[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH v9 46/56] Don't sync dirty bitmaps in postcopy
From: |
Dr. David Alan Gilbert (git) |
Subject: |
[Qemu-devel] [PATCH v9 46/56] Don't sync dirty bitmaps in postcopy |
Date: |
Thu, 5 Nov 2015 18:11:13 +0000 |
From: "Dr. David Alan Gilbert" <address@hidden>
Once we're in postcopy the source processors are stopped and memory
shouldn't change any more, so there's no need to look at the dirty
map.
There are two notes to this:
1) If we do resync and a page had changed then the page would get
sent again, which the destination wouldn't allow (since it might
have also modified the page)
2) Before disabling this I'd seen very rare cases where a page had been
marked dirtied although the memory contents are apparently identical
Signed-off-by: Dr. David Alan Gilbert <address@hidden>
Reviewed-by: David Gibson <address@hidden>
Reviewed-by: Juan Quintela <address@hidden>
Reviewed-by: Amit Shah <address@hidden>
---
migration/ram.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/migration/ram.c b/migration/ram.c
index 8bf0841..339b001 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1846,7 +1846,9 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
{
rcu_read_lock();
- migration_bitmap_sync();
+ if (!migration_in_postcopy(migrate_get_current())) {
+ migration_bitmap_sync();
+ }
ram_control_before_iterate(f, RAM_CONTROL_FINISH);
@@ -1881,7 +1883,8 @@ static void ram_save_pending(QEMUFile *f, void *opaque,
uint64_t max_size,
remaining_size = ram_save_remaining() * TARGET_PAGE_SIZE;
- if (remaining_size < max_size) {
+ if (!migration_in_postcopy(migrate_get_current()) &&
+ remaining_size < max_size) {
qemu_mutex_lock_iothread();
rcu_read_lock();
migration_bitmap_sync();
--
2.5.0
- [Qemu-devel] [PATCH v9 38/56] Postcopy: Postcopy startup in migration thread, (continued)
- [Qemu-devel] [PATCH v9 38/56] Postcopy: Postcopy startup in migration thread, Dr. David Alan Gilbert (git), 2015/11/05
- [Qemu-devel] [PATCH v9 40/56] Page request: Add MIG_RP_MSG_REQ_PAGES reverse command, Dr. David Alan Gilbert (git), 2015/11/05
- [Qemu-devel] [PATCH v9 39/56] Postcopy: End of iteration, Dr. David Alan Gilbert (git), 2015/11/05
- [Qemu-devel] [PATCH v9 41/56] Page request: Process incoming page request, Dr. David Alan Gilbert (git), 2015/11/05
- [Qemu-devel] [PATCH v9 42/56] Page request: Consume pages off the post-copy queue, Dr. David Alan Gilbert (git), 2015/11/05
- [Qemu-devel] [PATCH v9 44/56] Postcopy: Use helpers to map pages during migration, Dr. David Alan Gilbert (git), 2015/11/05
- [Qemu-devel] [PATCH v9 43/56] postcopy_ram.c: place_page and helpers, Dr. David Alan Gilbert (git), 2015/11/05
- [Qemu-devel] [PATCH v9 45/56] postcopy: Check order of received target pages, Dr. David Alan Gilbert (git), 2015/11/05
- [Qemu-devel] [PATCH v9 46/56] Don't sync dirty bitmaps in postcopy,
Dr. David Alan Gilbert (git) <=
- [Qemu-devel] [PATCH v9 47/56] Don't iterate on precopy-only devices during postcopy, Dr. David Alan Gilbert (git), 2015/11/05
- [Qemu-devel] [PATCH v9 48/56] Host page!=target page: Cleanup bitmaps, Dr. David Alan Gilbert (git), 2015/11/05
- [Qemu-devel] [PATCH v9 49/56] Round up RAMBlock sizes to host page sizes, Dr. David Alan Gilbert (git), 2015/11/05
- [Qemu-devel] [PATCH v9 50/56] Postcopy; Handle userfault requests, Dr. David Alan Gilbert (git), 2015/11/05
- [Qemu-devel] [PATCH v9 51/56] Start up a postcopy/listener thread ready for incoming page data, Dr. David Alan Gilbert (git), 2015/11/05
- [Qemu-devel] [PATCH v9 52/56] postcopy: Wire up loadvm_postcopy_handle_ commands, Dr. David Alan Gilbert (git), 2015/11/05
- [Qemu-devel] [PATCH v9 53/56] Postcopy: Mark nohugepage before discard, Dr. David Alan Gilbert (git), 2015/11/05
- [Qemu-devel] [PATCH v9 54/56] End of migration for postcopy, Dr. David Alan Gilbert (git), 2015/11/05
- [Qemu-devel] [PATCH v9 55/56] Disable mlock around incoming postcopy, Dr. David Alan Gilbert (git), 2015/11/05