| Message ID | 1397777399-5353-1-git-send-email-kamal@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 797e1c7..494e1f7 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -310,6 +310,12 @@ static int balloon(void *_vballoon) else if (diff < 0) leak_balloon(vb, -diff); update_balloon_size(vb); + + /* + * For large balloon changes, we could spend a lot of time + * and always have work to do. Be nice if preempt disabled. + */ + cond_resched(); } return 0; }
This is a note to let you know that I have just added a patch titled virtio_balloon: don't softlockup on huge balloon changes. to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue This patch is scheduled to be released in version 3.8.13.22. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.8.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 86c337ee6fd3e09c8202d4a855eb1d74c43d32a8 Mon Sep 17 00:00:00 2001 From: Rusty Russell <rusty@rustcorp.com.au> Date: Thu, 13 Mar 2014 11:23:38 +1030 Subject: virtio_balloon: don't softlockup on huge balloon changes. commit 1f74ef0f2d7d692fcd615621e0e734c3e7771413 upstream. When adding or removing 100G from a balloon: BUG: soft lockup - CPU#0 stuck for 22s! [vballoon:367] We have a wait_event_interruptible(), but the condition is always true (more ballooning to do) so we don't ever sleep. We also have a wait_event() for the host to ack, but that is also always true as QEMU is synchronous for balloon operations. Reported-by: Gopesh Kumar Chaudhary <gopchaud@in.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/virtio/virtio_balloon.c | 6 ++++++ 1 file changed, 6 insertions(+) -- 1.9.1