@ -274,6 +303,13 @@ virResctrlAllocDispose(void *obj)

         VIR_FREE(level);

     }

+    if (alloc->mem_bw) {

+        virResctrlAllocMemBWPtr mem_bw = alloc->mem_bw;

+        for (i = 0; i < mem_bw->nbandwidths; i++)

+            VIR_FREE(mem_bw->bandwidths[i]);

+        VIR_FREE(alloc->mem_bw);

+    }

+

     VIR_FREE(alloc->id);

     VIR_FREE(alloc->path);

     VIR_FREE(alloc->levels);

@@ -692,6 +728,9 @@ virResctrlAllocIsEmpty(virResctrlAllocPtr alloc)

     if (!alloc)

         return true;

+    if (alloc->mem_bw)

+        return false;

+

     for (i = 0; i < alloc->nlevels; i++) {

         virResctrlAllocPerLevelPtr a_level = alloc->levels[i];

@@ -1266,6 +1305,22 @@ virResctrlAllocNewFromInfo(virResctrlInfoPtr info)

         }

     }

+    /* set default free memory bandwidth to 100%*/

+    if (info->membw_info) {

+        if (VIR_ALLOC(ret->mem_bw) < 0)

+            goto error;

+

+        if (VIR_EXPAND_N(ret->mem_bw->bandwidths, ret->mem_bw->nbandwidths,

+                         info->membw_info->max_id + 1) < 0)

+            goto error;

+

+        for (i = 0; i < ret->mem_bw->nbandwidths; i++) {

+            if (VIR_ALLOC(ret->mem_bw->bandwidths[i]) < 0)

+                goto error;

+            *(ret->mem_bw->bandwidths[i]) = 100;

+        }

+    }

+

  cleanup:

     virBitmapFree(mask);

     return ret;

-- 

2.21.0