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

Herbert Xu wrote:

But I have to say that I still don't know of a single place
where one would actually use the volatile variant.

Given that many of the existing users do currently have "volatile", are you comfortable simply removing that behaviour from them? Are you sure that you will not introduce any issues?

Forcing a re-read is only a performance penalty. Removing it can cause behavioural changes.

I would be more comfortable making the default match the majority of the current implementations (ie: volatile semantics). Then, if someone cares about performance they can explicitly validate the call path and convert it over to the non-volatile version.

Correctness before speed...

Chris
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• References:
  • Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures
    • From: Satyam Sharma <[email protected]>
  • Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures
    • From: Paul Mackerras <[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: "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: "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: "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: Satyam Sharma <[email protected]>
  • Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures
    • From: Herbert Xu <[email protected]>

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