> From: Zhao Liu <[email protected]>
> Sent: Monday, February 13, 2023 5:50 PM
> To: Eduardo Habkost <[email protected]>; Marcel Apfelbaum
> <[email protected]>; Philippe Mathieu-Daudé <[email protected]>;
> Yanan Wang <[email protected]>; Michael S . Tsirkin
> <[email protected]>; Richard Henderson <[email protected]>; Paolo
> Bonzini <[email protected]>; Eric Blake <[email protected]>; Markus
> Armbruster <[email protected]>
> Cc: [email protected]; Wang, Zhenyu Z <[email protected]>; Mi,
> Dapeng1 <[email protected]>; Ding, Zhuocheng
> <[email protected]>; Robert Hoo <[email protected]>;
> Christopherson,, Sean <[email protected]>; Like Xu
> <[email protected]>; Liu, Zhao1 <[email protected]>
> Subject: [RFC 08/52] machine: Add helpers to get cpu topology info from
> MachineState.topo
>
> From: Zhao Liu <[email protected]>
>
> When MachineState.topo is introduced, the topology related structures become
> complicated. In the general case (hybrid or smp topology), accessing the
> topology information needs to determine whether it is currently smp or hybrid
> topology, and then access the corresponding MachineState.topo.smp or
> MachineState.topo.hybrid.
>
> The best way to do this is to wrap the access to the topology to avoid having
> to
> check each time it is accessed.
>
> The following helpers are provided here:
>
> - General interfaces - no need to worry about whether the underlying
> topology is smp or hybrid:
>
> * machine_topo_get_cpus()
> * machine_topo_get_max_cpus()
> * machine_topo_is_smp()
> * machine_topo_get_sockets()
> * machine_topo_get_dies()
> * machine_topo_get_clusters()
> * machine_topo_get_threads();
> * machine_topo_get_cores();
> * machine_topo_get_threads_by_idx()
> * machine_topo_get_cores_by_idx()
> * machine_topo_get_cores_per_socket()
> * machine_topo_get_threads_per_socket()
>
> - SMP-specific interfaces - provided for the cases that are clearly known to
> be
> smp topology:
>
> * machine_topo_get_smp_cores()
> * machine_topo_get_smp_threads()
>
> Since for hybrid topology, each core may has different threads, if someone
> wants "cpus per core", the cpu_index is need to target a specific core
> (machine_topo_get_threads_by_idx()). But for smp, there is no need to be so
> troublesome, so for this case, we provide smp-specific interfaces.
>
> Signed-off-by: Zhao Liu <[email protected]>
> ---
> hw/core/machine-topo.c | 142
> +++++++++++++++++++++++++++++++++++++++++
> include/hw/boards.h | 35 ++++++++++
> 2 files changed, 177 insertions(+)
>
> diff --git a/hw/core/machine-topo.c b/hw/core/machine-topo.c index
> 7223f73f99b0..b20160479629 100644
> --- a/hw/core/machine-topo.c
> +++ b/hw/core/machine-topo.c
> @@ -21,6 +21,148 @@
> #include "hw/boards.h"
> #include "qapi/error.h"
>
> +unsigned int machine_topo_get_sockets(const MachineState *ms) {
> + return machine_topo_is_smp(ms) ? ms->topo.smp.sockets :
> + ms->topo.hybrid.sockets; }
> +
> +unsigned int machine_topo_get_dies(const MachineState *ms) {
> + return machine_topo_is_smp(ms) ? ms->topo.smp.dies :
> + ms->topo.hybrid.dies; }
> +
> +unsigned int machine_topo_get_clusters(const MachineState *ms) {
> + return machine_topo_is_smp(ms) ? ms->topo.smp.clusters :
> + ms->topo.hybrid.clusters; }
> +
> +unsigned int machine_topo_get_smp_cores(const MachineState *ms) {
> + g_assert(machine_topo_is_smp(ms));
> + return ms->topo.smp.cores;
> +}
> +
> +unsigned int machine_topo_get_smp_threads(const MachineState *ms) {
> + g_assert(machine_topo_is_smp(ms));
> + return ms->topo.smp.threads;
> +}
> +
> +unsigned int machine_topo_get_threads(const MachineState *ms,
> + unsigned int cluster_id,
> + unsigned int core_id) {
> + if (machine_topo_is_smp(ms)) {
> + return ms->topo.smp.threads;
> + } else {
> + return ms->topo.hybrid.cluster_list[cluster_id]
> + .core_list[core_id].threads;
> + }
> +
> + return 0;
> +}
> +
> +unsigned int machine_topo_get_cores(const MachineState *ms,
> + unsigned int cluster_id) {
> + if (machine_topo_is_smp(ms)) {
> + return ms->topo.smp.cores;
> + } else {
> + return ms->topo.hybrid.cluster_list[cluster_id].cores;
> + }
> +}
> +
> +unsigned int machine_topo_get_threads_by_idx(const MachineState *ms,
> + unsigned int cpu_index) {
> + unsigned cpus_per_die;
> + unsigned tmp_idx;
> + HybridCluster *cluster;
> + HybridCore *core;
> +
> + if (machine_topo_is_smp(ms)) {
> + return ms->topo.smp.threads;
> + }
> +
> + cpus_per_die = ms->topo.max_cpus / (ms->topo.hybrid.sockets *
> + ms->topo.hybrid.dies);
> + tmp_idx = cpu_index % cpus_per_die;
> +
> + for (int i = 0; i < ms->topo.hybrid.clusters; i++) {
> + cluster = &ms->topo.hybrid.cluster_list[i];
> +
> + for (int j = 0; j < cluster->cores; j++) {
> + core = &cluster->core_list[j];
> +
> + if (tmp_idx < core->threads) {
> + return core->threads;
> + } else {
> + tmp_idx -= core->threads;
> + }
> + }
> + }
> +
> + return 0;
> +}
> +
> +unsigned int machine_topo_get_cores_by_idx(const MachineState *ms,
> + unsigned int cpu_index) {
> + unsigned cpus_per_die;
> + unsigned tmp_idx;
> + HybridCluster *cluster;
> + HybridCore *core;
> +
> + if (machine_topo_is_smp(ms)) {
> + return ms->topo.smp.cores;
> + }
> +
> + cpus_per_die = ms->topo.max_cpus / (ms->topo.hybrid.sockets *
> + ms->topo.hybrid.dies);
> + tmp_idx = cpu_index % cpus_per_die;
> +
> + for (int i = 0; i < ms->topo.hybrid.clusters; i++) {
> + cluster = &ms->topo.hybrid.cluster_list[i];
> +
> + for (int j = 0; j < cluster->cores; j++) {
> + core = &cluster->core_list[j];
> +
> + if (tmp_idx < core->threads) {
> + return cluster->cores;
> + } else {
> + tmp_idx -= core->threads;
> + }
> + }
> + }
> +
> + return 0;
> +}
> +
It looks most code of this function is same with previous function. Could we
extract
the same part code and define a low level function?
> +unsigned int machine_topo_get_cores_per_socket(const MachineState *ms)
> +{
> + unsigned int cores_per_die = 0;
> +
> + if (machine_topo_is_smp(ms)) {
> + return ms->topo.smp.cores * ms->topo.smp.clusters *
> ms->topo.smp.dies;
> + }
> +
> + for (int i = 0; i < ms->topo.hybrid.clusters; i++) {
> + cores_per_die += ms->topo.hybrid.cluster_list[i].cores;
> + }
> +
> + return cores_per_die * ms->topo.hybrid.dies; }
> +
> +unsigned int machine_topo_get_threads_per_socket(const MachineState
> +*ms) {
> + unsigned int sockets = machine_topo_is_smp(ms) ? ms->topo.smp.sockets :
> + ms->topo.hybrid.sockets;
> + return ms->topo.max_cpus / sockets; }
> +
> /*
> * Report information of a machine's supported CPU topology hierarchy.
> * Topology members will be ordered from the largest to the smallest diff
> --git
> a/include/hw/boards.h b/include/hw/boards.h index
> 0a61855499e3..34b64b012022 100644
> --- a/include/hw/boards.h
> +++ b/include/hw/boards.h
> @@ -461,4 +461,39 @@ extern const size_t hw_compat_2_2_len; extern
> GlobalProperty hw_compat_2_1[]; extern const size_t hw_compat_2_1_len;
>
> +static inline
> +unsigned int machine_topo_get_cpus(const MachineState *ms) {
> + return ms->topo.cpus;
> +}
> +
> +static inline
> +unsigned int machine_topo_get_max_cpus(const MachineState *ms) {
> + return ms->topo.max_cpus;
> +}
> +
> +static inline
> +bool machine_topo_is_smp(const MachineState *ms) {
> + return ms->topo.topo_type == CPU_TOPO_TYPE_SMP; }
> +
> +unsigned int machine_topo_get_sockets(const MachineState *ms); unsigned
> +int machine_topo_get_dies(const MachineState *ms); unsigned int
> +machine_topo_get_clusters(const MachineState *ms); unsigned int
> +machine_topo_get_smp_cores(const MachineState *ms); unsigned int
> +machine_topo_get_smp_threads(const MachineState *ms); unsigned int
> +machine_topo_get_threads(const MachineState *ms,
> + unsigned int cluster_id,
> + unsigned int core_id); unsigned
> +int machine_topo_get_cores(const MachineState *ms,
> + unsigned int cluster_id); unsigned
> +int machine_topo_get_threads_by_idx(const MachineState *ms,
> + unsigned int cpu_index);
> +unsigned int machine_topo_get_cores_by_idx(const MachineState *ms,
> + unsigned int cpu_index);
> +unsigned int machine_topo_get_cores_per_socket(const MachineState *ms);
> +unsigned int machine_topo_get_threads_per_socket(const MachineState
> +*ms);
> +
> #endif
> --
> 2.34.1
