Re: [Qemu-devel] [PATCH RFC for-3.0-rc3 0/3] qemu-img: Disable copy offloading by default

2018-07-27 Thread Kevin Wolf
Am 27.07.2018 um 14:14 hat Fam Zheng geschrieben: > On Fri, Jul 27, 2018 at 6:29 PM Kevin Wolf wrote: > > > > Am 27.07.2018 um 05:33 hat Fam Zheng geschrieben: > > > Kevin pointed out that both glibc and kernel provides a slow fallback of > > > copy_file_range which hurts thin provisioning. This

Re: [Qemu-devel] [PATCH RFC for-3.0-rc3 0/3] qemu-img: Disable copy offloading by default

2018-07-27 Thread Fam Zheng
On Fri, Jul 27, 2018 at 6:29 PM Kevin Wolf wrote: > > Am 27.07.2018 um 05:33 hat Fam Zheng geschrieben: > > Kevin pointed out that both glibc and kernel provides a slow fallback of > > copy_file_range which hurts thin provisioning. This is particularly true for > > thin LVs, because host_device

Re: [Qemu-devel] [PATCH RFC for-3.0-rc3 0/3] qemu-img: Disable copy offloading by default

2018-07-27 Thread Kevin Wolf
Am 27.07.2018 um 05:33 hat Fam Zheng geschrieben: > Kevin pointed out that both glibc and kernel provides a slow fallback of > copy_file_range which hurts thin provisioning. This is particularly true for > thin LVs, because host_device driver cannot get allocation info from the > volume, and

[Qemu-devel] [PATCH RFC for-3.0-rc3 0/3] qemu-img: Disable copy offloading by default

2018-07-26 Thread Fam Zheng
Kevin pointed out that both glibc and kernel provides a slow fallback of copy_file_range which hurts thin provisioning. This is particularly true for thin LVs, because host_device driver cannot get allocation info from the volume, and copy_file_range is called on every sectors, making the dst