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[PATCH 4/5] migration: Make find_dirty_block() return a single parameter
From: |
Juan Quintela |
Subject: |
[PATCH 4/5] migration: Make find_dirty_block() return a single parameter |
Date: |
Tue, 21 Jun 2022 16:05:06 +0200 |
We used to return two bools, just return a single int with the
following meaning:
old return / again / new return
false false 0
false true 1
true true 2 /* We don't care about again at all */
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
migration/ram.c | 37 +++++++++++++++++++------------------
1 file changed, 19 insertions(+), 18 deletions(-)
diff --git a/migration/ram.c b/migration/ram.c
index 1d4ff3185b..2c7289edad 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1481,13 +1481,16 @@ retry:
* find_dirty_block: find the next dirty page and update any state
* associated with the search process.
*
- * Returns true if a page is found
+ * Returns:
+ * 0: no page found, give up
+ * 1: no page found, retry
+ * 2: page found
*
* @rs: current RAM state
* @pss: data about the state of the current dirty page scan
* @again: set to false if the search has scanned the whole of RAM
*/
-static bool find_dirty_block(RAMState *rs, PageSearchStatus *pss, bool *again)
+static int find_dirty_block(RAMState *rs, PageSearchStatus *pss)
{
/* This is not a postcopy requested page */
pss->postcopy_requested = false;
@@ -1499,8 +1502,7 @@ static bool find_dirty_block(RAMState *rs,
PageSearchStatus *pss, bool *again)
* We've been once around the RAM and haven't found anything.
* Give up.
*/
- *again = false;
- return false;
+ return 0;
}
if (!offset_in_ramblock(pss->block,
((ram_addr_t)pss->page) << TARGET_PAGE_BITS)) {
@@ -1529,13 +1531,10 @@ static bool find_dirty_block(RAMState *rs,
PageSearchStatus *pss, bool *again)
}
}
/* Didn't find anything this time, but try again on the new block */
- *again = true;
- return false;
+ return 1;
} else {
- /* Can go around again, but... */
- *again = true;
- /* We've found something so probably don't need to */
- return true;
+ /* We've found something */
+ return 2;
}
}
@@ -2270,18 +2269,20 @@ static int ram_find_and_save_block(RAMState *rs)
pss.block = QLIST_FIRST_RCU(&ram_list.blocks);
}
- do {
+ while (true){
if (!get_queued_page(rs, &pss)) {
/* priority queue empty, so just search for something dirty */
- bool again = true;
- if (!find_dirty_block(rs, &pss, &again)) {
- if (!again) {
- break;
- }
- }
+ int res = find_dirty_block(rs, &pss);
+ if (res == 0) {
+ break;
+ } else if (res == 1)
+ continue;
}
pages = ram_save_host_page(rs, &pss);
- } while (!pages);
+ if (pages) {
+ break;
+ }
+ }
rs->last_seen_block = pss.block;
rs->last_page = pss.page;
--
2.34.1