Commit d97326ee authored by Dr. David Alan Gilbert's avatar Dr. David Alan Gilbert Committed by Juan Quintela

Init the XBZRLE.lock in ram_mig_init

Initialising the XBZRLE.lock earlier simplifies the lock use.

Based on Markus's patch in:
http://lists.gnu.org/archive/html/qemu-devel/2014-03/msg03879.htmlSigned-off-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: default avatarGonglei <arei.gonglei@huawei.com>
Reviewed-by: default avatarMarkus Armbruster <armbru@redhat.com>
Signed-off-by: default avatarJuan Quintela <quintela@redhat.com>
parent 0d6ab3ab
......@@ -45,6 +45,7 @@
#include "hw/audio/pcspk.h"
#include "migration/page_cache.h"
#include "qemu/config-file.h"
#include "qemu/error-report.h"
#include "qmp-commands.h"
#include "trace.h"
#include "exec/cpu-all.h"
......@@ -167,11 +168,8 @@ static struct {
/* Cache for XBZRLE, Protected by lock. */
PageCache *cache;
QemuMutex lock;
} XBZRLE = {
.encoded_buf = NULL,
.current_buf = NULL,
.cache = NULL,
};
} XBZRLE;
/* buffer used for XBZRLE decoding */
static uint8_t *xbzrle_decoded_buf;
......@@ -187,41 +185,44 @@ static void XBZRLE_cache_unlock(void)
qemu_mutex_unlock(&XBZRLE.lock);
}
/*
* called from qmp_migrate_set_cache_size in main thread, possibly while
* a migration is in progress.
* A running migration maybe using the cache and might finish during this
* call, hence changes to the cache are protected by XBZRLE.lock().
*/
int64_t xbzrle_cache_resize(int64_t new_size)
{
PageCache *new_cache, *cache_to_free;
PageCache *new_cache;
int64_t ret;
if (new_size < TARGET_PAGE_SIZE) {
return -1;
}
/* no need to lock, the current thread holds qemu big lock */
XBZRLE_cache_lock();
if (XBZRLE.cache != NULL) {
/* check XBZRLE.cache again later */
if (pow2floor(new_size) == migrate_xbzrle_cache_size()) {
return pow2floor(new_size);
goto out_new_size;
}
new_cache = cache_init(new_size / TARGET_PAGE_SIZE,
TARGET_PAGE_SIZE);
if (!new_cache) {
DPRINTF("Error creating cache\n");
return -1;
}
XBZRLE_cache_lock();
/* the XBZRLE.cache may have be destroyed, check it again */
if (XBZRLE.cache != NULL) {
cache_to_free = XBZRLE.cache;
XBZRLE.cache = new_cache;
} else {
cache_to_free = new_cache;
error_report("Error creating cache");
ret = -1;
goto out;
}
XBZRLE_cache_unlock();
cache_fini(cache_to_free);
cache_fini(XBZRLE.cache);
XBZRLE.cache = new_cache;
}
return pow2floor(new_size);
out_new_size:
ret = pow2floor(new_size);
out:
XBZRLE_cache_unlock();
return ret;
}
/* accounting for migration statistics */
......@@ -732,28 +733,27 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
dirty_rate_high_cnt = 0;
if (migrate_use_xbzrle()) {
qemu_mutex_lock_iothread();
XBZRLE_cache_lock();
XBZRLE.cache = cache_init(migrate_xbzrle_cache_size() /
TARGET_PAGE_SIZE,
TARGET_PAGE_SIZE);
if (!XBZRLE.cache) {
qemu_mutex_unlock_iothread();
DPRINTF("Error creating cache\n");
XBZRLE_cache_unlock();
error_report("Error creating cache");
return -1;
}
qemu_mutex_init(&XBZRLE.lock);
qemu_mutex_unlock_iothread();
XBZRLE_cache_unlock();
/* We prefer not to abort if there is no memory */
XBZRLE.encoded_buf = g_try_malloc0(TARGET_PAGE_SIZE);
if (!XBZRLE.encoded_buf) {
DPRINTF("Error allocating encoded_buf\n");
error_report("Error allocating encoded_buf");
return -1;
}
XBZRLE.current_buf = g_try_malloc(TARGET_PAGE_SIZE);
if (!XBZRLE.current_buf) {
DPRINTF("Error allocating current_buf\n");
error_report("Error allocating current_buf");
g_free(XBZRLE.encoded_buf);
XBZRLE.encoded_buf = NULL;
return -1;
......@@ -1119,6 +1119,7 @@ static SaveVMHandlers savevm_ram_handlers = {
void ram_mig_init(void)
{
qemu_mutex_init(&XBZRLE.lock);
register_savevm_live(NULL, "ram", 0, 4, &savevm_ram_handlers, NULL);
}
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment