Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures

On Tue, Aug 21, 2007 at 07:33:49PM +1000, Paul Mackerras wrote:
> So the whole discussion is irrelevant to ARM, PowerPC and any other
> architecture except x86[-64].

It's even irrelevant on x86 because all modifying operations on atomic_t 
are coded in inline assembler and will always be RMW no matter
if atomic_t is volatile or not.

[ignoring atomic_set(x, atomic_read(x) + 1) which nobody should do]

The only issue is if atomic_t should have a implicit barrier or not.
My personal opinion is yes -- better safe than sorry. And any code
impact it may have is typically dwarved by the next cache miss anyways,
so it doesn't matter much.

-Andi

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---

• References:
  • Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures
    • From: "Paul E. McKenney" <[email protected]>
  • Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures
    • From: Herbert Xu <[email protected]>
  • Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures
    • From: "Paul E. McKenney" <[email protected]>
  • Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures
    • From: Christoph Lameter <[email protected]>
  • Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures
    • From: Chris Snook <[email protected]>
  • Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures
    • From: Segher Boessenkool <[email protected]>
  • Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures
    • From: Russell King <[email protected]>
  • Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures
    • From: Segher Boessenkool <[email protected]>
  • Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures
    • From: Russell King <[email protected]>
  • Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures
    • From: Paul Mackerras <[email protected]>

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