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Re: [Qemu-devel] [PATCH] os: don't corrupt pre-existing memory-backend d
Re: [Qemu-devel] [PATCH] os: don't corrupt pre-existing memory-backend data with prealloc
Fri, 24 Feb 2017 13:18:22 +0100
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On 24/02/2017 13:12, Dr. David Alan Gilbert wrote:
>> Ok, yeah, it makes sense that the compiler can optimize that away without
>> volatile. I wonder if adding volatile has much of a performance impact on
>> this loop...
> I don't think we have anything else in QEMU to do it (other than atomic's
> but we don't need this to be atomic). I don't think the use of memset()
> helps, because the compiler is free to optimise that out as well; so
> I think 'volatile' is a reasonable use (although I seem to have a soft-spot
> for volatile and I know everyone else tells me I'm mad).
Yes, I think it is fine to use volatile here.
Re: [Qemu-devel] [PATCH] os: don't corrupt pre-existing memory-backend data with prealloc, Stefan Hajnoczi, 2017/02/27