Re: wake_up() from interrupt - on the next jiffie?

From: gl
Date: Tue Jul 05 2005 - 09:34:46 EST


Solved (below).

On Mon, 4 Jul 2005 gl@xxxxxxxxx wrote:

> This might well be my basic misunderstanding, or the test was wrong, but
> the probability is pretty low, so, asking here.
>
> I thought, if a task sleeps on, say, read() and then data come and there's
> no other runnable task with a higher priority, the sleeping task should be
> woken up immediately. My test showed that the task is only woken up on the
> next jiffie. Kernel 2.6.11.10.
>
> Details: a program does a cfmakeraw() on a ttyS, and does blocking reads

setserial low_latency solves the problem. Thanks for not answering:-)

Thanks
Guennadi
---------------------------------
Guennadi Liakhovetski, Ph.D.
DSA Daten- und Systemtechnik GmbH
Pascalstr. 28
D-52076 Aachen
Germany
-
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/