On Wednesday, August 24, 2005 2:45 pm, Alan Cox wrote: > And in more detail from the deviceiobook.. > > <para> > In addition to write posting, on some large multiprocessing > systems > (e.g. SGI Challenge, Origin and Altix machines) posted writes > won't > be strongly ordered coming from different CPUs. Thus it's > important > to properly protect parts of your driver that do memory-mapped > writes > with locks and use the <function>mmiowb</function> to make > sure they > arrive in the order intended. Issuing a regular > <function>readX </function> will also ensure write ordering, but > should only be used > when the driver has to be sure that the write has actually > arrived > at the device (not that it's simply ordered with respect to > other > writes), since a full <function>readX</function> is a > relatively expensive operation. > </para>
Yeah, wrote that too :). io_ordering.txt should probably just get folded into deviceiobook at some point... Or we could just replace both with URL pointers to LDD vol. 3. ;) Jesse - 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/
