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author | Keir Fraser <keir@xen.org> | 2011-03-05 11:36:21 +0000 |
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committer | Keir Fraser <keir@xen.org> | 2011-03-05 11:36:21 +0000 |
commit | e00d02009db149c6b9ee52da9d0907e9fe362a23 (patch) | |
tree | bf883ef26aa6e3e475850cab78c1256c4b2b5a9a /xen/common/sched_credit.c | |
parent | 87fe7478aa597f8b9b744d19e3b79a64f3d9cf15 (diff) | |
download | xen-e00d02009db149c6b9ee52da9d0907e9fe362a23.tar.gz xen-e00d02009db149c6b9ee52da9d0907e9fe362a23.tar.bz2 xen-e00d02009db149c6b9ee52da9d0907e9fe362a23.zip |
sched_credit: Hold lock while dump scheduler info
Dump runq with debug key 'r' may cause dead loop like below:
(XEN) active vcpus:
(XEN) 1: [1.0] pri=0 flags=0 cpu=0 credit=263 [w=256]
(XEN) 2: [0.2] pri=0 flags=0 cpu=5 credit=284 [w=256]
(XEN) 3: [0.2] pri=0 flags=0 cpu=5 credit=282 [w=256]
...
(XEN) xxxxx: [0.2] pri=0 flags=0 cpu=2 credit=54 [w=256]
...
(XEN) xxxxx: [0.2] pri=0 flags=0 cpu=3 credit=-48 [w=256]
...
This means the active vcpu 0.2 became non-active with the active list
element empty just after it was accessed in the loop '2:'.
We should always hold a lock before access scheduler related list,
even in the debug purpose dump code.
Signed-off-by: Wei Gang <gang.wei@intel.com>
Diffstat (limited to 'xen/common/sched_credit.c')
-rw-r--r-- | xen/common/sched_credit.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/xen/common/sched_credit.c b/xen/common/sched_credit.c index d4852fd707..0cbc7e1342 100644 --- a/xen/common/sched_credit.c +++ b/xen/common/sched_credit.c @@ -1452,6 +1452,10 @@ csched_dump(const struct scheduler *ops) struct list_head *iter_sdom, *iter_svc; struct csched_private *prv = CSCHED_PRIV(ops); int loop; + unsigned long flags; + + spin_lock_irqsave(&(prv->lock), flags); + #define idlers_buf keyhandler_scratch printk("info:\n" @@ -1500,6 +1504,8 @@ csched_dump(const struct scheduler *ops) } } #undef idlers_buf + + spin_unlock_irqrestore(&(prv->lock), flags); } static int |