On Mon 2021-10-25 17:05:03, Steven Rostedt wrote: > On Mon, 25 Oct 2021 11:10:09 -0700 > Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> wrote: > > > It looks like a churn that doesn't really address the problem. > > If we were to allow long names then make it into a pointer and use 16 byte > > as an optimized storage for short names. Any longer name would be a pointer. > > In other words make it similar to dentry->d_iname. > > That would be quite a bigger undertaking too, as it is assumed throughout > the kernel that the task->comm is TASK_COMM_LEN and is nul terminated. And > most locations that save the comm simply use a fixed size string of > TASK_COMM_LEN. Not saying its not feasible, but it would require a lot more > analysis of the impact by changing such a fundamental part of task struct > from a static to something requiring allocation. I fully agree. The evolution of this patchset clearly shows how many code paths depend on the existing behavior. > Unless you are suggesting that we truncate like normal the 16 byte names > (to a max of 15 characters), and add a way to hold the entire name for > those locations that understand it. Yup. If the problem is only with kthreads, it might be possible to store the pointer into "struct kthread" and update proc_task_name(). It would generalize the solution already used by workqueues. I think that something like this was mentioned in the discussion about v1. Best Regards, Petr
