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[Qemu-devel] [PATCH 13/41] migration: prepare to access s->state outside
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PATCH 13/41] migration: prepare to access s->state outside critical sections |
Date: |
Fri, 15 Feb 2013 18:46:45 +0100 |
Accessing s->state outside the big QEMU lock will simplify a bit the
locking/unlocking of the iothread lock.
Signed-off-by: Paolo Bonzini <address@hidden>
---
migration.c | 21 ++++++++++++---------
1 files changed, 12 insertions(+), 9 deletions(-)
diff --git a/migration.c b/migration.c
index b0b5578..a7f619b 100644
--- a/migration.c
+++ b/migration.c
@@ -281,14 +281,14 @@ static void migrate_fd_cleanup(MigrationState *s)
void migrate_fd_error(MigrationState *s)
{
DPRINTF("setting error state\n");
- s->state = MIG_STATE_ERROR;
+ __sync_val_compare_and_swap(&s->state, MIG_STATE_ACTIVE, MIG_STATE_ERROR);
migrate_fd_cleanup(s);
}
static void migrate_fd_completed(MigrationState *s)
{
DPRINTF("setting completed state\n");
- s->state = MIG_STATE_COMPLETED;
+ __sync_val_compare_and_swap(&s->state, MIG_STATE_ACTIVE,
MIG_STATE_COMPLETED);
migrate_fd_cleanup(s);
}
@@ -313,12 +313,9 @@ 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;
+ __sync_val_compare_and_swap(&s->state, MIG_STATE_ACTIVE,
MIG_STATE_CANCELLED);
migrate_fd_cleanup(s);
}
@@ -651,12 +648,14 @@ 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 = qemu_get_clock_ms(rt_clock);
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);
@@ -672,8 +671,8 @@ static void *buffered_file_thread(void *opaque)
qemu_savevm_state_complete(s->file);
last_round = true;
}
+ qemu_mutex_unlock_iothread();
}
- qemu_mutex_unlock_iothread();
if (current_time >= initial_time + BUFFER_DELAY) {
uint64_t transferred_bytes = s->bytes_xfer;
uint64_t time_spent = current_time - initial_time;
@@ -692,14 +691,18 @@ static void *buffered_file_thread(void *opaque)
g_usleep((initial_time + BUFFER_DELAY - current_time)*1000);
}
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;
@@ -711,8 +714,8 @@ static void *buffered_file_thread(void *opaque)
vm_start();
}
}
-
qemu_mutex_unlock_iothread();
+
g_free(s->buffer);
return NULL;
}
--
1.7.1
- Re: [Qemu-devel] [PATCH 31/41] qemu-file: check exit status when closing a pipe QEMUFile, (continued)
- [Qemu-devel] [PATCH 39/41] migration: move contents of migration_close to migrate_fd_cleanup, Paolo Bonzini, 2013/02/15
- [Qemu-devel] [PATCH 36/41] migration: use qemu_ftell to compute bandwidth, Paolo Bonzini, 2013/02/15
- [Qemu-devel] [PATCH 38/41] migration: move rate limiting to QEMUFile, Paolo Bonzini, 2013/02/15
- [Qemu-devel] [PATCH 41/41] migration: inline migrate_fd_close, Paolo Bonzini, 2013/02/15
- [Qemu-devel] [PATCH 40/41] migration: eliminate s->migration_file, Paolo Bonzini, 2013/02/15
- [Qemu-devel] [PATCH 17/41] block-migration: document usage of state across threads, Paolo Bonzini, 2013/02/15
- [Qemu-devel] [PATCH 13/41] migration: prepare to access s->state outside critical sections,
Paolo Bonzini <=
- [Qemu-devel] [PATCH 16/41] block-migration: small preparatory changes for locking, Paolo Bonzini, 2013/02/15
- [Qemu-devel] [PATCH 19/41] migration: reorder SaveVMHandlers members, Paolo Bonzini, 2013/02/15