migration: Cleanup xbzrle zero page cache update logic

The major change is to replace "!save_page_use_compression()" with
"xbzrle_enabled" to make it clear.

Reasonings:

(1) When compression enabled, "!save_page_use_compression()" is exactly the
    same as checking "xbzrle_enabled".

(2) When compression disabled, "!save_page_use_compression()" always return
    true.  We used to try calling the xbzrle code, but after this change we
    won't, and we shouldn't need to.

Since at it, drop the xbzrle_enabled check in xbzrle_cache_zero_page()
because with this change it's not needed anymore.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
master
Peter Xu 2022-10-11 17:55:47 -04:00 committed by Juan Quintela
parent 20123ee1de
commit ef5c3d1391
1 changed files with 1 additions and 5 deletions

View File

@ -741,10 +741,6 @@ void mig_throttle_counter_reset(void)
*/
static void xbzrle_cache_zero_page(RAMState *rs, ram_addr_t current_addr)
{
if (!rs->xbzrle_enabled) {
return;
}
/* We don't care if this fails to allocate a new cache page
* as long as it updated an old one */
cache_insert(XBZRLE.cache, current_addr, XBZRLE.zero_target_page,
@ -2301,7 +2297,7 @@ static int ram_save_target_page(RAMState *rs, PageSearchStatus *pss)
/* Must let xbzrle know, otherwise a previous (now 0'd) cached
* page would be stale
*/
if (!save_page_use_compression(rs)) {
if (rs->xbzrle_enabled) {
XBZRLE_cache_lock();
xbzrle_cache_zero_page(rs, block->offset + offset);
XBZRLE_cache_unlock();