Commit ea089eeb authored by Igor Mammedov's avatar Igor Mammedov Committed by Eduardo Habkost
Browse files

numa: move source of default CPUs to NUMA node mapping into boards 



Originally CPU threads were by default assigned in
round-robin fashion. However it was causing issues in
guest since CPU threads from the same socket/core could
be placed on different NUMA nodes.
Commit fb43b73b (pc: fix default VCPU to NUMA node mapping)
fixed it by grouping threads within a socket on the same node
introducing cpu_index_to_socket_id() callback and commit
20bb648d (spapr: Fix default NUMA node allocation for threads)
reused callback to fix similar issues for SPAPR machine
even though socket doesn't make much sense there.

As result QEMU ended up having 3 default distribution rules
used by 3 targets /virt-arm, spapr, pc/.

In effort of moving NUMA mapping for CPUs into possible_cpus,
generalize default mapping in numa.c by making boards decide
on default mapping and let them explicitly tell generic
numa code to which node a CPU thread belongs to by replacing
cpu_index_to_socket_id() with @cpu_index_to_instance_props()
which provides default node_id assigned by board to specified
cpu_index.

Signed-off-by: default avatarIgor Mammedov <imammedo@redhat.com>
Reviewed-by: default avatarEduardo Habkost <ehabkost@redhat.com>
Message-Id: <1494415802-227633-2-git-send-email-imammedo@redhat.com>
Reviewed-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: default avatarEduardo Habkost <ehabkost@redhat.com>
parent d9c34f9c

hw/arm/virt.c

+18 −2
Original line number Diff line number Diff line
@@ -1539,6 +1539,16 @@ static void virt_set_gic_version(Object *obj, const char *value, Error **errp) 
    }

}



static CpuInstanceProperties

virt_cpu_index_to_props(MachineState *ms, unsigned cpu_index)

{

    MachineClass *mc = MACHINE_GET_CLASS(ms);

    const CPUArchIdList *possible_cpus = mc->possible_cpu_arch_ids(ms);



    assert(cpu_index < possible_cpus->len);

    return possible_cpus->cpus[cpu_index].props;

}



static const CPUArchIdList *virt_possible_cpu_arch_ids(MachineState *ms)

{

    int n;
@@ -1558,8 +1568,13 @@ static const CPUArchIdList *virt_possible_cpu_arch_ids(MachineState *ms) 
        ms->possible_cpus->cpus[n].props.has_thread_id = true;

        ms->possible_cpus->cpus[n].props.thread_id = n;



        /* TODO: add 'has_node/node' here to describe

           to which node core belongs */

        /* default distribution of CPUs over NUMA nodes */

        if (nb_numa_nodes) {

            /* preset values but do not enable them i.e. 'has_node_id = false',

             * numa init code will enable them later if manual mapping wasn't

             * present on CLI */

            ms->possible_cpus->cpus[n].props.node_id = n % nb_numa_nodes;

        }

    }

    return ms->possible_cpus;

}
@@ -1581,6 +1596,7 @@ static void virt_machine_class_init(ObjectClass *oc, void *data) 
    /* We know we will never create a pre-ARMv7 CPU which needs 1K pages */

    mc->minimum_page_bits = 12;

    mc->possible_cpu_arch_ids = virt_possible_cpu_arch_ids;

    mc->cpu_index_to_instance_props = virt_cpu_index_to_props;

}



static const TypeInfo virt_machine_info = {

hw/i386/pc.c

+17 −6
Original line number Diff line number Diff line
@@ -2243,12 +2243,14 @@ static void pc_machine_reset(void) 
    }

}



static unsigned pc_cpu_index_to_socket_id(unsigned cpu_index)

static CpuInstanceProperties

pc_cpu_index_to_props(MachineState *ms, unsigned cpu_index)

{

    X86CPUTopoInfo topo;

    x86_topo_ids_from_idx(smp_cores, smp_threads, cpu_index,

                          &topo);

    return topo.pkg_id;

    MachineClass *mc = MACHINE_GET_CLASS(ms);

    const CPUArchIdList *possible_cpus = mc->possible_cpu_arch_ids(ms);



    assert(cpu_index < possible_cpus->len);

    return possible_cpus->cpus[cpu_index].props;

}



static const CPUArchIdList *pc_possible_cpu_arch_ids(MachineState *ms)
@@ -2280,6 +2282,15 @@ static const CPUArchIdList *pc_possible_cpu_arch_ids(MachineState *ms) 
        ms->possible_cpus->cpus[i].props.core_id = topo.core_id;

        ms->possible_cpus->cpus[i].props.has_thread_id = true;

        ms->possible_cpus->cpus[i].props.thread_id = topo.smt_id;



        /* default distribution of CPUs over NUMA nodes */

        if (nb_numa_nodes) {

            /* preset values but do not enable them i.e. 'has_node_id = false',

             * numa init code will enable them later if manual mapping wasn't

             * present on CLI */

            ms->possible_cpus->cpus[i].props.node_id =

                topo.pkg_id % nb_numa_nodes;

        }

    }

    return ms->possible_cpus;

}
@@ -2322,7 +2333,7 @@ static void pc_machine_class_init(ObjectClass *oc, void *data) 
    pcmc->acpi_data_size = 0x20000 + 0x8000;

    pcmc->save_tsc_khz = true;

    mc->get_hotplug_handler = pc_get_hotpug_handler;

    mc->cpu_index_to_socket_id = pc_cpu_index_to_socket_id;

    mc->cpu_index_to_instance_props = pc_cpu_index_to_props;

    mc->possible_cpu_arch_ids = pc_possible_cpu_arch_ids;

    mc->has_hotpluggable_cpus = true;

    mc->default_boot_order = "cad";

hw/ppc/spapr.c

+21 −7
Original line number Diff line number Diff line
@@ -2981,11 +2981,18 @@ static HotplugHandler *spapr_get_hotplug_handler(MachineState *machine, 
    return NULL;

}



static unsigned spapr_cpu_index_to_socket_id(unsigned cpu_index)

static CpuInstanceProperties

spapr_cpu_index_to_props(MachineState *machine, unsigned cpu_index)

{

    /* Allocate to NUMA nodes on a "socket" basis (not that concept of

     * socket means much for the paravirtualized PAPR platform) */

    return cpu_index / smp_threads / smp_cores;

    CPUArchId *core_slot;

    MachineClass *mc = MACHINE_GET_CLASS(machine);



    /* make sure possible_cpu are intialized */

    mc->possible_cpu_arch_ids(machine);

    /* get CPU core slot containing thread that matches cpu_index */

    core_slot = spapr_find_cpu_slot(machine, cpu_index, NULL);

    assert(core_slot);

    return core_slot->props;

}



static const CPUArchIdList *spapr_possible_cpu_arch_ids(MachineState *machine)
@@ -3012,8 +3019,15 @@ static const CPUArchIdList *spapr_possible_cpu_arch_ids(MachineState *machine) 
        machine->possible_cpus->cpus[i].arch_id = core_id;

        machine->possible_cpus->cpus[i].props.has_core_id = true;

        machine->possible_cpus->cpus[i].props.core_id = core_id;

        /* TODO: add 'has_node/node' here to describe

           to which node core belongs */



        /* default distribution of CPUs over NUMA nodes */

        if (nb_numa_nodes) {

            /* preset values but do not enable them i.e. 'has_node_id = false',

             * numa init code will enable them later if manual mapping wasn't

             * present on CLI */

            machine->possible_cpus->cpus[i].props.node_id =

                core_id / smp_threads / smp_cores % nb_numa_nodes;

        }

    }

    return machine->possible_cpus;

}
@@ -3138,7 +3152,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data) 
    hc->pre_plug = spapr_machine_device_pre_plug;

    hc->plug = spapr_machine_device_plug;

    hc->unplug = spapr_machine_device_unplug;

    mc->cpu_index_to_socket_id = spapr_cpu_index_to_socket_id;

    mc->cpu_index_to_instance_props = spapr_cpu_index_to_props;

    mc->possible_cpu_arch_ids = spapr_possible_cpu_arch_ids;

    hc->unplug_request = spapr_machine_device_unplug_request;

include/hw/boards.h

+6 −2
Original line number Diff line number Diff line
@@ -74,7 +74,10 @@ typedef struct { 
 *    of HotplugHandler object, which handles hotplug operation

 *    for a given @dev. It may return NULL if @dev doesn't require

 *    any actions to be performed by hotplug handler.

 * @cpu_index_to_socket_id:

 * @cpu_index_to_instance_props:

 *    used to provide @cpu_index to socket/core/thread number mapping, allowing

 *    legacy code to perform maping from cpu_index to topology properties

 *    Returns: tuple of socket/core/thread ids given cpu_index belongs to.

 *    used to provide @cpu_index to socket number mapping, allowing

 *    a machine to group CPU threads belonging to the same socket/package

 *    Returns: socket number given cpu_index belongs to.
@@ -141,7 +144,8 @@ struct MachineClass { 


    HotplugHandler *(*get_hotplug_handler)(MachineState *machine,

                                           DeviceState *dev);

    unsigned (*cpu_index_to_socket_id)(unsigned cpu_index);

    CpuInstanceProperties (*cpu_index_to_instance_props)(MachineState *machine,

                                                         unsigned cpu_index);

    const CPUArchIdList *(*possible_cpu_arch_ids)(MachineState *machine);

};

include/sysemu/numa.h

+1 −1
Original line number Diff line number Diff line
@@ -26,7 +26,7 @@ struct node_info { 
};



extern NodeInfo numa_info[MAX_NODES];

void parse_numa_opts(MachineClass *mc);

void parse_numa_opts(MachineState *ms);

void numa_post_machine_init(void);

void query_numa_node_mem(uint64_t node_mem[]);

extern QemuOptsList qemu_numa_opts;