Messages in this thread | | | Subject | Re: perf events ring buffer memory barrier on powerpc | From | Benjamin Herrenschmidt <> | Date | Mon, 04 Nov 2013 07:57:41 +1100 |
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On Fri, 2013-11-01 at 18:30 +0200, Victor Kaplansky wrote: > "David Laight" <David.Laight@aculab.com> wrote on 11/01/2013 06:25:29 PM: > > gcc will do unexpected memory accesses for bit fields that are > > adjacent to volatile data. > > In particular it may generate 64bit sized (and aligned) RMW cycles > > when accessing bit fields. > > And yes, this has caused real problems. > > Thanks, I am aware about this bug/feature in gcc.
AFAIK, this has been fixed in 4.8 and 4.7.3 ...
Cheers, Ben.
> -- Victor > > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/linuxppc-dev
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