Subj : Re: Memory visibility and MS Interlocked instructions
To   : comp.programming.threads
From : David Schwartz
Date : Thu Aug 25 2005 11:37 am


"David Schwartz" <davids@webmaster.com> wrote in message 
news:dekvgl$vj1$1@nntp.webmaster.com...

>> But this would require that MS insert membars on all volatile accesses,
>> because there is, in general, no way to know whether another part of the
>> program uses an interlocked instruction.  Do MS and MS-compatible 
>> compilers
>> really do that?

>    On x86, it's not needed. I'm not sure about other platforms.

    Here's the famous quote from the Linux kernel:

 * For now, "wmb()" doesn't actually do anything, as all
 * Intel CPU's follow what Intel calls a *Processor Order*,
 * in which all writes are seen in the program order even
 * outside the CPU.

    DS

.