On 12/8/21 2:34 PM, Michael S. Tsirkin wrote: > On Mon, Nov 29, 2021 at 01:46:57PM -0600, Mike Christie wrote: >> The following patches made over Linus's tree, allow the vhost layer to do >> a copy_process on the thread that does the VHOST_SET_OWNER ioctl like how >> io_uring does a copy_process against its userspace app. This allows the >> vhost layer's worker threads to inherit cgroups, namespaces, address >> space, etc and this worker thread will also be accounted for against that >> owner/parent process's RLIMIT_NPROC limit. >> >> If you are not familiar with qemu and vhost here is more detailed >> problem description: >> >> Qemu will create vhost devices in the kernel which perform network, SCSI, >> etc IO and management operations from worker threads created by the >> kthread API. Because the kthread API does a copy_process on the kthreadd >> thread, the vhost layer has to use kthread_use_mm to access the Qemu >> thread's memory and cgroup_attach_task_all to add itself to the Qemu >> thread's cgroups. >> >> The problem with this approach is that we then have to add new functions/ >> args/functionality for every thing we want to inherit. I started doing >> that here: >> >> https://urldefense.com/v3/__https://lkml.org/lkml/2021/6/23/1233__;!!ACWV5N9M2RV99hQ!ceUHd4m4MTJFOGccB9N5r7WonxVoYYT2XPiYwWt2-Vt1Y-DmQirRN8OqKozFLN1h73N6$ >> >> for the RLIMIT_NPROC check, but it seems it might be easier to just >> inherit everything from the beginning, becuase I'd need to do something >> like that patch several times. > > > So who's merging this? Me? Did all patches get acked by appropriate > maintainers? > Not yet. Jens, The last open review comment was from you for the name change and additional patch description info. In this posting, I changed the name from: kernel_worker/kernel_worker_start to user_worker_create/user_worker_start I didn't do the start/create_user_worker format originally discussed because a while back Christoph had given me a review comment about trying to tie everything together into an API. Everything having the user_worker prefix felt nicer in that it was easy to tell the functions and flags went together, and so I thought it would handle his comment too. And patch: [PATCH V6 07/10] io_uring: switch to user_worker should better explain the reason for the switch. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
