pve-qemu/debian/patches/pve/0043-move-savevm-async-back...

112 lines
3.9 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Wolfgang Bumiller <w.bumiller@proxmox.com>
Date: Thu, 30 Apr 2020 15:55:37 +0200
Subject: [PATCH] move savevm-async back into a coroutine
Move qemu_savevm_state_{header,setup} into the main loop and
the rest of the iteration into a coroutine. The former need
to lock the iothread (and we can't unlock it in the
coroutine), and the latter can't deal with being in a
separate thread, so a coroutine it must be.
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
---
savevm-async.c | 28 +++++++++-------------------
1 file changed, 9 insertions(+), 19 deletions(-)
diff --git a/savevm-async.c b/savevm-async.c
index a38b15d652..af865b9a0a 100644
--- a/savevm-async.c
+++ b/savevm-async.c
@@ -51,7 +51,7 @@ static struct SnapshotState {
QEMUFile *file;
int64_t total_time;
QEMUBH *cleanup_bh;
- QemuThread thread;
+ Coroutine *co;
} snap_state;
SaveVMInfo *qmp_query_savevm(Error **errp)
@@ -201,11 +201,9 @@ static void process_savevm_cleanup(void *opaque)
int ret;
qemu_bh_delete(snap_state.cleanup_bh);
snap_state.cleanup_bh = NULL;
+ snap_state.co = NULL;
qemu_savevm_state_cleanup();
- qemu_mutex_unlock_iothread();
- qemu_thread_join(&snap_state.thread);
- qemu_mutex_lock_iothread();
ret = save_snapshot_cleanup();
if (ret < 0) {
save_snapshot_error("save_snapshot_cleanup error %d", ret);
@@ -221,18 +219,13 @@ static void process_savevm_cleanup(void *opaque)
}
}
-static void *process_savevm_thread(void *opaque)
+static void process_savevm_coro(void *opaque)
{
int ret;
int64_t maxlen;
MigrationState *ms = migrate_get_current();
- rcu_register_thread();
-
- qemu_savevm_state_header(snap_state.file);
- qemu_savevm_state_setup(snap_state.file);
ret = qemu_file_get_error(snap_state.file);
-
if (ret < 0) {
save_snapshot_error("qemu_savevm_state_setup failed");
goto out;
@@ -247,16 +240,13 @@ static void *process_savevm_thread(void *opaque)
maxlen = blk_getlength(snap_state.target) - 30*1024*1024;
if (pending_size > 400000 && snap_state.bs_pos + pending_size < maxlen) {
- qemu_mutex_lock_iothread();
ret = qemu_savevm_state_iterate(snap_state.file, false);
if (ret < 0) {
save_snapshot_error("qemu_savevm_state_iterate error %d", ret);
break;
}
- qemu_mutex_unlock_iothread();
DPRINTF("savevm inerate pending size %lu ret %d\n", pending_size, ret);
} else {
- qemu_mutex_lock_iothread();
qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, NULL);
ret = global_state_store();
if (ret) {
@@ -285,16 +275,12 @@ static void *process_savevm_thread(void *opaque)
}
qemu_bh_schedule(snap_state.cleanup_bh);
- qemu_mutex_unlock_iothread();
out:
/* set migration state accordingly and clear soon-to-be stale file */
migrate_set_state(&ms->state, MIGRATION_STATUS_SETUP,
ret ? MIGRATION_STATUS_FAILED : MIGRATION_STATUS_COMPLETED);
ms->to_dst_file = NULL;
-
- rcu_unregister_thread();
- return NULL;
}
void qmp_savevm_start(bool has_statefile, const char *statefile, Error **errp)
@@ -373,8 +359,12 @@ void qmp_savevm_start(bool has_statefile, const char *statefile, Error **errp)
snap_state.state = SAVE_STATE_ACTIVE;
snap_state.cleanup_bh = qemu_bh_new(process_savevm_cleanup, &snap_state);
- qemu_thread_create(&snap_state.thread, "savevm-async", process_savevm_thread,
- NULL, QEMU_THREAD_JOINABLE);
+ snap_state.co = qemu_coroutine_create(&process_savevm_coro, NULL);
+ qemu_mutex_unlock_iothread();
+ qemu_savevm_state_header(snap_state.file);
+ qemu_savevm_state_setup(snap_state.file);
+ qemu_mutex_lock_iothread();
+ aio_co_schedule(iohandler_get_aio_context(), snap_state.co);
return;