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From: Robert Love <rml@tech9.net>
To: prash_t@softhome.net
Cc: linux-kernel@vger.kernel.org
Subject: Re: Inconsistency in changing the state of task ??
Date: 06 Mar 2003 15:05:39 -0500	[thread overview]
Message-ID: <1046981138.684.7.camel@phantasy.awol.org> (raw)
In-Reply-To: <courier.3E674902.000007D9@softhome.net>

On Thu, 2003-03-06 at 08:11, prash_t@softhome.net wrote:

> Thanks Robert for the reply.
> But I notice that __set_current_state() is same as current->state. So, I 
> didn't understand the safety factor on using __set_current_state( ). 

There is no safety with __set_current_state().  It is just an
abstraction.

The safety comes from set_current_state(), which ensures memory
ordering.

This is an issue not just on SMP, but on a weakly ordered processor like
Alpha.

> Also why should I use __set_current_state() instead of set_current_state() 
> when the later is SMP safe.

You only use __set_current_state() if you know you do not need to ensure
memory ordering constraints.

	Robert Love


  parent reply	other threads:[~2003-03-06 19:54 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-03-04  8:36 Inconsistency in changing the state of task ?? prash_t
2003-03-04 17:51 ` Robert Love
2003-03-06 13:11   ` prash_t
2003-03-06 13:31     ` Richard B. Johnson
2003-03-06 20:05     ` Robert Love [this message]
  -- strict thread matches above, loose matches on Subject: below --
2003-03-07  4:22 Perez-Gonzalez, Inaky

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