linux/arch/s390/lib
Heiko Carstens d3d238c774 [S390] nohz: Fix __udelay.
This fixes a regression that came with 934b2857cc
("[S390] nohz/sclp: disable timer on synchronous waits.").
If udelay() gets called from a disabled context it sets the clock comparator
to a value where it expects the next interrupt. When the interrupt happens
the clock comparator gets not reset and therefore the interrupt condition
doesn't get cleared. The result is an endless timer interrupt loop.

In addition this patch fixes also the following:

rcutorture reveals that our __udelay implementation is still buggy,
since it might schedule tasklets, but prevents their execution:

NOHZ: local_softirq_pending 42
NOHZ: local_softirq_pending 02
NOHZ: local_softirq_pending 142
NOHZ: local_softirq_pending 02

To fix this we make sure that only the clock comparator interrupt
is enabled when the enabled wait psw is loaded.
Also no code gets called anymore which might schedule tasklets.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-10-03 21:55:54 +02:00
..
delay.c [S390] nohz: Fix __udelay. 2008-10-03 21:55:54 +02:00
div64.c [S390]: Fix build on 31-bit. 2007-04-25 22:28:53 -07:00
Makefile [S390] remove -traditional 2008-04-30 13:38:44 +02:00
qrnnd.S [S390] Calibrate delay and bogomips. 2007-02-05 21:18:31 +01:00
spinlock.c [S390] do local_irq_restore while spinning in spin_lock_irqsave. 2008-01-26 14:11:31 +01:00
string.c [S390] Fix sparse warnings. 2006-07-12 16:41:55 +02:00
uaccess_mvcos.c [S390] uaccess_mvcos: #ifdef config dependent code. 2008-04-30 13:38:46 +02:00
uaccess_pt.c [S390] uaccess: Always access the correct address space. 2008-04-17 07:47:06 +02:00
uaccess_std.c [S390] Fix futex_atomic_cmpxchg_std inline assembly. 2008-02-19 15:29:35 +01:00
uaccess.h [S390] Get rid of a lot of sparse warnings. 2007-02-05 21:16:47 +01:00