On Mon, Sep 08, 2014 at 06:47:35PM -0400, Peter Hurley wrote: > On 09/08/2014 01:59 PM, H. Peter Anvin wrote: > > On 09/08/2014 10:52 AM, One Thousand Gnomes wrote: > >> On Fri, 05 Sep 2014 08:41:52 -0700 > >> "H. Peter Anvin" <hpa@xxxxxxxxx> wrote: > >> > >>> On 09/05/2014 08:31 AM, Peter Hurley wrote: > >>>> > >>>> Which is a bit ironic because I remember when Digital had a team > >>>> working on emulating native x86 apps on Alpha/NT. > >>>> > >>> > >>> Right, because the x86 architecture was obsolete and would never scale... > >> > >> Talking about "not scaling" can anyone explain how a "you need to use > >> set_bit() and friends" bug report scaled into a hundred message plus > >> discussion about ambiguous properties of processors (and nobody has > >> audited all the embedded platforms we support yet, or the weirder ARMs) > >> and a propsal to remove Alpha support. > >> > >> Wouldn't it be *much* simpler to do what I suggested in the first place > >> and use the existing intended for purpose, deliberately put there, > >> functions for atomic bitops, because they are fast on sane processors and > >> they work on everything else. > >> > >> I think the whole "removing Alpha EV5" support is basically bonkers. Just > >> use set_bit in the tty layer. Alpha will continue to work as well as it > >> always has done and you won't design out support for any future processor > >> that turns out not to do byte aligned stores. > >> > >> Alan > >> > > > > Is *that* what we are talking about? I was added to this conversation > > in the middle where it had already generalized, so I had no idea. > > No, this is just what brought this craziness to my attention. > > For example, byte- and short-sized circular buffers could not possibly > be safe either, when the head nears the tail. > > Who has audited global storage and ensured that _every_ byte-sized write > doesn't happen to be adjacent to some other storage that may not happen > to be protected by the same (or any) lock? This was my concern as well. Thanx, Paul -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
