Messages in this thread | | | Date | Thu, 19 May 2016 11:00:13 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH v2] locking/rwsem: Add reader-owned state to the owner field |
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On Wed, May 18, 2016 at 10:26:06AM -0700, Paul E. McKenney wrote: > On Wed, May 18, 2016 at 01:05:55PM +0200, Peter Zijlstra wrote:
> > Alternatively, could we try and talk to our GCC friends to make sure GCC > > doesn't tear loads/stores irrespective of what the C language spec > > allows? > > Interestingly enough, they used to make that guarantee, but removed it > when C11 showed up.
Did someone tell them this was a regression and have them fix it? They can't just change things like this.
> Me, I would feel better explicitly telling the compiler what I needed. > It is all too easy for bugs to slip in otherwise, especially when the > gcc guys are adding exciting new optimizations.
GCC guys (as opposed to the language guys) should be far more amenable to our needs, and I don't think they want to break the kernel any more than we do.
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