linux/arch/ia64
Peter Chubb 05062d96a2 [PATCH] ia64: fix floating-point preemption problem
There've been reports of problems with CONFIG_PREEMPT=y and the high
floating point partition.  This is caused by the possibility of preemption
and rescheduling on a different processor while saving or restioirng the
high partition.

The only places where the FPU state is touched are in ptrace, in
switch_to(), and where handling a floating-point exception.  In switch_to()
preemption is off.  So it's only in trap.c and ptrace.c that we need to
prevent preemption.

Here is a patch that adds commentary to make the conditions clear, and adds
appropriate preempt_{en,dis}able() calls to make it so.  In trap.c I use
preempt_enable_no_resched(), as we're about to return to user space where
the preemption flag will be checked anyway.

Signed-off-by: Peter Chubb <peterc@gelato.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-08 16:21:14 -07:00
..
configs [IA64] Update arch/ia64/configs/tiger_defconfig 2005-05-03 16:27:44 -07:00
dig Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
hp [IA64] use common pxm function 2005-05-03 13:33:18 -07:00
ia32 [IA64] fix compilation warning in sys32_epoll_wait() 2005-06-01 15:44:01 -07:00
kernel [PATCH] ia64: fix floating-point preemption problem 2005-06-08 16:21:14 -07:00
lib [IA64] use fc.i for fluch_icache_range() 2005-05-03 11:27:33 -07:00
mm [IA64] Fill holes in FIXADDR_USER space with zero pages. 2005-06-08 10:58:21 -07:00
oprofile Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
pci Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
scripts Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sn [IA64] fix setting of sn_hub_info->shub_1_1_found 2005-06-03 12:37:53 -07:00
defconfig Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
install.sh Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Kconfig [PATCH] ppc64: remove hidden -fno-omit-frame-pointer for schedule.c 2005-05-05 16:36:32 -07:00
Kconfig.debug Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Makefile Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
module.lds Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00