On 06/28/2017 10:29 AM, Shaohua Li wrote: > From: Shaohua Li <s...@fb.com> > > Hi, > > Currently blktrace isn't cgroup aware. blktrace prints out task name of > current > context, but the task of current context isn't always in the cgroup where the > BIO comes from. We can't use task name to find out IO cgroup. For example, > Writeback BIOs always comes from flusher thread but the BIOs are for different > blk cgroups. Request could be requeued and dispatched from completely > different > tasks. MD/DM are another examples. This brings challenges if we want to use > blktrace for performance tunning with cgroup enabled. > > This patchset try to fix the gap. We print out cgroup fhandle info in > blktrace. > Userspace can use open_by_handle_at() syscall to find the cgroup by fhandle. > Or > userspace can use name_to_handle_at() syscall to find fhandle for a cgroup and > use a BPF program to filter out blktrace for a specific cgroup. > > The first 6 patches adds export operation handlers for kernfs, so userspace > can > use open_by_handle_at/name_to_handle_at to a kernfs file. Later patches make > blktrace output cgroup info.
Series looks fine to me. I don't know how you want to split or funnel it, since it touches multiple different parts. Would it make sense to split this series into two - one for the kernfs changes, and then a subsequent block series that depend on that? -- Jens Axboe
