On Wed, Jul 31, 2013 at 2:43 AM, Dave Chinner <david@xxxxxxxxxxxxx> 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 <dave.kleikamp@xxxxxxxxxx> 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! - Sedat - [1] http://marc.info/?t=135947707100013&r=1&w=4 [2] http://marc.info/?l=linux-fsdevel&m=136122569807203&w=4 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
