Re: [Linux-ia64] ia64_spinlock_contention and NEW_LOCK

[Keith Owens <kaos@sgi.com>]

On Tue, 11 Mar 2003 14:37:23 -0800, 
David Mosberger <davidm@napali.hpl.hp.com> wrote:
>>>>>> On Sat, 08 Mar 2003 00:57:04 +1100, Keith Owens <kaos@sgi.com> said:
>
>  Keith> 2.4.0-test6-ia64-000811 introduced ia64_spinlock_contention
>  Keith> and NEW_LOCK.  AFAICT they have been disabled ever since they
>  Keith> were introduced.  Are there any plans to use this NEW_LOCK
>  Keith> code?
>
>I still think it would make sense to have back-off logic in the
>spinlock contention case, but given that I haven't had time to work on
>it in the last 2 years and nobody else has expressed interest in it, I
>think it's time to just nuke the code.  If someone wants to work on it
>later on, it's been archived often enough that the code can be dug out
>if necessary.

Can you remember what was wrong with the out of line contention code?
The obvious problems are the lack of unwind data, it will not work for
spin locks in modules (PCREL21B will not reach from region 5 to region
7) and the fact that ar.pfs gets corrupted (gcc 2.96 does not recognise
that ar.pfs in the clobber list means leaf functions must now save
ar.pfs).  Were there any other problems?