Thanks again for the comments. >> Quote the documentation, __kuser_cmpxchg "already includes memory >> barriers as needed," so the code using it shouldn't need anything >> extra. > > Fair enough - but could you put a comment to this effect into the patch? Comment added.
> But I'm still not too happy about even the very unlikely risk of > something executing "random stuff" depending on kernel version. > For now, could you update the comments to that effect that: > > "These kernel functions are available on kernel versions 2.6.15 and > greater" + ", and running this software on earlier versions will result > in undefined behaviour." Comment added. > What I'm suggesting is not to parse information out of the build host, > but rather using the configured toolchain and options and try to > assemble the 64-bit atomic instructions. This would make it easy to > rebuild a generic ARMv6 package to support 64-bit atomics by just adding > -march=armv6zk to CFLAGS. Ah, I get it. I may see if I can come up with a nice test in the near future. For now, revised patch attached.
ompi_armv5-3rd.diff
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