svn commit: r184558 - head/sys/dev/acpica/Osd

[John Baldwin]

On Monday 03 November 2008 11:27:13 am Jung-uk Kim wrote:
> On Monday 03 November 2008 11:08 am, Alexander Motin wrote:
> > Jung-uk Kim wrote:
> > > On Sunday 02 November 2008 07:50 am, Alexander Motin wrote:
> > >> Author: mav
> > >> Date: Sun Nov  2 12:50:16 2008
> > >> New Revision: 184558
> > >> URL: http://svn.freebsd.org/changeset/base/184558
> > >>
> > >> Log:
> > >>   As soon as we have several threads per process now, it is not
> > >> correct to use process ID as ACPI thread ID. Concurrent requests
> > >> with equal thread IDs broke ACPI mutexes operation causing
> > >> unpredictable errors including AE_AML_MUTEX_NOT_ACQUIRED that I
> > >> have seen.
> > >>
> > >>   Use kernel thread ID instead of process ID for ACPI thread.
> > >
> > > Sorry but this patch is incorrect, i.e., td_tid is not unique. 
> > > You have to use curthread or (p_pid, td_tid) pair. 
> > > Unfortunately, even if you correct this problem, you also have to
> > > correct ACPI_THREAD_ID definition, which is in the vendor code. 
> > > That's why it wasn't done yet and it is more complicated than you
> > > think, i.e., ACPI-CA assumes sizeof(ACPI_THREAD_ID) ==
> > > sizeof(int), etc.  Please see the related ACPI-CA bugs:
> >
> > I'm also sorry, but that is what I see:
> > typedef __int32_t       __lwpid_t;      /* Thread ID (a.k.a. LWP)
> > */ ...
> > td->td_tid = alloc_unr(tid_unrhdr);
> > ...
> > tid_unrhdr = new_unrhdr(PID_MAX + 2, INT_MAX, &tid_lock);
> >
> > So what have I missed, where is the problem? Why td_tid is not
> > unique and where is the size problem?
> 
> td_tid is unique for a process, i.e., it is used to identify thread 
> with a same pid, if I am not totally mistaken.  If you want a true 
> unique tid, you have to use struct thread *.

No, td_tid is globally unique.

-- 
John Baldwin