From: Eunbyung Park <silverbottlep@gmail.com>
To: george.dunlap@eu.citrix.com
Cc: xen-devel@lists.xensource.com
Subject: deadlock in the credit2
Date: Fri, 14 Oct 2011 18:08:58 +0900 [thread overview]
Message-ID: <4E97FC2A.8080004@gmail.com> (raw)
IMHO, it seems to be deadlock when changing dom0's weight in credit2
scheduler.
when the sched_adjust() in schedule.c is called, it grabs the
schedule_lock after pausing all of the vcpus
and then, csched_dom_cntl in sched_credit2.c, it also grab the
schedule_lock by using vcpu_schedule_lock_irq().
In the credit2, all of the percpu schedule_lock points out same runqueue
lock if they belong to same runqueue.
Eventually, all of vcpu are paused except for itself running the code,
and it try to grab schedule_lock that was grabbed by itself.
Am I right? If I was wrong, please tell me my misunderstanding.
And, I have a question about the code, where are in sched_adjust() in
schedule.c
if ( d == current->domain )
vcpu_schedule_lock_irq(current);
It was very hard to understan for me..:) What does it exactly mean?
I would be very grateful for any comments
--
Best Regards,
Eunbyung Park
next reply other threads:[~2011-10-14 9:08 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-14 9:08 Eunbyung Park [this message]
2011-10-14 11:47 ` deadlock in the credit2 George Dunlap
2011-10-14 12:11 ` Keir Fraser
2011-10-15 4:48 ` Eunbyung Park
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