lkml.org 
[lkml]   [2004]   [Dec]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: RCU question
Zwane Mwaikambo wrote:

>On Fri, 10 Dec 2004, George Anzinger wrote:
>
>
>
>>That is ok. Either we have interrupts off and no softirqs are pending and we
>>proceed to the "hlt" (where the interrupt will be taken), or softirqs are
>>pending, we turn interrupts on, do the softirq, turn interrupts off and try
>>again. Unless some tasklet (RCU?) never "gives up" or we will exit the while
>>with interrupts off and move on to the "hlt". Or did I miss something?
>>
>>
>
>But the point is that you cannot execute hlt with interrupts disabled.
>
>
The trick is the sti instruction: It enables interrupt processing after
the following instruction.

Thus
sti
hlt

cannot race - it atomically enables interrupts and waits.

--
Manfred

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

\
 
 \ /
  Last update: 2005-03-22 14:08    [W:0.230 / U:0.008 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site