From b61e15d1ead74c97c9fa709f6d2868529bae1098 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 22 Feb 2013 17:36:20 +0100 Subject: [PATCH] migration: prepare to access s->state outside critical sections Accessing s->state outside the big QEMU lock will simplify a bit the locking/unlocking of the iothread lock. We need to keep the lock in migrate_fd_error and migrate_fd_completed, however, because they call migrate_fd_cleanup. Reviewed-by: Orit Wasserman Reviewed-by: Juan Quintela Signed-off-by: Paolo Bonzini Signed-off-by: Juan Quintela (cherry picked from commit f4410a5d9926886c36d9fa9fdd969d0469d62724) --- migration.c | 33 +++++++++++++++++++++------------ 1 file changed, 21 insertions(+), 12 deletions(-) diff --git a/migration.c b/migration.c index c0a9239..e844b2c 100644 --- a/migration.c +++ b/migration.c @@ -279,19 +279,25 @@ static void migrate_fd_cleanup(MigrationState *s) notifier_list_notify(&migration_state_notifiers, s); } +static void migrate_finish_set_state(MigrationState *s, int new_state) +{ + if (__sync_val_compare_and_swap(&s->state, MIG_STATE_ACTIVE, + new_state) == new_state) { + trace_migrate_set_state(new_state); + } +} + void migrate_fd_error(MigrationState *s) { DPRINTF("setting error state\n"); - s->state = MIG_STATE_ERROR; - trace_migrate_set_state(MIG_STATE_ERROR); + migrate_finish_set_state(s, MIG_STATE_ERROR); migrate_fd_cleanup(s); } static void migrate_fd_completed(MigrationState *s) { DPRINTF("setting completed state\n"); - s->state = MIG_STATE_COMPLETED; - trace_migrate_set_state(MIG_STATE_COMPLETED); + migrate_finish_set_state(s, MIG_STATE_COMPLETED); migrate_fd_cleanup(s); } @@ -316,13 +322,9 @@ static ssize_t migrate_fd_put_buffer(MigrationState *s, const void *data, static void migrate_fd_cancel(MigrationState *s) { - if (s->state != MIG_STATE_ACTIVE) - return; - DPRINTF("cancelling migration\n"); - s->state = MIG_STATE_CANCELLED; - trace_migrate_set_state(MIG_STATE_CANCELLED); + migrate_finish_set_state(s, MIG_STATE_CANCELLED); migrate_fd_cleanup(s); } @@ -657,12 +659,14 @@ static void *buffered_file_thread(void *opaque) qemu_mutex_lock_iothread(); DPRINTF("beginning savevm\n"); qemu_savevm_state_begin(s->file, &s->params); + qemu_mutex_unlock_iothread(); while (s->state == MIG_STATE_ACTIVE) { int64_t current_time; uint64_t pending_size; if (s->bytes_xfer < s->xfer_limit) { + qemu_mutex_lock_iothread(); DPRINTF("iterate\n"); pending_size = qemu_savevm_state_pending(s->file, max_size); DPRINTF("pending size %lu max %lu\n", pending_size, max_size); @@ -678,8 +682,9 @@ static void *buffered_file_thread(void *opaque) qemu_savevm_state_complete(s->file); last_round = true; } + qemu_mutex_unlock_iothread(); } - qemu_mutex_unlock_iothread(); + current_time = qemu_get_clock_ms(rt_clock); if (current_time >= initial_time + BUFFER_DELAY) { uint64_t transferred_bytes = s->bytes_xfer; @@ -706,14 +711,18 @@ static void *buffered_file_thread(void *opaque) sleep_time += qemu_get_clock_ms(rt_clock) - current_time; } buffered_flush(s); - qemu_mutex_lock_iothread(); if (qemu_file_get_error(s->file)) { + qemu_mutex_lock_iothread(); migrate_fd_error(s); + qemu_mutex_unlock_iothread(); } else if (last_round && s->buffer_size == 0) { + qemu_mutex_lock_iothread(); migrate_fd_completed(s); + qemu_mutex_unlock_iothread(); } } + qemu_mutex_lock_iothread(); if (s->state == MIG_STATE_COMPLETED) { int64_t end_time = qemu_get_clock_ms(rt_clock); s->total_time = end_time - s->total_time; @@ -725,8 +734,8 @@ static void *buffered_file_thread(void *opaque) vm_start(); } } - qemu_mutex_unlock_iothread(); + g_free(s->buffer); return NULL; }