Alpha load locked granularity

Article: Haswell Transactional Memory Alternatives
By: anon (, September 2, 2012 5:23 pm
Room: Moderated Discussions
Paul A. Clayton ( on September 1, 2012 7:29 am wrote:
> rwessel ( on August 31, 2012 8:54 pm
> wrote:
> > Paul A. Clayton ( on
> >
> August 28, 2012 10:28 am wrote:
> [snip]
> >> (The Alpha architectural
> suggestion for portability of not
> >> placing two atomic operands within
> the same 8 KiB page seems
> >> a bit excessive.)
> [snip]
> > While it
> might have been changed subsequently, the original
> > Alpha architectural
> suggestion was that such items be quadword
> > aligned and in their own
> "large cache block", which were defined as "likely
> > be(ing) 32, 64, 128 or
> 256 bytes".
> I seem to have misinterpreted a statement in version 4 (1998) of
> the Alpha Architecture Handbook--"A processor’s locked range is the aligned
> block of 2**N bytes that includes the locked_physical_address. The 2**N value is
> implementation dependent. It is at least 16 (minimum lock range is an aligned
> 16-byte block) and is at most the page size for that implementation (maximum
> lock range is one physical
> page)."--and did not remember another statement just
> a page later--"Hardware implementations are encouraged to lock no more than 128
> bytes. Software implementations are encouraged to separate locked locations by
> at least 128 bytes from
> other locations that could potentially be written by
> another processor while the first location is locked."
> It seems Alpha did
> settle on a single "recommended" number, though I think allowing for page-sized
> granularity might be excessive. (An implementation could--at some complexity
> cost--still use primarily page-sized coherence while supporting a finer
> granularity for LLDx_L/STx_C, though 8KiB seems excessively large for the common
> coherence granularity.)
> (Of course, Alpha did eventually support 64 KiB base
> pages.)

Didn't Alpha always support 64 KB, in addition to 8 KB, 512 KB, and 2 MB page sizes?
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TopicPosted ByDate
Article: Haswell TM AlternativesDavid Kanter2012/08/21 09:17 PM
  Article: Haswell TM AlternativesHåkan Winbom2012/08/21 11:52 PM
    Article: Haswell TM AlternativesDavid Kanter2012/08/22 01:06 AM
  Article: Haswell TM Alternativesanon2012/08/22 08:46 AM
    Article: Haswell TM AlternativesLinus Torvalds2012/08/22 09:16 AM
      Article: Haswell TM AlternativesDoug S2012/08/24 08:34 AM
    AMD's ASF even more limitedPaul A. Clayton2012/08/22 09:20 AM
      AMD's ASF even more limitedLinus Torvalds2012/08/22 09:41 AM
        Compiler use of ll/sc?Paul A. Clayton2012/08/28 09:28 AM
          Compiler use of ll/sc?Linus Torvalds2012/09/08 12:58 PM
            Lock recognition?Paul A. Clayton2012/09/10 01:17 PM
              Sorry, I was confusedPaul A. Clayton2012/09/13 10:56 AM
  Filter to detect store conflictsPaul A. Clayton2012/08/22 09:19 AM
  Article: Haswell TM Alternativesbakaneko2012/08/22 02:02 PM
    Article: Haswell TM AlternativesDavid Kanter2012/08/22 02:45 PM
      Article: Haswell TM Alternativesbakaneko2012/08/22 09:56 PM
  Cache line granularity?Paul A. Clayton2012/08/28 09:28 AM
    Cache line granularity?David Kanter2012/08/31 08:13 AM
      A looser definition might have advantagesPaul A. Clayton2012/09/01 06:29 AM
    Cache line granularity?rwessel2012/08/31 07:54 PM
      Alpha load locked granularityPaul A. Clayton2012/09/01 06:29 AM
        Alpha load locked granularityanon2012/09/02 05:23 PM
          Alpha pages groupsPaul A. Clayton2012/09/03 04:16 AM
  An alternative implementationMaynard Handley2012/11/20 09:52 PM
    An alternative implementationbakaneko2012/11/21 05:52 AM
      Guarding unread values?Paul A. Clayton2012/11/21 08:39 AM
        Guarding unread values?bakaneko2012/11/21 11:25 AM
    TM granularity and versioningPaul A. Clayton2012/11/21 08:27 AM
      TM granularity and versioningMaynard Handley2012/11/21 10:52 AM
        Indeed, TM (and coherence) has devilish details (NT)Paul A. Clayton2012/11/21 10:56 AM
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