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util: Add support to calculate MBA utilization

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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>
This commit is contained in:
Bing Niu 2018-07-30 11:12:32 +08:00 committed by John Ferlan
parent 34a2ba2c46
commit f977ad89e0
1 changed files with 93 additions and 12 deletions
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105
src/util/virresctrl.c
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@ -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;