Re: [patch] spinlocks: remove 'volatile'

On Thu, 6 Jul 2006, Chris Friesen wrote:
> 
> As long as you're not talking to external devices, each cpu must be coherent
> with respect to itself, no?  It's allowed to execute out-of-order, but it
> needs to make sure that by doing so it doesn't cause changes that are visible
> to software.

Right. But then "volatile" won't really matter either, unless you have 
some _ordering_ constraint, in which case "volatile" is not enough unless 
you're guaranteed to be single-threaded.

In other words, again, "volatile" is almost always the wrong thing to 
have, and just makes you _think_ your code is correct.

		Linus
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---

• References:
  • Re: [patch] uninline init_waitqueue_*() functions
    • From: Ingo Molnar <[email protected]>
  • Re: [patch] uninline init_waitqueue_*() functions
    • From: Andrew Morton <[email protected]>
  • Re: [patch] uninline init_waitqueue_*() functions
    • From: Ingo Molnar <[email protected]>
  • Re: [patch] uninline init_waitqueue_*() functions
    • From: Andrew Morton <[email protected]>
  • Re: [patch] uninline init_waitqueue_*() functions
    • From: Linus Torvalds <[email protected]>
  • Re: [patch] uninline init_waitqueue_*() functions
    • From: Ingo Molnar <[email protected]>
  • Re: [patch] uninline init_waitqueue_*() functions
    • From: Linus Torvalds <[email protected]>
  • Re: [patch] uninline init_waitqueue_*() functions
    • From: Ingo Molnar <[email protected]>
  • Re: [patch] uninline init_waitqueue_*() functions
    • From: Linus Torvalds <[email protected]>
  • Re: [patch] uninline init_waitqueue_*() functions
    • From: Linus Torvalds <[email protected]>
  • [patch] spinlocks: remove 'volatile'
    • From: Ingo Molnar <[email protected]>
  • Re: [patch] spinlocks: remove 'volatile'
    • From: "linux-os \(Dick Johnson\)" <[email protected]>
  • Re: [patch] spinlocks: remove 'volatile'
    • From: Arjan van de Ven <[email protected]>
  • Re: [patch] spinlocks: remove 'volatile'
    • From: Mark Lord <[email protected]>
  • Re: [patch] spinlocks: remove 'volatile'
    • From: Linus Torvalds <[email protected]>
  • Re: [patch] spinlocks: remove 'volatile'
    • From: "Chris Friesen" <[email protected]>
  • Re: [patch] spinlocks: remove 'volatile'
    • From: Mark Lord <[email protected]>
  • Re: [patch] spinlocks: remove 'volatile'
    • From: "Chris Friesen" <[email protected]>

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