From e7c6fd7c476effdc12330c22ea716186310226ec Mon Sep 17 00:00:00 2001 Message-Id: From: Bing Niu Date: Mon, 15 Apr 2019 17:32:51 +0200 Subject: [PATCH] util: Add support to calculate MBA utilization MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Introduce virResctrlMemoryBandwidthSubtract and virResctrlAllocMemoryBandwidth to be used as part of the virResctrlAllocAssign processing to configure the available memory bandwidth. Signed-off-by: Bing Niu Reviewed-by: John Ferlan (cherry picked from commit f977ad89e0202b5bcf5a90de45e19afb0159b458) Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1468650 Signed-off-by: Pavel Hrdina Message-Id: <5d177636966efd2f1132ad5a1a38b5bb2fad7e92.1555342313.git.phrdina@redhat.com> Reviewed-by: Ján Tomko --- 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