[v1] Migration staging patches

[PULL 06/11] migration: Don't sync volatile memory after migration completes

Peter Xu posted 11 patches 4 months, 3 weeks ago

Diff against v1
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Maintainers: Paolo Bonzini <pbonzini@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>, David Hildenbrand <david@redhat.com>, Peter Xu <peterx@redhat.com>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Steve Sistare <steven.sistare@oracle.com>, Fabiano Rosas <farosas@suse.de>, Laurent Vivier <lvivier@redhat.com>, "Marc-André Lureau" <marcandre.lureau@redhat.com>

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[PULL 06/11] migration: Don't sync volatile memory after migration completes

Posted by Peter Xu 4 months, 3 weeks ago

From: "Chaney, Ben" <bchaney@akamai.com>

Syncing volatile memory provides no benefit, instead it can cause
performance issues in some cases.  Only sync memory that is marked as
non-volatile after migration completes on destination.

Signed-off-by: Ben Chaney <bchaney@akamai.com>
Fixes: bd108a44bc29 (migration: ram: Switch to ram block writeback)
Link: https://lore.kernel.org/r/1CC43F59-336F-4A12-84AD-DB89E0A17A95@akamai.com
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 migration/ram.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/migration/ram.c b/migration/ram.c
index fd8d83b63c..024d8b3d03 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -3680,7 +3680,9 @@ static int ram_load_cleanup(void *opaque)
     RAMBlock *rb;
 
     RAMBLOCK_FOREACH_NOT_IGNORED(rb) {
-        qemu_ram_block_writeback(rb);
+        if (memory_region_is_nonvolatile(rb->mr)) {
+            qemu_ram_block_writeback(rb);
+        }
     }
 
     xbzrle_load_cleanup();
-- 
2.49.0