diff options
| -rw-r--r-- | migration/migration.c | 14 | ||||
| -rw-r--r-- | migration/migration.h | 15 | ||||
| -rw-r--r-- | migration/ram.c | 16 |
3 files changed, 34 insertions, 11 deletions
diff --git a/migration/migration.c b/migration/migration.c index 409eb3e916..1c6c81ad49 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -1763,6 +1763,16 @@ static void mark_source_rp_bad(MigrationState *s) s->rp_state.error = true; } +void migration_rp_wait(MigrationState *s) +{ + qemu_sem_wait(&s->rp_state.rp_sem); +} + +void migration_rp_kick(MigrationState *s) +{ + qemu_sem_post(&s->rp_state.rp_sem); +} + static struct rp_cmd_args { ssize_t len; /* -1 = variable */ const char *name; @@ -1835,7 +1845,7 @@ static int migrate_handle_rp_resume_ack(MigrationState *s, uint32_t value) MIGRATION_STATUS_POSTCOPY_ACTIVE); /* Notify send thread that time to continue send pages */ - qemu_sem_post(&s->rp_state.rp_sem); + migration_rp_kick(s); return 0; } @@ -2464,7 +2474,7 @@ static int postcopy_resume_handshake(MigrationState *s) qemu_savevm_send_postcopy_resume(s->to_dst_file); while (s->state == MIGRATION_STATUS_POSTCOPY_RECOVER) { - qemu_sem_wait(&s->rp_state.rp_sem); + migration_rp_wait(s); } if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) { diff --git a/migration/migration.h b/migration/migration.h index 4106a1dc54..cd5534337c 100644 --- a/migration/migration.h +++ b/migration/migration.h @@ -316,6 +316,12 @@ struct MigrationState { * be cleared in the rp_thread! */ bool rp_thread_created; + /* + * Used to synchronize between migration main thread and return + * path thread. The migration thread can wait() on this sem, while + * other threads (e.g., return path thread) can kick it using a + * post(). + */ QemuSemaphore rp_sem; /* * We post to this when we got one PONG from dest. So far it's an @@ -527,4 +533,13 @@ void migration_populate_vfio_info(MigrationInfo *info); void migration_reset_vfio_bytes_transferred(void); void postcopy_temp_page_reset(PostcopyTmpPage *tmp_page); +/* Migration thread waiting for return path thread. */ +void migration_rp_wait(MigrationState *s); +/* + * Kick the migration thread waiting for return path messages. NOTE: the + * name can be slightly confusing (when read as "kick the rp thread"), just + * to remember the target is always the migration thread. + */ +void migration_rp_kick(MigrationState *s); + #endif diff --git a/migration/ram.c b/migration/ram.c index 6c40d9af0c..2f5ce4d60b 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -4141,7 +4141,7 @@ static int ram_dirty_bitmap_sync_all(MigrationState *s, RAMState *rs) /* Wait until all the ramblocks' dirty bitmap synced */ while (qatomic_read(&rs->postcopy_bmap_sync_requested)) { - qemu_sem_wait(&s->rp_state.rp_sem); + migration_rp_wait(s); } trace_ram_dirty_bitmap_sync_complete(); @@ -4149,11 +4149,6 @@ static int ram_dirty_bitmap_sync_all(MigrationState *s, RAMState *rs) return 0; } -static void ram_dirty_bitmap_reload_notify(MigrationState *s) -{ - qemu_sem_post(&s->rp_state.rp_sem); -} - /* * Read the received bitmap, revert it as the initial dirty bitmap. * This is only used when the postcopy migration is paused but wants @@ -4237,10 +4232,13 @@ int ram_dirty_bitmap_reload(MigrationState *s, RAMBlock *block) qatomic_dec(&rs->postcopy_bmap_sync_requested); /* - * We succeeded to sync bitmap for current ramblock. If this is - * the last one to sync, we need to notify the main send thread. + * We succeeded to sync bitmap for current ramblock. Always kick the + * migration thread to check whether all requested bitmaps are + * reloaded. NOTE: it's racy to only kick when requested==0, because + * we don't know whether the migration thread may still be increasing + * it. */ - ram_dirty_bitmap_reload_notify(s); + migration_rp_kick(s); ret = 0; out: |