diff options
Diffstat (limited to 'migration')
-rw-r--r-- | migration/ram.c | 45 |
1 files changed, 28 insertions, 17 deletions
diff --git a/migration/ram.c b/migration/ram.c index 58adcaf430..eb9db4f777 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -355,6 +355,12 @@ static RAMState *ram_state; static NotifierWithReturnList precopy_notifier_list; +/* Whether postcopy has queued requests? */ +static bool postcopy_has_request(RAMState *rs) +{ + return !QSIMPLEQ_EMPTY_ATOMIC(&rs->src_page_requests); +} + void precopy_infrastructure_init(void) { notifier_with_return_list_init(&precopy_notifier_list); @@ -1539,28 +1545,33 @@ static bool find_dirty_block(RAMState *rs, PageSearchStatus *pss, bool *again) */ static RAMBlock *unqueue_page(RAMState *rs, ram_addr_t *offset) { + struct RAMSrcPageRequest *entry; RAMBlock *block = NULL; - if (QSIMPLEQ_EMPTY_ATOMIC(&rs->src_page_requests)) { + if (!postcopy_has_request(rs)) { return NULL; } QEMU_LOCK_GUARD(&rs->src_page_req_mutex); - if (!QSIMPLEQ_EMPTY(&rs->src_page_requests)) { - struct RAMSrcPageRequest *entry = - QSIMPLEQ_FIRST(&rs->src_page_requests); - block = entry->rb; - *offset = entry->offset; - - if (entry->len > TARGET_PAGE_SIZE) { - entry->len -= TARGET_PAGE_SIZE; - entry->offset += TARGET_PAGE_SIZE; - } else { - memory_region_unref(block->mr); - QSIMPLEQ_REMOVE_HEAD(&rs->src_page_requests, next_req); - g_free(entry); - migration_consume_urgent_request(); - } + + /* + * This should _never_ change even after we take the lock, because no one + * should be taking anything off the request list other than us. + */ + assert(postcopy_has_request(rs)); + + entry = QSIMPLEQ_FIRST(&rs->src_page_requests); + block = entry->rb; + *offset = entry->offset; + + if (entry->len > TARGET_PAGE_SIZE) { + entry->len -= TARGET_PAGE_SIZE; + entry->offset += TARGET_PAGE_SIZE; + } else { + memory_region_unref(block->mr); + QSIMPLEQ_REMOVE_HEAD(&rs->src_page_requests, next_req); + g_free(entry); + migration_consume_urgent_request(); } return block; @@ -2992,7 +3003,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaque) t0 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); i = 0; while ((ret = qemu_file_rate_limit(f)) == 0 || - !QSIMPLEQ_EMPTY(&rs->src_page_requests)) { + postcopy_has_request(rs)) { int pages; if (qemu_file_get_error(f)) { |