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Re: [PATCH v2] PowerPC: Fix a race condition when eliding a lock
- From: "Carlos O'Donell" <carlos at redhat dot com>
- To: Adhemerval Zanella <adhemerval dot zanella at linaro dot org>, Torvald Riegel <triegel at redhat dot com>
- Cc: Tulio Magno Quites Machado Filho <tuliom at linux dot vnet dot ibm dot com>, libc-alpha at sourceware dot org, munroesj at linux dot vnet dot ibm dot com
- Date: Tue, 25 Aug 2015 13:09:12 -0400
- Subject: Re: [PATCH v2] PowerPC: Fix a race condition when eliding a lock
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On 08/25/2015 12:47 PM, Adhemerval Zanella wrote:
> I do not know which is better, since it will tie the ELIDE_LOCK implementation
> with current internal pthread definitions.
I prefer the idea of passing an inline function to ELIDE_LOCK
and have the inline funciton do what it needs to compute is_lock_free
and then return the result. This leaves ELIDE_LOCK simpler.
However, I'm not really for one way or the other, they are roughly
all the same. The inline function is just a cleaner interface and puts
the evaluation of is_lock_free all in one place to be inlined by the
I think the end result of Torvald's comments is that when we switch to
C11 atomics, we'll need to reference __lock with atomic_load rleaxed, so
we might as well start today.