[PATCH 0/11] Update version of write stream ID patchset

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

 



It's been a while since I last posted the write stream ID patchset, but
here is an updated version.

The original patchset was centered around the current NVMe streams
proposal, but there was a number of issues with that. It's now in a
much beter state, and hopefully will make it into 1.3 of the spec
soon.

To quickly re-summarize the intent behind write stream IDs, it's to
be able to provide a hint to the underlying storage device on what
writes could feasibly be grouped together. If the device is able to
group writes of similar life times on media, then we can greatly reduce
the amount of data that needs to be copied around at garbage collection
time. This gives us a better write amplification factor, which leads
to better device life times and better (and more predictable)
performance at steady staet.

There's been a number of changes to this patchset since it was last
posted. In summary:

1) The bio parts have been bumped to carry 16 bits of stream data, up
   from 8 and 12 in the original series.

2) Since the interface grew some more options, I've moved away from
   fadvise and instead added a new system call. I don't feel strongly
   about what interface we use here, another option would be to have a
   (big) set of fcntl() commands instead.

3) The kernel now manages the ID space, since we have moved to a host
   assigned model. This is done on a backing_dev_info basis, and the
   btrfs patch has been updated to show how this can be used for nested
   devices on btrfs/md/dm/etc. This could be moved to the request queue
   as well, again I don't feel too strongly aboout this specific part.

Those are the big changes.

The patches are against Linus' current -git tip.

-- 
Jens Axboe


--
To unsubscribe from this list: send the line "unsubscribe linux-block" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux RAID]     [Linux SCSI]     [Linux ATA RAID]     [IDE]     [Linux Wireless]     [Linux Kernel]     [ATH6KL]     [Linux Bluetooth]     [Linux Netdev]     [Kernel Newbies]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Device Mapper]

  Powered by Linux