[PATCH v5] introduce macro spin_event_timeout()
Timur Tabi
timur at freescale.com
Wed Mar 11 11:22:28 EST 2009
On Tue, Mar 10, 2009 at 6:59 PM, Benjamin Herrenschmidt
<benh at kernel.crashing.org> wrote:
> And ? We can disagree with Alan...
If you guys want to argue with Alan on lkml, please go ahead. I could
use the support.
Alan did have one valid point though. Determining how long to loop
for is architecture-specific. Using jiffies is bad, because even one
jiffy is too long. Adding a udelay() inside the loop means that it
only checks he condition every microsecond. So the real solution is
to use keep looping until a certain amount of time has passed. This
means using an architecture-specific timebase register.
Now we can create a generic version of the function that uses jiffies,
and then arch-specific versions where possible. But Alan still needs
to be convinced. I already posted a length rebuttal to his email, but
I haven't gotten a reply yet.
--
Timur Tabi
Linux kernel developer at Freescale
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