On Mon, Dec 10 2007, jidong xiao wrote:
> Hi,
>
> I am reading the source code of block I/O layer, and now seeing there
> saying "ordering by draining" or "ordering by tag" in
> include/blkdev.h,and the comments in that file says: "Hardbarrier is
> supported with one of the following methods", but what do these two
> methods exactly mean?
ordering by draining means that you empty the pending queue of requests
and then flush the cache to prevent a later issue of a new request to
reach the platter before the older ones. order by tag means that the hw
has a way of being told not to reorder beyond the barrier, in which case
you don't have to drain the queue.
--
Jens Axboe
--
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]
