apb: change pbm_pci_host prefix functions to use sabre_pci prefix
[qemu/ar7.git] / iothread.c
blobd8b6c1fb27b9499176da71229d88d2ad91c43265
1 /*
2 * Event loop thread
4 * Copyright Red Hat Inc., 2013
6 * Authors:
7 * Stefan Hajnoczi <stefanha@redhat.com>
9 * This work is licensed under the terms of the GNU GPL, version 2 or later.
10 * See the COPYING file in the top-level directory.
14 #include "qemu/osdep.h"
15 #include "qom/object.h"
16 #include "qom/object_interfaces.h"
17 #include "qemu/module.h"
18 #include "block/aio.h"
19 #include "block/block.h"
20 #include "sysemu/iothread.h"
21 #include "qmp-commands.h"
22 #include "qemu/error-report.h"
23 #include "qemu/rcu.h"
24 #include "qemu/main-loop.h"
26 typedef ObjectClass IOThreadClass;
28 #define IOTHREAD_GET_CLASS(obj) \
29 OBJECT_GET_CLASS(IOThreadClass, obj, TYPE_IOTHREAD)
30 #define IOTHREAD_CLASS(klass) \
31 OBJECT_CLASS_CHECK(IOThreadClass, klass, TYPE_IOTHREAD)
33 /* Benchmark results from 2016 on NVMe SSD drives show max polling times around
34 * 16-32 microseconds yield IOPS improvements for both iodepth=1 and iodepth=32
35 * workloads.
37 #define IOTHREAD_POLL_MAX_NS_DEFAULT 32768ULL
39 static __thread IOThread *my_iothread;
41 AioContext *qemu_get_current_aio_context(void)
43 return my_iothread ? my_iothread->ctx : qemu_get_aio_context();
46 static void *iothread_run(void *opaque)
48 IOThread *iothread = opaque;
50 rcu_register_thread();
52 my_iothread = iothread;
53 qemu_mutex_lock(&iothread->init_done_lock);
54 iothread->thread_id = qemu_get_thread_id();
55 qemu_cond_signal(&iothread->init_done_cond);
56 qemu_mutex_unlock(&iothread->init_done_lock);
58 while (iothread->running) {
59 aio_poll(iothread->ctx, true);
61 if (atomic_read(&iothread->worker_context)) {
62 GMainLoop *loop;
64 g_main_context_push_thread_default(iothread->worker_context);
65 iothread->main_loop =
66 g_main_loop_new(iothread->worker_context, TRUE);
67 loop = iothread->main_loop;
69 g_main_loop_run(iothread->main_loop);
70 iothread->main_loop = NULL;
71 g_main_loop_unref(loop);
73 g_main_context_pop_thread_default(iothread->worker_context);
77 rcu_unregister_thread();
78 return NULL;
81 /* Runs in iothread_run() thread */
82 static void iothread_stop_bh(void *opaque)
84 IOThread *iothread = opaque;
86 iothread->running = false; /* stop iothread_run() */
88 if (iothread->main_loop) {
89 g_main_loop_quit(iothread->main_loop);
93 void iothread_stop(IOThread *iothread)
95 if (!iothread->ctx || iothread->stopping) {
96 return;
98 iothread->stopping = true;
99 aio_bh_schedule_oneshot(iothread->ctx, iothread_stop_bh, iothread);
100 qemu_thread_join(&iothread->thread);
103 static int iothread_stop_iter(Object *object, void *opaque)
105 IOThread *iothread;
107 iothread = (IOThread *)object_dynamic_cast(object, TYPE_IOTHREAD);
108 if (!iothread) {
109 return 0;
111 iothread_stop(iothread);
112 return 0;
115 static void iothread_instance_init(Object *obj)
117 IOThread *iothread = IOTHREAD(obj);
119 iothread->poll_max_ns = IOTHREAD_POLL_MAX_NS_DEFAULT;
122 static void iothread_instance_finalize(Object *obj)
124 IOThread *iothread = IOTHREAD(obj);
126 iothread_stop(iothread);
127 if (iothread->worker_context) {
128 g_main_context_unref(iothread->worker_context);
129 iothread->worker_context = NULL;
131 qemu_cond_destroy(&iothread->init_done_cond);
132 qemu_mutex_destroy(&iothread->init_done_lock);
133 if (!iothread->ctx) {
134 return;
136 aio_context_unref(iothread->ctx);
139 static void iothread_complete(UserCreatable *obj, Error **errp)
141 Error *local_error = NULL;
142 IOThread *iothread = IOTHREAD(obj);
143 char *name, *thread_name;
145 iothread->stopping = false;
146 iothread->running = true;
147 iothread->thread_id = -1;
148 iothread->ctx = aio_context_new(&local_error);
149 if (!iothread->ctx) {
150 error_propagate(errp, local_error);
151 return;
154 aio_context_set_poll_params(iothread->ctx,
155 iothread->poll_max_ns,
156 iothread->poll_grow,
157 iothread->poll_shrink,
158 &local_error);
159 if (local_error) {
160 error_propagate(errp, local_error);
161 aio_context_unref(iothread->ctx);
162 iothread->ctx = NULL;
163 return;
166 qemu_mutex_init(&iothread->init_done_lock);
167 qemu_cond_init(&iothread->init_done_cond);
168 iothread->once = (GOnce) G_ONCE_INIT;
170 /* This assumes we are called from a thread with useful CPU affinity for us
171 * to inherit.
173 name = object_get_canonical_path_component(OBJECT(obj));
174 thread_name = g_strdup_printf("IO %s", name);
175 qemu_thread_create(&iothread->thread, thread_name, iothread_run,
176 iothread, QEMU_THREAD_JOINABLE);
177 g_free(thread_name);
178 g_free(name);
180 /* Wait for initialization to complete */
181 qemu_mutex_lock(&iothread->init_done_lock);
182 while (iothread->thread_id == -1) {
183 qemu_cond_wait(&iothread->init_done_cond,
184 &iothread->init_done_lock);
186 qemu_mutex_unlock(&iothread->init_done_lock);
189 typedef struct {
190 const char *name;
191 ptrdiff_t offset; /* field's byte offset in IOThread struct */
192 } PollParamInfo;
194 static PollParamInfo poll_max_ns_info = {
195 "poll-max-ns", offsetof(IOThread, poll_max_ns),
197 static PollParamInfo poll_grow_info = {
198 "poll-grow", offsetof(IOThread, poll_grow),
200 static PollParamInfo poll_shrink_info = {
201 "poll-shrink", offsetof(IOThread, poll_shrink),
204 static void iothread_get_poll_param(Object *obj, Visitor *v,
205 const char *name, void *opaque, Error **errp)
207 IOThread *iothread = IOTHREAD(obj);
208 PollParamInfo *info = opaque;
209 int64_t *field = (void *)iothread + info->offset;
211 visit_type_int64(v, name, field, errp);
214 static void iothread_set_poll_param(Object *obj, Visitor *v,
215 const char *name, void *opaque, Error **errp)
217 IOThread *iothread = IOTHREAD(obj);
218 PollParamInfo *info = opaque;
219 int64_t *field = (void *)iothread + info->offset;
220 Error *local_err = NULL;
221 int64_t value;
223 visit_type_int64(v, name, &value, &local_err);
224 if (local_err) {
225 goto out;
228 if (value < 0) {
229 error_setg(&local_err, "%s value must be in range [0, %"PRId64"]",
230 info->name, INT64_MAX);
231 goto out;
234 *field = value;
236 if (iothread->ctx) {
237 aio_context_set_poll_params(iothread->ctx,
238 iothread->poll_max_ns,
239 iothread->poll_grow,
240 iothread->poll_shrink,
241 &local_err);
244 out:
245 error_propagate(errp, local_err);
248 static void iothread_class_init(ObjectClass *klass, void *class_data)
250 UserCreatableClass *ucc = USER_CREATABLE_CLASS(klass);
251 ucc->complete = iothread_complete;
253 object_class_property_add(klass, "poll-max-ns", "int",
254 iothread_get_poll_param,
255 iothread_set_poll_param,
256 NULL, &poll_max_ns_info, &error_abort);
257 object_class_property_add(klass, "poll-grow", "int",
258 iothread_get_poll_param,
259 iothread_set_poll_param,
260 NULL, &poll_grow_info, &error_abort);
261 object_class_property_add(klass, "poll-shrink", "int",
262 iothread_get_poll_param,
263 iothread_set_poll_param,
264 NULL, &poll_shrink_info, &error_abort);
267 static const TypeInfo iothread_info = {
268 .name = TYPE_IOTHREAD,
269 .parent = TYPE_OBJECT,
270 .class_init = iothread_class_init,
271 .instance_size = sizeof(IOThread),
272 .instance_init = iothread_instance_init,
273 .instance_finalize = iothread_instance_finalize,
274 .interfaces = (InterfaceInfo[]) {
275 {TYPE_USER_CREATABLE},
280 static void iothread_register_types(void)
282 type_register_static(&iothread_info);
285 type_init(iothread_register_types)
287 char *iothread_get_id(IOThread *iothread)
289 return object_get_canonical_path_component(OBJECT(iothread));
292 AioContext *iothread_get_aio_context(IOThread *iothread)
294 return iothread->ctx;
297 static int query_one_iothread(Object *object, void *opaque)
299 IOThreadInfoList ***prev = opaque;
300 IOThreadInfoList *elem;
301 IOThreadInfo *info;
302 IOThread *iothread;
304 iothread = (IOThread *)object_dynamic_cast(object, TYPE_IOTHREAD);
305 if (!iothread) {
306 return 0;
309 info = g_new0(IOThreadInfo, 1);
310 info->id = iothread_get_id(iothread);
311 info->thread_id = iothread->thread_id;
312 info->poll_max_ns = iothread->poll_max_ns;
313 info->poll_grow = iothread->poll_grow;
314 info->poll_shrink = iothread->poll_shrink;
316 elem = g_new0(IOThreadInfoList, 1);
317 elem->value = info;
318 elem->next = NULL;
320 **prev = elem;
321 *prev = &elem->next;
322 return 0;
325 IOThreadInfoList *qmp_query_iothreads(Error **errp)
327 IOThreadInfoList *head = NULL;
328 IOThreadInfoList **prev = &head;
329 Object *container = object_get_objects_root();
331 object_child_foreach(container, query_one_iothread, &prev);
332 return head;
335 void iothread_stop_all(void)
337 Object *container = object_get_objects_root();
338 BlockDriverState *bs;
339 BdrvNextIterator it;
341 for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
342 AioContext *ctx = bdrv_get_aio_context(bs);
343 if (ctx == qemu_get_aio_context()) {
344 continue;
346 aio_context_acquire(ctx);
347 bdrv_set_aio_context(bs, qemu_get_aio_context());
348 aio_context_release(ctx);
351 object_child_foreach(container, iothread_stop_iter, NULL);
354 static gpointer iothread_g_main_context_init(gpointer opaque)
356 AioContext *ctx;
357 IOThread *iothread = opaque;
358 GSource *source;
360 iothread->worker_context = g_main_context_new();
362 ctx = iothread_get_aio_context(iothread);
363 source = aio_get_g_source(ctx);
364 g_source_attach(source, iothread->worker_context);
365 g_source_unref(source);
367 aio_notify(iothread->ctx);
368 return NULL;
371 GMainContext *iothread_get_g_main_context(IOThread *iothread)
373 g_once(&iothread->once, iothread_g_main_context_init, iothread);
375 return iothread->worker_context;
378 IOThread *iothread_create(const char *id, Error **errp)
380 Object *obj;
382 obj = object_new_with_props(TYPE_IOTHREAD,
383 object_get_internal_root(),
384 id, errp, NULL);
386 return IOTHREAD(obj);
389 void iothread_destroy(IOThread *iothread)
391 object_unparent(OBJECT(iothread));
394 /* Lookup IOThread by its id. Only finds user-created objects, not internal
395 * iothread_create() objects. */
396 IOThread *iothread_by_id(const char *id)
398 return IOTHREAD(object_resolve_path_type(id, TYPE_IOTHREAD, NULL));