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| author | Bibo Mao <maobibo@loongson.cn> | 2024-07-09 16:25:51 +0800 |
|---|---|---|
| committer | Huacai Chen <chenhuacai@loongson.cn> | 2024-07-09 16:25:51 +0800 |
| commit | 03779999ac3053122c33173a652100c8fa6c61c5 (patch) | |
| tree | 0da3fff59c30171c9d34464712bd4fae65e943e7 /arch/loongarch/Kconfig | |
| parent | b4ba157044ea433a66126603ad7140e12dbc794b (diff) | |
LoongArch: KVM: Add PV steal time support in guest side
Per-cpu struct kvm_steal_time is added here, its size is 64 bytes and
also defined as 64 bytes, so that the whole structure is in one physical
page.
When a VCPU is online, function pv_enable_steal_time() is called. This
function will pass guest physical address of struct kvm_steal_time and
tells hypervisor to enable steal time. When a vcpu is offline, physical
address is set as 0 and tells hypervisor to disable steal time.
Here is an output of vmstat on guest when there is workload on both host
and guest. It shows steal time stat information.
procs -----------memory---------- -----io---- -system-- ------cpu-----
r b swpd free inact active bi bo in cs us sy id wa st
15 1 0 7583616 184112 72208 20 0 162 52 31 6 43 0 20
17 0 0 7583616 184704 72192 0 0 6318 6885 5 60 8 5 22
16 0 0 7583616 185392 72144 0 0 1766 1081 0 49 0 1 50
16 0 0 7583616 184816 72304 0 0 6300 6166 4 62 12 2 20
18 0 0 7583632 184480 72240 0 0 2814 1754 2 58 4 1 35
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch/loongarch/Kconfig')
| -rw-r--r-- | arch/loongarch/Kconfig | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index ddc042895d01..b81d0eba5c7e 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -649,6 +649,17 @@ config PARAVIRT over full virtualization. However, when run without a hypervisor the kernel is theoretically slower and slightly larger. +config PARAVIRT_TIME_ACCOUNTING + bool "Paravirtual steal time accounting" + depends on PARAVIRT + help + Select this option to enable fine granularity task steal time + accounting. Time spent executing other tasks in parallel with + the current vCPU is discounted from the vCPU power. To account for + that, there can be a small performance impact. + + If in doubt, say N here. + endmenu config ARCH_SELECT_MEMORY_MODEL |