[PATCH] D18164: [tsan] Do not instrument reads/writes to instruction profile counters.

[Xinliang David Li via llvm-commits]

On Tue, Mar 15, 2016 at 11:41 AM, Dmitry Vyukov <dvyukov at google.com> wrote:

> dvyukov added a comment.
>
> > It is not about this assumption, but more about racy counter updates not
> being a problem practically
>
>
> Choosing an incorrect code all others equal does not look like the right
> approach to me.
>


I don't agree with you about the 'incorrect code' part.

Having said that, I think it is reasonable to introduce an option to enable
atomic profile counter update.  Tsan can then be safely combined with that.

thanks,

David




>
> > It might -- at least we should measure it. Note that instrumentation run
> is already pretty slow, so we need to be careful not to regress it.
>
>
> Again, is that's the case, that's a very real bug in llvm codegen that
> needs to be fixed. Patching all uses of atomic operations in the world to
> work around that bug is not going to scale (and just wrong).
>
>
> http://reviews.llvm.org/D18164
>
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20160315/2c576b36/attachment.html>