On Wed, Dec 05, 2018 at 09:46:16AM +0000, Liu, Changpeng wrote: > What's the status of this patch ? anybody pulled it for the branch ? I will merge it for next. > > > -----Original Message----- > > From: Stefan Hajnoczi [mailto:stefanha@xxxxxxxxxx] > > Sent: Friday, November 2, 2018 12:18 PM > > To: Daniel Verkamp <dverkamp@xxxxxxxxxxxx> > > Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx; linux-block@xxxxxxxxxxxxxxx; > > Michael S. Tsirkin <mst@xxxxxxxxxx>; Jason Wang <jasowang@xxxxxxxxxx>; > > Jens Axboe <axboe@xxxxxxxxx>; Paolo Bonzini <pbonzini@xxxxxxxxxx>; > > Christoph Hellwig <hch@xxxxxxxxxxxxx>; Liu, Changpeng > > <changpeng.liu@xxxxxxxxx> > > Subject: Re: [PATCH v9] virtio_blk: add discard and write zeroes support > > > > On Thu, Nov 01, 2018 at 03:40:35PM -0700, Daniel Verkamp wrote: > > > From: Changpeng Liu <changpeng.liu@xxxxxxxxx> > > > > > > In commit 88c85538, "virtio-blk: add discard and write zeroes features > > > to specification" (https://github.com/oasis-tcs/virtio-spec), the virtio > > > block specification has been extended to add VIRTIO_BLK_T_DISCARD and > > > VIRTIO_BLK_T_WRITE_ZEROES commands. This patch enables support for > > > discard and write zeroes in the virtio-blk driver when the device > > > advertises the corresponding features, VIRTIO_BLK_F_DISCARD and > > > VIRTIO_BLK_F_WRITE_ZEROES. > > > > > > Signed-off-by: Changpeng Liu <changpeng.liu@xxxxxxxxx> > > > Signed-off-by: Daniel Verkamp <dverkamp@xxxxxxxxxxxx> > > > --- > > > dverkamp: I've picked up this patch and made a few minor changes (as > > > listed below); most notably, I changed the kmalloc back to GFP_ATOMIC, > > > since it can be called from a context where sleeping is not allowed. > > > To prevent large allocations, I've also clamped the maximum number of > > > discard segments to 256; this results in a 4K allocation and should be > > > plenty of descriptors for most use cases. > > > > > > I also removed most of the description from the commit message, since it > > > was duplicating the comments from virtio_blk.h and quoting parts of the > > > spec without adding any extra information. I have tested this iteration > > > of the patch using crosvm with modifications to enable the new features: > > > https://chromium.googlesource.com/chromiumos/platform/crosvm/ > > > > > > v9 fixes a number of review issues; I didn't attempt to optimize the > > > single-element write zeroes case, so it still does an allocation per > > > request (I did not see any easy place to put the payload that would > > > avoid the allocation). > > > > > > CHANGELOG: > > > v9: [dverkamp] fix LE types in discard struct; cleanups from Ming Lei > > > v8: [dverkamp] replace shifts by 9 with SECTOR_SHIFT constant > > > v7: [dverkamp] use GFP_ATOMIC for allocation that may not sleep; clarify > > > descriptor flags field; comment wording cleanups. > > > v6: don't set T_OUT bit to discard and write zeroes commands. > > > v5: use new block layer API: blk_queue_flag_set. > > > v4: several optimizations based on MST's comments, remove bit field > > > usage for command descriptor. > > > v3: define the virtio-blk protocol to add discard and write zeroes > > > support, first version implementation based on proposed specification. > > > v2: add write zeroes command support. > > > v1: initial proposal implementation for discard command. > > > --- > > > drivers/block/virtio_blk.c | 83 ++++++++++++++++++++++++++++++++- > > > include/uapi/linux/virtio_blk.h | 54 +++++++++++++++++++++ > > > 2 files changed, 135 insertions(+), 2 deletions(-) > > > > Reviewed-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
