[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH 09/16] migration: Drop cached migration state in migration_maybe_
From: |
Peter Xu |
Subject: |
[PATCH 09/16] migration: Drop cached migration state in migration_maybe_pause() |
Date: |
Tue, 14 Jan 2025 18:07:39 -0500 |
I can't see why we must cache the state now after we avoided possible
CANCEL race: that's the only thing I can think of that can modify the
migration state concurrently with the migration thread itself. Make all
the state updates to happen always, then we don't need to cache the state
anymore.
Signed-off-by: Peter Xu <peterx@redhat.com>
---
migration/migration.c | 27 ++++++++-------------------
1 file changed, 8 insertions(+), 19 deletions(-)
diff --git a/migration/migration.c b/migration/migration.c
index 5c688059de..5850c90c9f 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -102,9 +102,7 @@ static MigrationIncomingState *current_incoming;
static GSList *migration_blockers[MIG_MODE__MAX];
static bool migration_object_check(MigrationState *ms, Error **errp);
-static int migration_maybe_pause(MigrationState *s,
- int *current_active_state,
- int new_state);
+static int migration_maybe_pause(MigrationState *s, int new_state);
static void migrate_fd_cancel(MigrationState *s);
static bool close_return_path_on_source(MigrationState *s);
static void migration_completion_end(MigrationState *s);
@@ -2502,7 +2500,6 @@ static int postcopy_start(MigrationState *ms, Error
**errp)
int ret;
QIOChannelBuffer *bioc;
QEMUFile *fb;
- int cur_state = MIGRATION_STATUS_ACTIVE;
/*
* Now we're 100% sure to switch to postcopy, so JSON writer won't be
@@ -2537,8 +2534,7 @@ static int postcopy_start(MigrationState *ms, Error
**errp)
goto fail;
}
- ret = migration_maybe_pause(ms, &cur_state,
- MIGRATION_STATUS_POSTCOPY_ACTIVE);
+ ret = migration_maybe_pause(ms, MIGRATION_STATUS_POSTCOPY_ACTIVE);
if (ret < 0) {
error_setg_errno(errp, -ret, "%s: Failed in migration_maybe_pause()",
__func__);
@@ -2676,9 +2672,7 @@ fail:
* migrate_pause_before_switchover called with the BQL locked
* Returns: 0 on success
*/
-static int migration_maybe_pause(MigrationState *s,
- int *current_active_state,
- int new_state)
+static int migration_maybe_pause(MigrationState *s, int new_state)
{
if (!migrate_pause_before_switchover()) {
return 0;
@@ -2701,21 +2695,19 @@ static int migration_maybe_pause(MigrationState *s,
* wait for the 'pause_sem' semaphore.
*/
if (s->state != MIGRATION_STATUS_CANCELLING) {
- migrate_set_state(&s->state, *current_active_state,
+ migrate_set_state(&s->state, s->state,
MIGRATION_STATUS_PRE_SWITCHOVER);
bql_unlock();
qemu_sem_wait(&s->pause_sem);
bql_lock();
migrate_set_state(&s->state, MIGRATION_STATUS_PRE_SWITCHOVER,
new_state);
- *current_active_state = new_state;
}
return s->state == new_state ? 0 : -EINVAL;
}
-static int migration_completion_precopy(MigrationState *s,
- int *current_active_state)
+static int migration_completion_precopy(MigrationState *s)
{
int ret;
@@ -2728,8 +2720,7 @@ static int migration_completion_precopy(MigrationState *s,
}
}
- ret = migration_maybe_pause(s, current_active_state,
- MIGRATION_STATUS_DEVICE);
+ ret = migration_maybe_pause(s, MIGRATION_STATUS_DEVICE);
if (ret < 0) {
goto out_unlock;
}
@@ -2782,11 +2773,10 @@ static void
migration_completion_postcopy(MigrationState *s)
static void migration_completion(MigrationState *s)
{
int ret = 0;
- int current_active_state = s->state;
Error *local_err = NULL;
if (s->state == MIGRATION_STATUS_ACTIVE) {
- ret = migration_completion_precopy(s, ¤t_active_state);
+ ret = migration_completion_precopy(s);
} else if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
migration_completion_postcopy(s);
} else {
@@ -2826,8 +2816,7 @@ fail:
error_free(local_err);
}
- migrate_set_state(&s->state, current_active_state,
- MIGRATION_STATUS_FAILED);
+ migrate_set_state(&s->state, s->state, MIGRATION_STATUS_FAILED);
}
/**
--
2.47.0
- [PATCH 06/16] migration: Synchronize all CPU states only for non-iterable dump, (continued)
- [PATCH 06/16] migration: Synchronize all CPU states only for non-iterable dump, Peter Xu, 2025/01/14
- [PATCH 08/16] migration: Adjust locking in migration_maybe_pause(), Peter Xu, 2025/01/14
- [PATCH 07/16] migration: Adjust postcopy bandwidth during switchover, Peter Xu, 2025/01/14
- [PATCH 10/16] migration: Take BQL slightly longer in postcopy_start(), Peter Xu, 2025/01/14
- [PATCH 12/16] migration: Unwrap qemu_savevm_state_complete_precopy() in postcopy, Peter Xu, 2025/01/14
- [PATCH 13/16] migration: Cleanup qemu_savevm_state_complete_precopy(), Peter Xu, 2025/01/14
- [PATCH 11/16] migration: Notify COMPLETE once for postcopy, Peter Xu, 2025/01/14
- [PATCH 14/16] migration: Always set DEVICE state, Peter Xu, 2025/01/14
- [PATCH 15/16] migration: Merge precopy/postcopy on switchover start, Peter Xu, 2025/01/14
- [PATCH 16/16] migration: Trivial cleanup on JSON writer of vmstate_save(), Peter Xu, 2025/01/14
- [PATCH 09/16] migration: Drop cached migration state in migration_maybe_pause(),
Peter Xu <=
- Re: [PATCH 00/16] migration: Switchover phase refactoring, Jiri Denemark, 2025/01/15
- Re: [PATCH 00/16] migration: Switchover phase refactoring, Juraj Marcin, 2025/01/15
- Re: [PATCH 00/16] migration: Switchover phase refactoring, Fabiano Rosas, 2025/01/15