qemu/softmmu
Yanan Wang 864c3b5c32 hw/core/machine: Introduce CPU cluster topology support
The new Cluster-Aware Scheduling support has landed in Linux 5.16,
which has been proved to benefit the scheduling performance (e.g.
load balance and wake_affine strategy) on both x86_64 and AArch64.

So now in Linux 5.16 we have four-level arch-neutral CPU topology
definition like below and a new scheduler level for clusters.
struct cpu_topology {
    int thread_id;
    int core_id;
    int cluster_id;
    int package_id;
    int llc_id;
    cpumask_t thread_sibling;
    cpumask_t core_sibling;
    cpumask_t cluster_sibling;
    cpumask_t llc_sibling;
}

A cluster generally means a group of CPU cores which share L2 cache
or other mid-level resources, and it is the shared resources that
is used to improve scheduler's behavior. From the point of view of
the size range, it's between CPU die and CPU core. For example, on
some ARM64 Kunpeng servers, we have 6 clusters in each NUMA node,
and 4 CPU cores in each cluster. The 4 CPU cores share a separate
L2 cache and a L3 cache tag, which brings cache affinity advantage.

In virtualization, on the Hosts which have pClusters (physical
clusters), if we can design a vCPU topology with cluster level for
guest kernel and have a dedicated vCPU pinning. A Cluster-Aware
Guest kernel can also make use of the cache affinity of CPU clusters
to gain similar scheduling performance.

This patch adds infrastructure for CPU cluster level topology
configuration and parsing, so that the user can specify cluster
parameter if their machines support it.

Signed-off-by: Yanan Wang <wangyanan55@huawei.com>
Message-Id: <20211228092221.21068-3-wangyanan55@huawei.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[PMD: Added '(since 7.0)' to @clusters in qapi/machine.json]
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2021-12-31 13:42:39 +01:00
..
arch_init.c meson.build: Define QEMU_ARCH in config-target.h 2021-08-26 17:02:00 +01:00
balloon.c qapi: Restrict balloon-related commands to machine code 2020-09-29 15:41:35 +02:00
bootdevice.c softmmu: move more files to softmmu/ 2020-10-12 11:50:21 -04:00
cpu-throttle.c cpu-throttle: Remove timer_mod() from cpu_throttle_set() 2021-02-08 15:15:32 +01:00
cpu-timers.c icount: get rid of static variable 2021-04-01 09:40:45 +02:00
cpus.c misc: Remove redundant new line in perror() 2021-07-09 18:42:46 +02:00
datadir.c vl: extract softmmu/datadir.c 2020-12-10 12:15:18 -05:00
device_tree.c device_tree: Add qemu_fdt_add_path 2021-10-20 18:17:54 -07:00
dma-helpers.c dma: Let dma_buf_rw() propagate MemTxResult 2021-12-31 01:05:27 +01:00
globals.c qmp: generalize watchdog-set-action to -no-reboot/-no-shutdown 2020-12-15 12:51:57 -05:00
icount.c icount: get rid of static variable 2021-04-01 09:40:45 +02:00
ioport.c softmmu: Add missing trace-events file 2020-09-09 17:15:18 +01:00
main.c meson: move SDL and SDL-image detection to meson 2020-08-21 06:30:44 -04:00
memory.c memory: Introduce replay_discarded callback for RamDiscardManager 2021-11-01 22:56:44 +01:00
memory_mapping.c softmmu/memory_mapping: optimize for RamDiscardManager sections 2021-10-02 08:43:22 +02:00
meson.build seccomp: convert to meson 2021-01-06 10:21:20 +01:00
physmem.c accel/tcg: suppress IRQ check for special TBs 2021-11-29 15:12:37 +00:00
qdev-monitor.c pci,pc,virtio: bugfixes 2021-11-15 21:56:15 +01:00
qemu-seccomp.c seccomp: don't block getters for resource control syscalls 2021-07-14 14:15:52 +01:00
qtest.c qtest: add a QOM object for qtest 2021-05-26 14:49:45 +02:00
rtc.c qom: Allow optional sugar props 2021-02-08 16:57:37 +11:00
runstate-action.c runstate: cleanup reboot and panic actions 2021-01-21 13:00:41 +01:00
runstate.c runstate: Initialize Error * to NULL 2021-06-15 17:17:09 +02:00
timers-state.h qemu/atomic: Add aligned_{int64,uint64}_t types 2021-07-21 07:45:38 -10:00
tpm.c qapi: More complex uses of QAPI_LIST_APPEND 2021-01-28 08:08:45 +01:00
trace-events memory: make global_dirty_tracking a bitmask 2021-11-01 22:56:43 +01:00
trace.h softmmu: Add missing trace-events file 2020-09-09 17:15:18 +01:00
vl.c hw/core/machine: Introduce CPU cluster topology support 2021-12-31 13:42:39 +01:00