xen-devel.lists.xenproject.org archive mirror
 help / color / mirror / Atom feed
* [PATCH v4] xen: sched: fix deadlock when changing scheduling parameters
@ 2016-04-05 22:22 Chong Li
  0 siblings, 0 replies; only message in thread
From: Chong Li @ 2016-04-05 22:22 UTC (permalink / raw)
  To: xen-devel
  Cc: Chong Li, george.dunlap, dario.faggioli, mengxu, jbeulich,
	lichong659, dgolomb

Commit f7b87b0745b4 ("enable per-VCPU parameter for RTDS") introduced
a bug: it made it possible, in Credit and Credit2, when doing domain
or vcpu parameters' manipulation, to leave the hypervisor with a
spinlock held and interrupts disabled.

Fix it.

Signed-off-by: Chong Li <chong.li@wustl.edu>

Acked-by: Dario Faggioli <dario.faggioli@citrix.com>
---
CC: <dario.faggioli@citrix.com>
CC: <george.dunlap@eu.citrix.com>
CC: <dgolomb@seas.upenn.edu>
CC: <mengxu@cis.upenn.edu>
CC: <jbeulich@suse.com>
CC: <lichong659@gmail.com>
---
 xen/common/sched_credit.c  | 6 ++++--
 xen/common/sched_credit2.c | 6 ++++--
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/xen/common/sched_credit.c b/xen/common/sched_credit.c
index e5d15d8..4c4927f 100644
--- a/xen/common/sched_credit.c
+++ b/xen/common/sched_credit.c
@@ -1075,6 +1075,7 @@ csched_dom_cntl(
     struct csched_dom * const sdom = CSCHED_DOM(d);
     struct csched_private *prv = CSCHED_PRIV(ops);
     unsigned long flags;
+    int rc = 0;
 
     /* Protect both get and put branches with the pluggable scheduler
      * lock. Runq lock not needed anywhere in here. */
@@ -1101,12 +1102,13 @@ csched_dom_cntl(
             sdom->cap = op->u.credit.cap;
         break;
     default:
-        return -EINVAL;
+        rc = -EINVAL;
+        break;
     }
 
     spin_unlock_irqrestore(&prv->lock, flags);
 
-    return 0;
+    return rc;
 }
 
 static inline void
diff --git a/xen/common/sched_credit2.c b/xen/common/sched_credit2.c
index d48ed5a..b8c8e40 100644
--- a/xen/common/sched_credit2.c
+++ b/xen/common/sched_credit2.c
@@ -1416,6 +1416,7 @@ csched2_dom_cntl(
     struct csched2_dom * const sdom = CSCHED2_DOM(d);
     struct csched2_private *prv = CSCHED2_PRIV(ops);
     unsigned long flags;
+    int rc = 0;
 
     /* Must hold csched2_priv lock to read and update sdom,
      * runq lock to update csvcs. */
@@ -1457,12 +1458,13 @@ csched2_dom_cntl(
         }
         break;
     default:
-        return -EINVAL;
+        rc = -EINVAL;
+        break;
     }
 
     spin_unlock_irqrestore(&prv->lock, flags);
 
-    return 0;
+    return rc;
 }
 
 static void *
-- 
1.9.1


_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel

^ permalink raw reply	[flat|nested] only message in thread

only message in thread, other threads:[~2016-04-05 22:22 UTC | newest]

Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-04-05 22:22 [PATCH v4] xen: sched: fix deadlock when changing scheduling parameters Chong Li

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).