Re: [Xen-devel] [PATCH v2] xl: add memory allocation logic for numa platform

[Juergen Gross <juergen.gross@xxxxxxxxxxxxxx>]

Hi again,

sorry, didn't spot it before: you should use the generic cpumap functions
(libxl_cpumap_alloc, libxl_cpumap_test, libxl_cpumap_set, libxl_cpumap_reset)
and the libxl_cpumap type for the cpumaps.
This will remove the little overkill of using an asm construct for setting
a bit, too.

On 08/09/2011 07:52 AM, Zhang, Yang Z wrote:
> Thanks Juergen's comments. Here is the revised patch which add cpupool check.
>
> For numa platform, we need to allocate memory for guest on which guest cpu 
> reside.
> This patch add this feature for xl. Just use the simple algorithm to select the 
> best node.
>
> Signed-off-by: Zhang Yang<yang.z.zhang@xxxxxxxxx>
>
> diff -r 9aa47ef52e4d tools/libxl/libxl.c
> --- a/tools/libxl/libxl.c       Mon Jul 04 06:08:05 2011 +0800
> +++ b/tools/libxl/libxl.c       Fri Aug 12 13:51:41 2011 +0800
> @@ -2259,6 +2259,108 @@
>       return ERROR_FAIL;
>   }
>
> +static inline void set_bit(int nr, volatile void *addr)
> +{
> +    asm volatile (
> +      "btsl %1,%0"
> +       : "=m" (ADDR)
> +       : "Ir" (nr), "m" (ADDR) : "memory");
This breaks other architectures (e.g. ia64).

> +}
> +
> +int libxl_get_numainfo(libxl_ctx *ctx, libxl_numainfo_t *numainfo)
> +{
> +    xc_numainfo_t ninfo = { 0 };
> +    libxl_physinfo physinfo = { 0 };
> +    libxl_topologyinfo topoinfo;
> +    int i,  max_nodes, max_cpus, node;
> +    libxl_nodeinfo_t *nodeinfo;
> +    DECLARE_HYPERCALL_BUFFER(xc_node_to_memsize_t, node_memsize);
> +    DECLARE_HYPERCALL_BUFFER(xc_node_to_memfree_t, node_memfree);
> +
> +    if (libxl_get_physinfo(ctx,&physinfo))
> +        goto out;
> +
> +    max_cpus = physinfo.max_cpu_id + 1;
> +    max_nodes = NUMA_NO_NODE + 1;
> +    numainfo->max_cpus = max_cpus;
> +
> +    numainfo->cpu_to_node = calloc(max_cpus, sizeof (unsigned long));
> +    if (numainfo->cpu_to_node == NULL)
> +        goto out;
> +
> +    numainfo->nodeinfo = (char *)calloc(max_nodes, sizeof(libxl_nodeinfo_t));
> +    if (numainfo->nodeinfo == NULL)
> +        goto out;
> +
> +    nodeinfo = (libxl_nodeinfo_t *)numainfo->nodeinfo;
> +    node_memsize = xc_hypercall_buffer_alloc(ctx->xch, node_memsize, 
> sizeof(*node_memsize) * max_nodes);
> +    if ( node_memsize == NULL )
> +        goto out;
> +    node_memfree = xc_hypercall_buffer_alloc(ctx->xch, node_memfree, 
> sizeof(*node_memfree) * max_nodes);
> +    if ( node_memfree == NULL )
> +        goto out;
> +
> +    set_xen_guest_handle(ninfo.node_to_memsize, node_memsize);
> +    set_xen_guest_handle(ninfo.node_to_memfree, node_memfree);
> +    ninfo.max_node_index = max_nodes - 1;
> +
> +    if ( xc_numainfo(ctx->xch,&ninfo) != 0 )
> +        goto out;
> +
> +    max_nodes = ninfo.max_node_index + 1;
> +    numainfo->max_nodes = max_nodes;
> +
> +    if (libxl_get_topologyinfo(ctx,&topoinfo))
> +        goto out;
> +
> +    for ( i = 0; i<= max_nodes; i++ ) {
> +        if (node_memsize[i] != INVALID_MEM_NODE) {
> +            nodeinfo[i].online = 1;
> +            nodeinfo[i].cpumap = malloc(BITS_TO_LONGS(max_cpus) * sizeof 
> (unsigned long));
> +            bzero(nodeinfo[i].cpumap, BITS_TO_LONGS(max_cpus) * sizeof 
> (unsigned long));
> +
> +            /* Total Memory */
> +            nodeinfo[i].total_memkb = node_memsize[i]>>  10; /* KB */
> +
> +            /* Free Memory */
> +            nodeinfo[i].free_memkb = node_memfree[i]>>  10; /* KB */
> +        } else
> +            nodeinfo[i].online = 0;
> +    }
> +
> +    for (i = 0; i<  max_cpus; i++)
> +        if (topoinfo.coremap.array[i] != LIBXL_CPUARRAY_INVALID_ENTRY) {
> +            node = topoinfo.nodemap.array[i];
> +            set_bit(i, nodeinfo[node].cpumap);
> +            numainfo->cpu_to_node[i] = node;
> +        }
> +    libxl_topologyinfo_destroy(&topoinfo);
> +
> +    xc_hypercall_buffer_free(ctx->xch, node_memsize);
> +    xc_hypercall_buffer_free(ctx->xch, node_memfree);
> +    return 0;
> +
> +out:
> +    if (numainfo->cpu_to_node)
> +        free(numainfo->cpu_to_node);
> +    if (numainfo->nodeinfo);
> +        free(numainfo->nodeinfo);
> +    xc_hypercall_buffer_free(ctx->xch, node_memsize);
> +    xc_hypercall_buffer_free(ctx->xch, node_memfree);
> +    return ERROR_FAIL;
> +}
> +
> +void libxl_free_numainfo(libxl_numainfo_t *numainfo)
> +{
> +    int i;
> +    libxl_nodeinfo_t *nodeinfo = (libxl_nodeinfo_t *)numainfo->nodeinfo;
> +
> +    for(i = 0; i<  numainfo->max_nodes; i++)
> +        if(nodeinfo[i].cpumap)
> +            free(nodeinfo[i].cpumap);
> +    free(numainfo->cpu_to_node);
> +    free(numainfo->nodeinfo);
> +}
>   const libxl_version_info* libxl_get_version_info(libxl_ctx *ctx)
>   {
>       union {
> diff -r 9aa47ef52e4d tools/libxl/libxl.h
> --- a/tools/libxl/libxl.h       Mon Jul 04 06:08:05 2011 +0800
> +++ b/tools/libxl/libxl.h       Fri Aug 12 13:51:41 2011 +0800
> @@ -496,6 +496,16 @@
>
>   int libxl_get_physinfo(libxl_ctx *ctx, libxl_physinfo *physinfo);
>   int libxl_get_topologyinfo(libxl_ctx *ctx, libxl_topologyinfo *info);
> +
> +#define NUMA_NO_NODE    0xFF
> +#define INVALID_MEM_NODE     0ul
> +#define BITS_PER_LONG (sizeof(unsigned long) * 8)
> +#define BITS_TO_LONGS(bits) (((bits)+BITS_PER_LONG-1)/BITS_PER_LONG)
> +#define ADDR (*(volatile long *) addr)
> +
> +int libxl_get_numainfo(libxl_ctx *ctx, libxl_numainfo_t *numainfo);
> +void libxl_free_numainfo(libxl_numainfo_t *numainfo);
> +
>   libxl_vcpuinfo *libxl_list_vcpu(libxl_ctx *ctx, uint32_t domid,
>                                          int *nb_vcpu, int *nrcpus);
>   int libxl_set_vcpuaffinity(libxl_ctx *ctx, uint32_t domid, uint32_t vcpuid,
> diff -r 9aa47ef52e4d tools/libxl/libxl.idl
> --- a/tools/libxl/libxl.idl     Mon Jul 04 06:08:05 2011 +0800
> +++ b/tools/libxl/libxl.idl     Fri Aug 12 13:51:41 2011 +0800
> @@ -291,6 +291,19 @@
>       ("socketmap", libxl_cpuarray, False, "cpu to socket map"),
>       ("nodemap", libxl_cpuarray,   False, "cpu to node map"),
>       ])
> +libxl_nodeinfo = Struct("nodeinfo_t", [
> +    ("free_memkb", uint32),
> +    ("total_memkb", uint32),
> +    ("candidate", uint32),
> +    ("online", uint32),
> +    ("cpumap", string),
> +    ])
> +libxl_numainfo = Struct("numainfo_t", [
> +    ("nodeinfo", string),
> +    ("max_nodes", uint32),
> +    ("cpu_to_node", string),
> +    ("max_cpus", uint32),
> +    ])
>
>   libxl_sched_credit = Struct("sched_credit", [
>       ("weight", integer),
> diff -r 9aa47ef52e4d tools/libxl/libxl_create.c
> --- a/tools/libxl/libxl_create.c        Mon Jul 04 06:08:05 2011 +0800
> +++ b/tools/libxl/libxl_create.c        Fri Aug 12 13:51:41 2011 +0800
> @@ -143,17 +143,110 @@
>           console->build_state = state;
>       return 0;
>   }
> +static int find_best_node(libxl_ctx *ctx, libxl_numainfo_t *numainfo)
> +{
> +    int nr_doms, i, j, nr_vcpu, nrcpus, best_node, pcpu, node_id;
> +    unsigned long max_nodes = numainfo->max_nodes;
> +    unsigned long *nodeload;
> +    libxl_dominfo *dominfo;
> +    libxl_vcpuinfo *vcpuinfo;
> +    libxl_nodeinfo_t *nodeinfo = (libxl_nodeinfo_t *)numainfo->nodeinfo;
> +
> +    nodeload = malloc(max_nodes * sizeof(*nodeload));
> +    bzero(nodeload, max_nodes * sizeof(*nodeload));
> +
> +    if (!(dominfo = libxl_list_domain(ctx,&nr_doms)))
> +        goto out;
> +
> +    for (i = 0; i<  nr_doms; i++) {
> +        vcpuinfo = libxl_list_vcpu(ctx, dominfo[i].domid,&nr_vcpu,&nrcpus);
> +        if (!vcpuinfo)
> +            goto out;
> +        for (j = 0; j<  nr_vcpu; j++) {
> +            if (!vcpuinfo[j].online)
> +                continue;
> +            pcpu = vcpuinfo[j].cpu;
> +            node_id = numainfo->cpu_to_node[pcpu];
> +            if (nodeinfo[node_id].candidate)
> +                nodeload[node_id]++;
> +            else
> +                nodeload[node_id] += 8;
> +        }
> +        free(vcpuinfo);
> +    }
> +    best_node = 0;
> +    for (i = 1; i<  max_nodes; i++)
> +        if(nodeinfo[i].candidate&&  nodeinfo[i].online
> +&&  nodeload[i]<  nodeload[best_node])
> +            best_node = i;
> +
> +    return best_node;
> +out:
> +    if (dominfo)
> +        free(dominfo);
> +    return -1;
> +}
> +
> +static int libxl_node_select(libxl_ctx *ctx, libxl_domain_build_info *b_info, 
> uint32_t domid)
> +{
> +    unsigned long i, best_node;
> +    unsigned long needmem = b_info->max_memkb;
> +    libxl_numainfo_t numainfo ={ 0 };
> +    libxl_nodeinfo_t *nodeinfo;
> +    libxl_cpupoolinfo *poolinfo;
> +    int n_pools;
> +
> +    poolinfo = libxl_list_cpupool(ctx,&n_pools);
> +    for (i = 0; i<  n_pools; i++)
> +         libxl_cpupoolinfo_destroy(poolinfo + i);
> +     if (n_pools>  1) {
> +         printf("cpupools are being used - skip numa optimization.\n");
> +         return 0;
> +    }
> +
> +
> +    if (libxl_get_numainfo(ctx,&numainfo)) {
> +        fprintf(stderr, "libxl_get_topologyinfo failed.\n");
> +        return -1;
> +    }
> +
> +    if (numainfo.max_nodes<  2) {
> +        printf("max_nodes = %d\n", numainfo.max_nodes);
> +        return 0;
> +        }
> +
> +    nodeinfo = (libxl_nodeinfo_t *)numainfo.nodeinfo;
> +    for (i = 0; i<  numainfo.max_nodes; i++)
> +        if (nodeinfo[i].free_memkb>  needmem)
> +            nodeinfo[i].candidate = 1;
> +
> +    best_node = find_best_node(ctx,&numainfo);
> +    if (best_node == -1) {
> +        libxl_numainfo_t_destroy(&numainfo);
> +        return -1;
> +    }
> +
> +    for (i = 0; i<  b_info->max_vcpus; i++)
> +        xc_vcpu_setaffinity(ctx->xch, domid, i, (uint8_t 
> *)(nodeinfo[best_node].cpumap));
> +
> +    libxl_numainfo_t_destroy(&numainfo);
> +    return 0;
> +}
>
>   int libxl__domain_build(libxl__gc *gc, libxl_domain_build_info *info, 
> uint32_t domid, libxl_domain_build_state *state)
>   {
>       char **vments = NULL, **localents = NULL;
>       struct timeval start_time;
>       int i, ret;
> +    libxl_ctx *ctx = libxl__gc_owner(gc);
>
>       ret = libxl__build_pre(gc, domid, info, state);
>       if (ret)
>           goto out;
>
> +    if (libxl_node_select(ctx, info, domid))
> +        printf("Cannot find best node, using defaul algorithm\n");
> +
>       gettimeofday(&start_time, NULL);
>
>       if (info->hvm) {
Juergen

--
Juergen Gross                 Principal Developer Operating Systems
PDG ES&S SWE OS6                       Telephone: +49 (0) 89 3222 2967
Fujitsu Technology Solutions              e-mail: juergen.gross@xxxxxxxxxxxxxx
Domagkstr. 28                           Internet: ts.fujitsu.com
D-80807 Muenchen                 Company details: ts.fujitsu.com/imprint.html


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