Re: why are some atomic_t's not volatile, while most are?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, 07 Aug 2007 16:32:23 -0400
Chris Snook <[email protected]> wrote:

> > It seems like this would fall more into the case of the arch providing 
> > guarantees when using locked/atomic access rather than anything 
> > SMP-related, no?.
> 
> But if you're not using SMP, the only way you get a race condition is if your 
> compiler is reordering instructions that have side effects which are invisible 
> to the compiler.  This can happen with MMIO registers, but it's not an issue 
> with an atomic_t we're declaring in real memory.
> 

Under non-SMP, some compilers would reordering instructions as they think
and C standard informally guarantees all operations on volatile data
are executed in the sequence in which they appear in the source code,
right?

So no reordering happens with volatile, right?

-- Jerry

> 	-- Chris
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux