Re: [PATCHES] Reorganization of spinlock defines - Mailing list pgsql-hackers

From Manfred Spraul
Subject Re: [PATCHES] Reorganization of spinlock defines
Date
Msg-id 3F623B0B.20105@colorfullife.com
Whole thread Raw
In response to Re: [PATCHES] Reorganization of spinlock defines  (Manfred Spraul <manfred@colorfullife.com>)
List pgsql-hackers
Manfred Spraul wrote:

> Is the Itanium tas implementation correct? I think it should be 
> xchg4.aqv instead of just xchg4 - as far as I know a normal atomic 
> exchange is is not a memory barrier on Itanium. At least the Linux 
> kernel version contains "cmpxchg4.aqv".

Sorry for the noise, I'm wrong:
Itanium automatically uses acquire semantics with xchg.
See top of page 16 on
http://h21007.www2.hp.com/dspp/files/unprotected/itanium/spinlocks.pdf

--   Manfred



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