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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH V5 03/32] xl / libxl: push VCPU affinity pinning down to libxl
This patch introduces a key value list called "vcpu_affinity" in libxl
IDL to preserve VCPU to PCPU mapping. This is necessary for libxl to
preserve all information to construct a domain.
Also define LIBXL_HAVE_AFFINITY_KEY_VALUE_LIST in libxl.h to mark the
change in API.
Signed-off-by: Wei Liu <wei.liu2@xxxxxxxxxx>
Cc: Dario Faggioli <dario.faggioli@xxxxxxxxxx>
---
tools/libxl/libxl.h | 12 +++++++
tools/libxl/libxl_dom.c | 48 ++++++++++++++++++++++++++++
tools/libxl/libxl_types.idl | 1 +
tools/libxl/xl_cmdimpl.c | 74 ++++++++++++++++---------------------------
4 files changed, 89 insertions(+), 46 deletions(-)
diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
index 2b06094..a5a5155 100644
--- a/tools/libxl/libxl.h
+++ b/tools/libxl/libxl.h
@@ -302,6 +302,18 @@
#endif
/*
+ * LIBXL_HAVE_VCPU_AFFINITY_KEY_VALUE_LIST
+ *
+ * If this is defined, then libxl_domain_build_info structure will
+ * contain vcpu_affinity, a libxl_key_value_list type that contains
+ * the necessary information to pin a VCPU to a PCPU. Libxl will try
+ * to pin VCPUs to PCPUs according to this list.
+ *
+ * The key is the ID of VCPU and the value is the ID of PCPU.
+ */
+#define LIBXL_HAVE_VCPU_AFFINITY_KEY_VALUE_LIST 1
+
+/*
* LIBXL_HAVE_BUILDINFO_USBDEVICE_LIST
*
* If this is defined, then the libxl_domain_build_info structure will
diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index 661999c..b818815 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -263,6 +263,54 @@ int libxl__build_pre(libxl__gc *gc, uint32_t domid,
libxl_domain_set_nodeaffinity(ctx, domid, &info->nodemap);
libxl_set_vcpuaffinity_all(ctx, domid, info->max_vcpus, &info->cpumap);
+ /* If we have vcpu affinity list, pin vcpu to pcpu. */
+ if (d_config->b_info.vcpu_affinity) {
+ int i;
+ libxl_bitmap vcpu_cpumap;
+ int *vcpu_to_pcpu, sz = sizeof(int) * d_config->b_info.max_vcpus;
+
+ vcpu_to_pcpu = libxl__zalloc(gc, sz);
+ memset(vcpu_to_pcpu, -1, sz);
+
+ for (i = 0; i < d_config->b_info.max_vcpus; i++) {
+ libxl_key_value_list kvl = d_config->b_info.vcpu_affinity;
+ const char *key, *val;
+ int k, v;
+
+ key = kvl[i * 2];
+ if (!key)
+ break;
+ val = kvl[i * 2 + 1];
+
+ k = atoi(key);
+ v = atoi(val);
+ vcpu_to_pcpu[k] = v;
+ }
+
+ rc = libxl_cpu_bitmap_alloc(ctx, &vcpu_cpumap, 0);
+ if (rc) {
+ libxl_bitmap_dispose(&vcpu_cpumap);
+ return ERROR_FAIL;
+ }
+
+ for (i = 0; i < d_config->b_info.max_vcpus; i++) {
+ if (vcpu_to_pcpu[i] != -1) {
+ libxl_bitmap_set_none(&vcpu_cpumap);
+ libxl_bitmap_set(&vcpu_cpumap, vcpu_to_pcpu[i]);
+ } else {
+ libxl_bitmap_set_any(&vcpu_cpumap);
+ }
+ if (libxl_set_vcpuaffinity(ctx, domid, i, &vcpu_cpumap)) {
+ LIBXL__LOG(ctx, LIBXL__LOG_ERROR,
+ "setting affinity failed on vcpu `%d'.", i);
+ libxl_bitmap_dispose(&vcpu_cpumap);
+ return ERROR_FAIL;
+ }
+ }
+
+ libxl_bitmap_dispose(&vcpu_cpumap);
+ }
+
if (xc_domain_setmaxmem(ctx->xch, domid, info->target_memkb +
LIBXL_MAXMEM_CONSTANT) < 0) {
LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Couldn't set max memory");
diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
index 0dfafe7..7b0901c 100644
--- a/tools/libxl/libxl_types.idl
+++ b/tools/libxl/libxl_types.idl
@@ -305,6 +305,7 @@ libxl_domain_build_info = Struct("domain_build_info",[
("avail_vcpus", libxl_bitmap),
("cpumap", libxl_bitmap),
("nodemap", libxl_bitmap),
+ ("vcpu_affinity", libxl_key_value_list),
("numa_placement", libxl_defbool),
("tsc_mode", libxl_tsc_mode),
("max_memkb", MemKB),
diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index a1cb5b8..3200d40 100644
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -88,9 +88,6 @@ xlchild children[child_max];
static const char *common_domname;
static int fd_lock = -1;
-/* Stash for specific vcpu to pcpu mappping */
-static int *vcpu_to_pcpu;
-
static const char savefileheader_magic[32]=
"Xen saved domain, xl format\n \0 \r";
@@ -804,26 +801,19 @@ static void parse_config_data(const char *config_source,
if (!xlu_cfg_get_list (config, "cpus", &cpus, 0, 1)) {
int n_cpus = 0;
+ libxl_key_value_list kvl = NULL;
+ int len = 0;
if (libxl_cpu_bitmap_alloc(ctx, &b_info->cpumap, 0)) {
fprintf(stderr, "Unable to allocate cpumap\n");
exit(1);
}
- /* Prepare the array for single vcpu to pcpu mappings */
- vcpu_to_pcpu = xmalloc(sizeof(int) * b_info->max_vcpus);
- memset(vcpu_to_pcpu, -1, sizeof(int) * b_info->max_vcpus);
-
- /*
- * Idea here is to let libxl think all the domain's vcpus
- * have cpu affinity with all the pcpus on the list.
- * It is then us, here in xl, that matches each single vcpu
- * to its pcpu (and that's why we need to stash such info in
- * the vcpu_to_pcpu array now) after the domain has been created.
- * Doing it like this saves the burden of passing to libxl
- * some big array hosting the single mappings. Also, using
- * the cpumap derived from the list ensures memory is being
- * allocated on the proper nodes anyway.
+ /* Construct key value list for vcpu affinity. The key is vcpu
+ * id, value is pcpu id.
+ *
+ * For example, for a list of ['2', '3'], we generate
+ * kvl = [ '0':'2', '1':'3' ]
*/
libxl_bitmap_set_none(&b_info->cpumap);
while ((buf = xlu_cfg_get_listitem(cpus, n_cpus)) != NULL) {
@@ -833,11 +823,30 @@ static void parse_config_data(const char *config_source,
exit(1);
}
libxl_bitmap_set(&b_info->cpumap, i);
- if (n_cpus < b_info->max_vcpus)
- vcpu_to_pcpu[n_cpus] = i;
+ if (n_cpus < b_info->max_vcpus) {
+ kvl = xrealloc(kvl, sizeof(char *) * (len * 2 + 2));
+ /* key */
+ if (asprintf(&kvl[len*2], "%d", n_cpus) == -1) {
+ LOG("failed to allocate memory for vcpu affinity list:
key");
+ exit(1);
+ }
+ /* value */
+ kvl[len*2+1] = strdup(buf);
+ if (!kvl[len*2+1]) {
+ LOG("failed to allocate memory for vcpu affinity list:
value");
+ exit(1);
+ }
+ len++;
+ }
n_cpus++;
}
+ /* One extra slot for sentinel */
+ kvl = xrealloc(kvl, sizeof(char *) * (len * 2 + 1));
+ kvl[len * 2] = NULL;
+
+ b_info->vcpu_affinity = kvl;
+
/* We have a cpumap, disable automatic placement */
libxl_defbool_set(&b_info->numa_placement, false);
}
@@ -2188,33 +2197,6 @@ start:
if ( ret )
goto error_out;
- /* If single vcpu to pcpu mapping was requested, honour it */
- if (vcpu_to_pcpu) {
- libxl_bitmap vcpu_cpumap;
-
- ret = libxl_cpu_bitmap_alloc(ctx, &vcpu_cpumap, 0);
- if (ret)
- goto error_out;
- for (i = 0; i < d_config.b_info.max_vcpus; i++) {
-
- if (vcpu_to_pcpu[i] != -1) {
- libxl_bitmap_set_none(&vcpu_cpumap);
- libxl_bitmap_set(&vcpu_cpumap, vcpu_to_pcpu[i]);
- } else {
- libxl_bitmap_set_any(&vcpu_cpumap);
- }
- if (libxl_set_vcpuaffinity(ctx, domid, i, &vcpu_cpumap)) {
- fprintf(stderr, "setting affinity failed on vcpu `%d'.\n", i);
- libxl_bitmap_dispose(&vcpu_cpumap);
- free(vcpu_to_pcpu);
- ret = ERROR_FAIL;
- goto error_out;
- }
- }
- libxl_bitmap_dispose(&vcpu_cpumap);
- free(vcpu_to_pcpu); vcpu_to_pcpu = NULL;
- }
-
ret = libxl_userdata_store(ctx, domid, "xl",
config_data, config_len);
if (ret) {
--
1.7.10.4
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