Re: [PATCH 9/11] Panic delay fix

Zachary Amsden
2007-02-07T22:23:52Z

Rusty Russell 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)
>

Yes, so I chose the same approach used for b0rken hardware - #define
REALLY_SLOW_IO before including headers. It's ugly, but it works
without rewriting the entire source base.

Zach