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From: George Anzinger <george@mvista.com>
To: Manfred Spraul <manfred@colorfullife.com>
Cc: Zwane Mwaikambo <zwane@arm.linux.org.uk>,
	Lee Revell <rlrevell@joe-job.com>,
	dipankar@in.ibm.com, ganzinger@mvista.com,
	lkml <linux-kernel@vger.kernel.org>
Subject: Re: RCU question
Date: Sat, 11 Dec 2004 08:52:02 -0800	[thread overview]
Message-ID: <41BB25B2.90303@mvista.com> (raw)
In-Reply-To: <41BB2108.70606@colorfullife.com>

Manfred Spraul wrote:
> 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.

Exactly :)

-- 
George Anzinger   george@mvista.com
High-res-timers:  http://sourceforge.net/projects/high-res-timers/


  reply	other threads:[~2004-12-11 16:52 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-12-09 23:59 RCU question George Anzinger
2004-12-10  4:31 ` Dipankar Sarma
2004-12-10 19:42   ` George Anzinger
2004-12-10 20:40     ` Dipankar Sarma
2004-12-10 20:45       ` Lee Revell
2004-12-10 21:02         ` George Anzinger
2004-12-10 22:58           ` Zwane Mwaikambo
2004-12-11  2:22             ` George Anzinger
2004-12-11  2:45               ` Zwane Mwaikambo
2004-12-11  3:29                 ` George Anzinger
2004-12-11 14:52                   ` Zwane Mwaikambo
2004-12-11 16:32                     ` Manfred Spraul
2004-12-11 16:52                       ` George Anzinger [this message]
2004-12-12  2:53                         ` Zwane Mwaikambo
2004-12-12  8:59                           ` Manfred Spraul
2004-12-12  9:37                             ` Andrea Arcangeli
2004-12-12 10:22                               ` Manfred Spraul
2004-12-12 12:15                                 ` Andrea Arcangeli
2004-12-14 21:40                                   ` Lee Revell
2004-12-14 22:23                                     ` [patch, 2.6.10-rc3] safe_hlt() & NMIs Ingo Molnar
2004-12-14 22:47                                       ` Ingo Molnar
2004-12-14 23:09                                         ` Linus Torvalds
2004-12-15  8:52                                           ` Ingo Molnar
2004-12-15 15:44                                             ` Linus Torvalds
2004-12-15 16:35                                               ` Ingo Molnar
2004-12-16  0:37                                           ` Alan Cox
2004-12-16  1:58                                             ` Linus Torvalds
2004-12-16 14:51                                               ` Ingo Molnar
2004-12-16 15:08                                                 ` Maciej W. Rozycki
2004-12-16 15:11                                                   ` Ingo Molnar
2004-12-16 15:42                                                     ` Maciej W. Rozycki
2004-12-16 15:54                                                 ` Linus Torvalds
2004-12-16  2:10                                             ` Zwane Mwaikambo
2004-12-16 13:26                                               ` Alan Cox
2004-12-14 23:41                                         ` Andrea Arcangeli
2004-12-14 23:00                                       ` Linus Torvalds
2004-12-15  5:04                                         ` Andi Kleen
2004-12-15  6:27                                       ` Avi Kivity
2004-12-15  8:51                                         ` Ingo Molnar
2004-12-12 16:51                                 ` RCU question George Anzinger
2004-12-12 22:40                                   ` Manfred Spraul
2004-12-13  5:22                                     ` George Anzinger
2004-12-12 16:26                             ` Zwane Mwaikambo
  -- strict thread matches above, loose matches on Subject: below --
2016-04-29 19:07 RCU Question siddharth teotia
     [not found] <CAJw6sH0=pZX__YaeMwozF673u3Dyn7Jzp3g9q2FuYurThO6paw@mail.gmail.com>
2016-04-29 19:10 ` siddharth teotia
     [not found] ` <CAJw6sH0kFFVvmWm2vRQ+KNTgJaKVXS47OCATY2zHTA0AiSipiQ@mail.gmail.com>
2016-05-02 20:53   ` Mathieu Desnoyers
     [not found]   ` <1208862117.75733.1462222380579.JavaMail.zimbra@efficios.com>
2016-06-04  0:21     ` siddharth teotia

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