Messages in this thread | | | Date | Thu, 23 Nov 2006 01:31:47 -0800 | From | "Paul Menage" <> | Subject | Re: [ckrm-tech] [PATCH 4/13] BC: context handling |
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On 11/23/06, Pavel Emelianov <xemul@openvz.org> wrote: > You mean moving is like this: > > old_bc = task->real_bc; > task->real_bc = new_bc; > cmpxchg(&tsk->exec_bc, old_bc, new_bc); > > ? Then this won't work: > > Initialisation: > current->exec_bc = init_bc; > current->real_bc = init_bc; > ... > IRQ: > current->exec_bc = init_bc; > ... > old_bc = tsk->real_bc; /* init_bc */ > tsk->real_bc = bc1; > cx(tsk->exec_bc, init_bc, bc1); /* ok */ > ... > Here at the middle of an interrupt > we have bc1 set as exec_bc on task > which IS wrong!
You could get round that by having a separate "irq_bc" that's never valid for a task not in an interrupt.
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