Re: [Qemu-devel] [PATCH 5/7] NUMA: add qmp command set-mpol to set memory policy for NUMA node

[Wanlong Gao <gaowanlong@cn.fujitsu.com>]

On 06/18/2013 05:21 PM, Paolo Bonzini wrote:
> Il 18/06/2013 10:09, Wanlong Gao ha scritto:
>> The QMP command let it be able to set node's memory policy
>> through the QMP protocol. The qmp-shell command is like:
>>     set-mpol nodeid=0 mpol=membind nodemask=0-1
>>
>> Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
> 
> How would this work with mem-path?

This can also set mempolicy for mem-path backed memory in
guest nodes. So we don't need to know if we are using
mem-path.

Thanks,
Wanlong Gao

> 
> Paolo
> 
>> ---
>>  cpus.c                  | 61 +++++++++++++++++++++++++++++++++++++++++++++++++
>>  include/sysemu/sysemu.h |  1 +
>>  qapi-schema.json        | 13 +++++++++++
>>  qmp-commands.hx         | 35 ++++++++++++++++++++++++++++
>>  vl.c                    |  2 +-
>>  5 files changed, 111 insertions(+), 1 deletion(-)
>>
>> diff --git a/cpus.c b/cpus.c
>> index b868932..a2836e9 100644
>> --- a/cpus.c
>> +++ b/cpus.c
>> @@ -1431,3 +1431,64 @@ void qmp_inject_nmi(Error **errp)
>>      error_set(errp, QERR_UNSUPPORTED);
>>  #endif
>>  }
>> +
>> +void qmp_set_mpol(int64_t nodeid, bool has_mpol, const char *mpol,
>> +                  bool has_nodemask, const char *nodemask, Error **errp)
>> +{
>> +    unsigned int ret;
>> +    unsigned int flags;
>> +    DECLARE_BITMAP(host_mem, MAX_CPUMASK_BITS);
>> +
>> +    if (nodeid >= nb_numa_nodes) {
>> +        error_setg(errp, "Only has '%d' NUMA nodes", nb_numa_nodes);
>> +        return;
>> +    }
>> +
>> +    bitmap_copy(host_mem, numa_info[nodeid].host_mem, MAX_CPUMASK_BITS);
>> +    flags = numa_info[nodeid].flags;
>> +
>> +    numa_info[nodeid].flags = NODE_HOST_NONE;
>> +    bitmap_zero(numa_info[nodeid].host_mem, MAX_CPUMASK_BITS);
>> +
>> +    if (!has_mpol) {
>> +        if (set_node_mpol(nodeid) == -1) {
>> +            goto error;
>> +        }
>> +        return;
>> +    }
>> +
>> +    if (!strcmp(mpol, "membind")) {
>> +        numa_info[nodeid].flags |= NODE_HOST_BIND;
>> +    } else if (!strcmp(mpol, "interleave")) {
>> +        numa_info[nodeid].flags |= NODE_HOST_INTERLEAVE;
>> +    } else if (!strcmp(mpol, "preferred")) {
>> +        numa_info[nodeid].flags |= NODE_HOST_PREFERRED;
>> +    } else {
>> +        error_setg(errp, "Invalid NUMA policy '%s'", mpol);
>> +        goto error;
>> +    }
>> +
>> +    if (!has_nodemask) {
>> +        bitmap_fill(numa_info[nodeid].host_mem, MAX_CPUMASK_BITS);
>> +    }
>> +
>> +    if (nodemask) {
>> +        ret = numa_node_parse_mpol(nodemask, numa_info[nodeid].host_mem);
>> +    }
>> +    if (ret == 4) {
>> +        goto error;
>> +    } else if (ret & 1) {
>> +        numa_info[nodeid].flags |= NODE_HOST_RELATIVE;
>> +    }
>> +
>> +    if (set_node_mpol(nodeid) == -1) {
>> +        goto error;
>> +    }
>> +
>> +    return;
>> +
>> +error:
>> +    bitmap_copy(numa_info[nodeid].host_mem, host_mem, MAX_CPUMASK_BITS);
>> +    numa_info[nodeid].flags = flags;
>> +    return;
>> +}
>> diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
>> index 993b8e0..7d804af 100644
>> --- a/include/sysemu/sysemu.h
>> +++ b/include/sysemu/sysemu.h
>> @@ -144,6 +144,7 @@ struct node_info {
>>      unsigned int flags;
>>  };
>>  extern struct node_info numa_info[MAX_NODES];
>> +extern unsigned int numa_node_parse_mpol(const char *str, unsigned long *bm);
>>  
>>  #define MAX_OPTION_ROMS 16
>>  typedef struct QEMUOptionRom {
>> diff --git a/qapi-schema.json b/qapi-schema.json
>> index a80ee40..403c703 100644
>> --- a/qapi-schema.json
>> +++ b/qapi-schema.json
>> @@ -3608,3 +3608,16 @@
>>              '*cpuid-input-ecx': 'int',
>>              'cpuid-register': 'X86CPURegister32',
>>              'features': 'int' } }
>> +
>> +# @set-mpol:
>> +#
>> +# Set the host memory binding policy for guest NUMA node.
>> +#
>> +# @node-id: The node ID of guest NUMA node to set memory policy to.
>> +#
>> +# @mpol: The memory policy string to set.
>> +#
>> +# Since: 1.6.0
>> +##
>> +{ 'command': 'set-mpol', 'data': {'nodeid': 'int', '*mpol': 'str',
>> +                                  '*nodemask': 'str'} }
>> diff --git a/qmp-commands.hx b/qmp-commands.hx
>> index 8cea5e5..930c844 100644
>> --- a/qmp-commands.hx
>> +++ b/qmp-commands.hx
>> @@ -2997,3 +2997,38 @@ Example:
>>  <- { "return": {} }
>>  
>>  EQMP
>> +
>> +    {
>> +        .name      = "set-mpol",
>> +        .args_type = "nodeid:i,mpol:s?,nodemask:s?",
>> +        .help      = "Set the host memory binding policy for guest NUMA node",
>> +        .mhandler.cmd_new = qmp_marshal_input_set_mpol,
>> +    },
>> +
>> +SQMP
>> +set-mpol
>> +------
>> +
>> +Set the host memory binding policy for guest NUMA node
>> +
>> +Arguments:
>> +
>> +- "nodeid": The nodeid of guest NUMA node to set memory policy to.
>> +              (json-int)
>> +- "mpol": The memory policy string to set.
>> +           (json-string, optional)
>> +- "nodemask": The node mask contained to mpol.
>> +                (json-string, optional)
>> +
>> +Example:
>> +
>> +-> { "execute": "set-mpol", "arguments": { "nodeid": 0, "mpol": "membind",
>> +                                           "nodemask": "0-1" }}
>> +<- { "return": {} }
>> +
>> +Notes:
>> +    1. If "mpol" is not set, the memory policy of this "nodeid" will be set
>> +       to "default".
>> +    2. If "nodemask" is not set, the node mask of this "mpol" will be set
>> +       to "all".
>> +EQMP
>> diff --git a/vl.c b/vl.c
>> index ada9fb2..73af85e 100644
>> --- a/vl.c
>> +++ b/vl.c
>> @@ -1348,7 +1348,7 @@ error:
>>      exit(1);
>>  }
>>  
>> -static unsigned int numa_node_parse_mpol(const char *str, unsigned long *bm)
>> +unsigned int numa_node_parse_mpol(const char *str, unsigned long *bm)
>>  {
>>      unsigned long long value, endvalue;
>>      char *endptr;
>>
> 
>