Christoph Lameter <[email protected]> wrote:
> You need to explain the difference between the compiler reordering and the
> control of the compilers arrangement of loads and stores and the cpu
> reordering of stores and loads.
Hmmm... I would hope people looking at this doc would understand that, but
I'll see what I can come up with.
> Note that IA64 has a much more complete set of means to reorder stores and
> loads. i386 and x84_64 processors can only do limited reordering. So it may
> make sense to deal with general reordering and then explain i386 as a
> specific limited case.
Don't you need to use sacrifice_goat() for controlling the IA64? :-)
Besides, I'm not sure that I need to explain that any CPU is a limited case;
I'm primarily trying to define the basic minimal guarantees you can expect
from using a memory barrier, and what might happen if you don't. It shouldn't
matter which arch you're dealing with, especially if you're writing a driver.
I tried to create arch-specific sections for describing arch-specific implicit
barriers and the extent of the explicit memory barriers on each arch, but the
i386 section was generating lots of exceptions that it looked infeasible to
describe them; besides, you aren't allowed to rely on such features outside of
arch code (I count arch-specific drivers as "arch code" for this).
> See the "Intel Itanium Architecture Software Developer's Manual"
> (available from intels website). Look at Volume 1 section 2.6
> "Speculation" and 4.4 "Memory Access"
I've added that to the refs, thanks.
> Also the specific barrier functions of various locking elements varies to
> some extend.
Please elaborate.
David
-
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]
