On Mon, Sep 11, 2023 at 11:02:00AM +0200, Marc Espie wrote: > I was reading through ps.1, which has two slightly different options > -H Also display information about kernel visible threads. > -k Also display information about kernel threads. > > It's not at all obvious what the difference between these options might be. > kernel threads == kthread(9) created threads
Those should have K in STAT and the name is in () like: 3141 ?? RK/1 4057:57.90 (idle1) kernel visible threads == __tfork_thread(3) created threads for userland applications. For example: 43838 556612 ?? IpU 0:01.58 firefox (firefox/Cache2 I/O) 43838 415551 ?? IpU 0:00.01 firefox (firefox/Cookie) 43838 377915 ?? IpU 0:00.01 firefox (firefox/Worker Launcher) These threads all share the same PID but have different TID. I think the "kernel visible" is there to tell that pure userland threads can not be reported by ps. I think go routines are such an example. > From the log: > -------------------- > revision 1.77 > date: 2011/09/25 00:29:59; author: guenther; state: Exp; lines: +5 -3; > Add -H option to show rthreads, hiding them by default > > Diff from uwe@ > -------------------- > so slightly more info. > > Looking at the code, now this is KERN_PROC_KTHREAD vs KERN_PROC_SHOW_THREADS > in kvm_getprocs(3). > > Now KERN_PROC_KTHREAD is documented, but there is nothing about > KERN_PROC_SHOW_THREADS. > > The code around (dothreads) in kvm* doesn't make things really obvious. > -- :wq Claudio
