Re: usb kthreads

On Thu, Aug 13, 2009 at 10:09:37AM +0100, Andrew Thompson wrote:
> 2009/8/13 Kostik Belousov <kostikbel_at_gmail.com>
> >
> > On Thu, Aug 13, 2009 at 12:30:02AM -0700, Andrew Thompson wrote:
> > > Hi,
> > >
> > >
> > > Here is an aesthetic patch to change the usb kernel processes to threads,
> > > this hides them from the usual 'ps' output. Please test and review.
> > >
> > >  1290  ??  DL     0:00.00 [usbus0]
> > >  [lots and lots more...]
> > >  1309  ??  DL     0:00.00 [usbus4]
> > >
> > > After the patch they can be seen as kernel threads.
> > >
> > >   PID    TID COMM             TDNAME           CPU  PRI STATE   WCHAN
> > >     0 100000 kernel           swapper            0   68 sleep   sched
> > >     0 100009 kernel           firmware taskq     0   92 sleep   -
> > >     0 100020 kernel           kqueue taskq       0   92 sleep   -
> > >     0 100021 kernel           acpi_task_0        0   92 sleep   -
> > >     0 100022 kernel           acpi_task_1        0   92 sleep   -
> > >     0 100023 kernel           acpi_task_2        0   92 sleep   -
> > >     0 100027 kernel           thread taskq       0   92 sleep   -
> > >     0 100031 kernel           bwi0 taskq         0   16 sleep   -
> > >     0 100032 kernel           bwi0 taskq         0   16 sleep   -
> > >     0 100106 kernel           usbus0             0   20 sleep   wmsg
> > >     0 100107 kernel           usbus0             0   16 sleep   wmsg
> > >     0 100108 kernel           usbus0             0   20 sleep   wmsg
> > >     0 100109 kernel           usbus0             0   20 sleep   wmsg
> > >     [ ... ]
> > >     0 100127 kernel           usbus4             0   20 sleep   wmsg
> > >
> > Can you use this opportunity to change "wmsg" wait channel name
> > to something having "usb" in the name ?
> 
> When the thread is idle this should be `-` ?

Taskqueue loop uses "-" as a name for the wait channel used when no work is
scheduled, see subr_taskqueue.c:404.