On Sun, Sep 11, 2011 at 8:17 PM, Yehuda Sadeh Weinraub <yehudasa@xxxxxxxxx> wrote: > On Sun, Sep 11, 2011 at 8:14 PM, Sage Weil <sage@xxxxxxxxxxxx> wrote: >> On Fri, 9 Sep 2011, Kevin Wolf wrote: >>> Am 08.09.2011 18:36, schrieb Sage Weil: >>> > On Thu, 8 Sep 2011, Kevin Wolf wrote: >>> >> Am 08.09.2011 01:06, schrieb Yehuda Sadeh: >>> >>> The following set of patches improve the qemu-img conversion process >>> >>> performance. When using a higher latency backend, small writes have a >>> >>> severe impact on the time it takes to do image conversion. >>> >>> We switch to using async writes, and we avoid splitting writes due to >>> >>> holes when the holes are small enough. >>> >>> >>> >>> Yehuda Sadeh (2): >>> >>> qemu-img: async write to block device when converting image >>> >>> qemu-img: don't skip writing small holes >>> >>> >>> >>> qemu-img.c | 34 +++++++++++++++++++++++++++------- >>> >>> 1 files changed, 27 insertions(+), 7 deletions(-) >>> >>> >>> >> >>> >> This doesn't seem to be against git master or the block tree. Please rebase. >>> >> >>> >> I think that commit a22f123c may obsolete your patch 2/2. >>> > >>> > With git.kernel.org down, where should I be looking for the latest >>> > upstream? >>> >>> qemu has never been on kernel.org. The interesting repositories for you are: >>> >>> * Upstream: git://git.qemu.org/qemu.git master >>> * Block development branch: git://repo.or.cz/qemu/kevin.git block >> >> Oh right. I've been working from qemu-kvm.git. >> >> I've done some (still minimal) testing, and it looks like the combination >> of a22f123c and the new writeback/flush stuff in librbd gets the same >> result as doing async io explicitly from qemu-img.c. Want to take a look, >> Yehuda? It still defaults to off, so you'll need to add >> rbd_writeback_window=8000000 or similar to the rbd device string. >> > > I'll take a look. I do have a rebased version for the qemu-img async > patch, and I think qemu can benefit from that anyway. > I tested latest librbd with 8k rbd_writeback_window against Kevin's block branch and it seems that the conversion performance surpasses what I had seen with my qemu-img changes. Yehuda -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
