hostmem: introduce "prealloc-threads" property
the property will allow user to specify number of threads to use
in pre-allocation stage. It also will allow to reduce implicit
hostmem dependency on current_machine.
On object creation it will default to 1, but via machine
compat property it will be updated to MachineState::smp::cpus
to keep current behavior for hostmem and main RAM (which is
now also hostmem based).
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20200219160953.13771-77-imammedo@redhat.com>
diff --git a/backends/hostmem.c b/backends/hostmem.c
index e773bdf..0988986 100644
--- a/backends/hostmem.c
+++ b/backends/hostmem.c
@@ -223,7 +223,6 @@
{
Error *local_err = NULL;
HostMemoryBackend *backend = MEMORY_BACKEND(obj);
- MachineState *ms = MACHINE(qdev_get_machine());
if (backend->force_prealloc) {
if (value) {
@@ -243,7 +242,7 @@
void *ptr = memory_region_get_ram_ptr(&backend->mr);
uint64_t sz = memory_region_size(&backend->mr);
- os_mem_prealloc(fd, ptr, sz, ms->smp.cpus, &local_err);
+ os_mem_prealloc(fd, ptr, sz, backend->prealloc_threads, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
@@ -252,14 +251,45 @@
}
}
+static void host_memory_backend_get_prealloc_threads(Object *obj, Visitor *v,
+ const char *name, void *opaque, Error **errp)
+{
+ HostMemoryBackend *backend = MEMORY_BACKEND(obj);
+ visit_type_uint32(v, name, &backend->prealloc_threads, errp);
+}
+
+static void host_memory_backend_set_prealloc_threads(Object *obj, Visitor *v,
+ const char *name, void *opaque, Error **errp)
+{
+ HostMemoryBackend *backend = MEMORY_BACKEND(obj);
+ Error *local_err = NULL;
+ uint32_t value;
+
+ visit_type_uint32(v, name, &value, &local_err);
+ if (local_err) {
+ goto out;
+ }
+ if (value <= 0) {
+ error_setg(&local_err,
+ "property '%s' of %s doesn't take value '%d'",
+ name, object_get_typename(obj), value);
+ goto out;
+ }
+ backend->prealloc_threads = value;
+out:
+ error_propagate(errp, local_err);
+}
+
static void host_memory_backend_init(Object *obj)
{
HostMemoryBackend *backend = MEMORY_BACKEND(obj);
MachineState *machine = MACHINE(qdev_get_machine());
+ /* TODO: convert access to globals to compat properties */
backend->merge = machine_mem_merge(machine);
backend->dump = machine_dump_guest_core(machine);
backend->prealloc = mem_prealloc;
+ backend->prealloc_threads = 1;
}
static void host_memory_backend_post_init(Object *obj)
@@ -313,7 +343,6 @@
{
HostMemoryBackend *backend = MEMORY_BACKEND(uc);
HostMemoryBackendClass *bc = MEMORY_BACKEND_GET_CLASS(uc);
- MachineState *ms = MACHINE(qdev_get_machine());
Error *local_err = NULL;
void *ptr;
uint64_t sz;
@@ -378,7 +407,7 @@
*/
if (backend->prealloc) {
os_mem_prealloc(memory_region_get_fd(&backend->mr), ptr, sz,
- ms->smp.cpus, &local_err);
+ backend->prealloc_threads, &local_err);
if (local_err) {
goto out;
}
@@ -456,6 +485,12 @@
host_memory_backend_set_prealloc, &error_abort);
object_class_property_set_description(oc, "prealloc",
"Preallocate memory", &error_abort);
+ object_class_property_add(oc, "prealloc-threads", "int",
+ host_memory_backend_get_prealloc_threads,
+ host_memory_backend_set_prealloc_threads,
+ NULL, NULL, &error_abort);
+ object_class_property_set_description(oc, "prealloc-threads",
+ "Number of CPU threads to use for prealloc", &error_abort);
object_class_property_add(oc, "size", "int",
host_memory_backend_get_size,
host_memory_backend_set_size,
diff --git a/include/sysemu/hostmem.h b/include/sysemu/hostmem.h
index 5db0d66..bdf8666 100644
--- a/include/sysemu/hostmem.h
+++ b/include/sysemu/hostmem.h
@@ -61,6 +61,7 @@
* @parent: opaque parent object container
* @size: amount of memory backend provides
* @mr: MemoryRegion representing host memory belonging to backend
+ * @prealloc_threads: number of threads to be used for preallocatining RAM
*/
struct HostMemoryBackend {
/* private */
@@ -70,6 +71,7 @@
uint64_t size;
bool merge, dump, use_canonical_path;
bool prealloc, force_prealloc, is_mapped, share;
+ uint32_t prealloc_threads;
DECLARE_BITMAP(host_nodes, MAX_NODES + 1);
HostMemPolicy policy;
diff --git a/vl.c b/vl.c
index 15cc5bd..afc682e 100644
--- a/vl.c
+++ b/vl.c
@@ -2828,8 +2828,7 @@
}
}
-static void create_default_memdev(MachineState *ms, const char *path,
- bool prealloc)
+static void create_default_memdev(MachineState *ms, const char *path)
{
Object *obj;
MachineClass *mc = MACHINE_GET_CLASS(ms);
@@ -2838,7 +2837,6 @@
if (path) {
object_property_set_str(obj, path, "mem-path", &error_fatal);
}
- object_property_set_bool(obj, prealloc, "prealloc", &error_fatal);
object_property_set_int(obj, ms->ram_size, "size", &error_fatal);
object_property_add_child(object_get_objects_root(), mc->default_ram_id,
obj, &error_fatal);
@@ -3980,6 +3978,14 @@
exit(1);
}
+ if (mem_prealloc) {
+ char *val;
+
+ val = g_strdup_printf("%d", current_machine->smp.cpus);
+ object_register_sugar_prop("memory-backend", "prealloc-threads", val);
+ g_free(val);
+ }
+
/*
* Get the default machine options from the machine if it is not already
* specified either by the configuration file or by the command line.
@@ -4307,7 +4313,7 @@
if (machine_class->default_ram_id && current_machine->ram_size &&
numa_uses_legacy_mem() && !current_machine->ram_memdev_id) {
- create_default_memdev(current_machine, mem_path, mem_prealloc);
+ create_default_memdev(current_machine, mem_path);
}
/* do monitor/qmp handling at preconfig state if requested */
main_loop();
