On Wed, Jul 31, 2013 at 10:41 AM, Sedat Dilek wrote: > On Wed, Jul 31, 2013 at 8:40 AM, Sedat Dilek wrote: >> On Wed, Jul 31, 2013 at 2:43 AM, Dave Chinner wrote: >>> On Tue, Jul 30, 2013 at 02:28:20PM -0700, Andrew Morton wrote: >>>> On Thu, 25 Jul 2013 12:50:26 -0500 Dave Kleikamp wrote: >>>> >>>> > This patch series adds a kernel interface to fs/aio.c so that kernel code can >>>> > issue concurrent asynchronous IO to file systems. It adds an aio command and >>>> > file system methods which specify io memory with pages instead of userspace >>>> > addresses. >>>> > >>>> > This series was written to reduce the current overhead loop imposes by >>>> > performing synchronus buffered file system IO from a kernel thread. These >>>> > patches turn loop into a light weight layer that translates bios into iocbs. >>>> >>>> Do you have any performance numbers? >>>> >> >> [ CC Al and Linux-next maintainer ] >> >> The more important question how to test and then provide performance numbers. >> If you give me a test-case I give you numbers! >> >>>> Does anyone care much about loop performance? What's the value here? >>> >>> Yes. Anyone using loopback devices for file-backed devices exposed >>> to containers and VMs cares about the memory and CPU overhead >>> the double caching the existing loop device has. >>> >> >> Yupp, I am here on Ubuntu/precise AMD64 in a so-called WUBI >> environment which makes intensive usage of loopback-device plus FUSE >> driver and $fs-of-your-choice (here: ext4). >> >> Today, I have pulled Dave's aio_loop GIT branch into v3.11-rc3. >> After successful compilation I am running it right now. >> >> I had also tested v6 of the series [1] from February 2013 and >> encouraged Dave to put it into Linux-next [2]. >> Unfortunately, there was no response from Al. >> Again, Dave try to get it into Linux-next! >> > > I have run runltp-lite from latest stable LTP (ltp-full-20130109), but > this reports errors. > I will see later if this happens with a vanilla v3.11-rc3. > These results look similiar, so aio_loop stuff seems to be OK. - Sedat - > See also attached files. > > - Sedat - > >> - Sedat - >> >> [1] http://marc.info/?t=135947707100013&r=1&w=4 >> [2] http://marc.info/?l=linux-fsdevel&m=136122569807203&w=4