Re: [PATCH v4] introduce macro spin_event_timeout()

[Timur Tabi]

Grant Likely wrote:

> #define spin_until_timeout(condition, timeout, rc)          \
>       for (unsigned long __timeout = jiffies + (timeout);     \
>               (!(rc = (condition)) && time_after(jiffies, __timeout)); )

Ooo, that's good.

I'm still not crazy about using jiffies, since it doesn't get
incremented when interrupts are disabled, and I'd like this function to
work in those cases.  How about get_cycles()?  I know it's not supported
on all platforms, but I'm willing to live with that.

The other problem with get_cycles() is that there doesn't appear to be a
num_cycles_per_usec() function, so there's no way for me to scale the
count to a fixed time period.

-- 
Timur Tabi
Linux kernel developer at Freescale
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/