Re: [PATCH 9/11] Panic delay fix

Dmitry Torokhov
2007-02-08T14:43:59Z

On 2/7/07, Rusty Russell <rusty@rustcorp.com.au> wrote:
> On Wed, 2007-02-07 at 12:35 +0000, Pavel Machek wrote:
> > Ugh, it sounds like paravirt is more b0rken then I thought. It should
> > always to the proper delay, then replace those udelays that are not
> > needed on virtualized hardware with something else.
> >
> > Just magically defining udelay into nop is broken.
>
> We'd have to audit and figure out what udelays are for hardware and
> which are not, but the evidence is that the vast majority of them are
> for hardware and not needed for virtualization.
>
> Changing udelay to "hardware_udelay" or something all over the kernel
> would have delayed the paravirt_ops merge by an infinite amount 8)
>

However I am not really fond of idea of adding constructs like this
all over the code:

#define USE_REAL_TIME_DELAY_I_REALLY_MEAN_IT_THIS_TIME_I_SWEAR

as the time passes... Drivers should be blissfully ignorant of being
run on virtual hardware.

--
Dmitry