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From: Juan Quintela <quintela@redhat.com>
To: qemu-devel@nongnu.org
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>,
	Juan Quintela <quintela@redhat.com>,
	Laurent Vivier <lvivier@redhat.com>,
	kvm@vger.kernel.org, Thomas Huth <thuth@redhat.com>,
	Richard Henderson <rth@twiddle.net>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Wei Yang <richardw.yang@linux.intel.com>
Subject: [PULL 04/19] migration/multifd: call multifd_send_sync_main when sending RAM_SAVE_FLAG_EOS
Date: Thu, 11 Jul 2019 12:43:57 +0200
Message-ID: <20190711104412.31233-5-quintela@redhat.com> (raw)
In-Reply-To: <20190711104412.31233-1-quintela@redhat.com>

From: Wei Yang <richardw.yang@linux.intel.com>

On receiving RAM_SAVE_FLAG_EOS, multifd_recv_sync_main() is called to
synchronize receive threads. Current synchronization mechanism is to wait
for each channel's sem_sync semaphore. This semaphore is triggered by a
packet with MULTIFD_FLAG_SYNC flag. While in current implementation, we
don't do multifd_send_sync_main() to send such packet when
blk_mig_bulk_active() is true.

This will leads to the receive threads won't notify
multifd_recv_sync_main() by sem_sync. And multifd_recv_sync_main() will
always wait there.

[Note]: normal migration test works, while didn't test the
blk_mig_bulk_active() case. Since not sure how to produce this
situation.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20190612014337.11255-1-richardw.yang@linux.intel.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 migration/ram.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/migration/ram.c b/migration/ram.c
index 908517fc2b..74c9306c78 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -3466,8 +3466,8 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
      */
     ram_control_after_iterate(f, RAM_CONTROL_ROUND);
 
-    multifd_send_sync_main();
 out:
+    multifd_send_sync_main();
     qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
     qemu_fflush(f);
     ram_counters.transferred += 8;
-- 
2.21.0


  parent reply index

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-11 10:43 [PULL 00/19] Migration patches Juan Quintela
2019-07-11 10:43 ` [PULL 01/19] migration: fix multifd_recv event typo Juan Quintela
2019-07-11 10:43 ` [PULL 02/19] migration-test: rename parameter to parameter_int Juan Quintela
2019-07-11 10:43 ` [PULL 03/19] migration-test: Add migration multifd test Juan Quintela
2019-07-11 10:43 ` Juan Quintela [this message]
2019-07-11 10:43 ` [PULL 05/19] migration/xbzrle: update cache and current_data in one place Juan Quintela
2019-07-11 10:43 ` [PULL 06/19] cutils: remove one unnecessary pointer operation Juan Quintela
2019-07-11 10:44 ` [PULL 07/19] migration/multifd: sync packet_num after all thread are done Juan Quintela
2019-07-11 10:44 ` [PULL 08/19] migratioin/ram.c: reset complete_round when we gets a queued page Juan Quintela
2019-07-11 10:44 ` [PULL 09/19] migration: No need to take rcu during sync_dirty_bitmap Juan Quintela
2019-07-11 10:44 ` [PULL 10/19] memory: Don't set migration bitmap when without migration Juan Quintela
2019-07-11 10:44 ` [PULL 11/19] bitmap: Add bitmap_copy_with_{src|dst}_offset() Juan Quintela
2019-07-11 10:44 ` [PULL 12/19] memory: Pass mr into snapshot_and_clear_dirty Juan Quintela
2019-07-11 10:44 ` [PULL 13/19] memory: Introduce memory listener hook log_clear() Juan Quintela
2019-07-11 10:44 ` [PULL 14/19] kvm: Update comments for sync_dirty_bitmap Juan Quintela
2019-07-11 10:44 ` [PULL 15/19] kvm: Persistent per kvmslot dirty bitmap Juan Quintela
2019-07-11 10:44 ` [PULL 16/19] kvm: Introduce slots lock for memory listener Juan Quintela
2019-07-11 10:44 ` [PULL 17/19] kvm: Support KVM_CLEAR_DIRTY_LOG Juan Quintela
2019-07-11 10:44 ` [PULL 19/19] migration: allow private destination ram with x-ignore-shared Juan Quintela
2019-07-11 11:19 ` [PULL 00/19] Migration patches Paolo Bonzini
2019-07-11 11:32   ` Juan Quintela
2019-07-11 11:34   ` Dr. David Alan Gilbert
2019-07-11 11:40     ` [Qemu-devel] " Peter Maydell
2019-07-11 12:39 ` Peter Maydell
2019-07-12 14:06   ` Juan Quintela
2019-07-11 12:55 ` Christian Borntraeger
2019-07-11 13:01   ` [Qemu-devel] " Peter Maydell
2019-07-11 13:00 ` no-reply
2019-07-12 14:33 ` no-reply
2019-07-12 14:31 Juan Quintela
2019-07-12 14:31 ` [PULL 04/19] migration/multifd: call multifd_send_sync_main when sending RAM_SAVE_FLAG_EOS Juan Quintela

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