[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 1/4] VT-d/qinval: make local variable used for communication with IOMMU "volatile"
Jan Beulich wrote on 2014-06-16: > Without that there is - afaict - nothing preventing the compiler from > putting the variable into a register for the duration of the wait loop. > > Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx> Acked-by: Yang Zhang <yang.z.zhang@xxxxxxxxx> > > --- a/xen/drivers/passthrough/vtd/qinval.c > +++ b/xen/drivers/passthrough/vtd/qinval.c > @@ -196,7 +196,7 @@ static int queue_invalidate_wait(struct > u8 iflag, u8 sw, u8 fn) { s_time_t start_time; > - u32 poll_slot = QINVAL_STAT_INIT; > + volatile u32 poll_slot = QINVAL_STAT_INIT; > int index = -1; > int ret = -1; > unsigned long flags; > Best regards, Yang _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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