On Thu, Sep 11, 2014 at 11:38:38AM +0530, Amit Shah wrote:
> On (Wed) 10 Sep 2014 [17:07:07], Amos Kong wrote:
> > When I check hwrng attributes in sysfs, cat process always gets
> > stuck if guest has only 1 vcpu and uses a slow rng backend.
> >
> > Currently we check if there is any tasks waiting to be run on
> > current cpu in rng_dev_read() by need_resched(). But need_resched()
> > doesn't work because rng_dev_read() is executing in user context.
> >
> > This patch removed need_resched() and increase delay to 10 jiffies,
> > then other tasks can have chance to execute protected code.
> > Delaying 1 jiffy also works, but 10 jiffies is safer.
Hi Amit,
> I'd prefer two patches for this one: one to remove the need_resched()
> check, and the other to increase the timeout.
If Rusty agrees with this fix, I will respin to update the commitlog
with clear description and split the patches to 3.
Thanks for the review.
> Anyway,
>
> Reviewed-by: Amit Shah <amit.shah@xxxxxxxxxx>
--
Amos.
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