linux-kernel - [PATCH v1 2/2] virtio-balloon: improve update_balloon_size

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1546493462-32244-3-git-send-email-wei.w.wang@intel.com>
Date:   Thu,  3 Jan 2019 13:31:02 +0800
From:   Wei Wang <wei.w.wang@...el.com>
To:     virtio-dev@...ts.oasis-open.org, linux-kernel@...r.kernel.org,
        virtualization@...ts.linux-foundation.org, kvm@...r.kernel.org,
        mst@...hat.com, cohuck@...hat.com
Cc:     borntraeger@...ibm.com, pbonzini@...hat.com, dgilbert@...hat.com,
        wei.w.wang@...el.com, pasic@...ux.ibm.com
Subject: [PATCH v1 2/2] virtio-balloon: improve update_balloon_size_func

There is no need to update the balloon actual register when there is no
ballooning request. This patch avoids update_balloon_size when diff is 0.

Signed-off-by: Wei Wang <wei.w.wang@...el.com>
---
 drivers/virtio/virtio_balloon.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 9a82a11..4884b85 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -435,9 +435,12 @@ static void update_balloon_size_func(struct work_struct *work)
 			  update_balloon_size_work);
 	diff = towards_target(vb);
 
+	if (!diff)
+		return;
+
 	if (diff > 0)
 		diff -= fill_balloon(vb, diff);
-	else if (diff < 0)
+	else
 		diff += leak_balloon(vb, -diff);
 	update_balloon_size(vb);
 
-- 
2.7.4