linux/arch/x86
Konrad Rzeszutek Wilk a945928ea2 xen: Do not enable spinlocks before jump_label_init() has executed
xen_init_spinlocks() currently calls static_key_slow_inc() before
jump_label_init() is invoked. When CONFIG_JUMP_LABEL is set (which usually is
the case) the effect of this static_key_slow_inc() is deferred until after
jump_label_init(). This is different from when CONFIG_JUMP_LABEL is not set, in
which case the key is set immediately. Thus, depending on the value of config
option, we may observe different behavior.

In addition, when we come to __jump_label_transform() from jump_label_init(),
the key (paravirt_ticketlocks_enabled) is already enabled. On processors where
ideal_nop is not the same as default_nop this will cause a BUG() since it is
expected that before a key is enabled the latter is replaced by the former
during initialization.

To address this problem we need to move
static_key_slow_inc(&paravirt_ticketlocks_enabled) so that it is called
after jump_label_init(). We also need to make sure that this is done before
other cpus start to boot. early_initcall appears to be  a good place to do so.
(Note that we cannot move whole xen_init_spinlocks() there since pv_lock_ops
need to be set before alternative_instructions() runs.)

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v2: Added extra comments in the code]
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
2013-09-24 16:22:26 -04:00
..
boot x86, efi: correct call to free_pages 2013-07-26 15:22:32 +01:00
configs
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2013-07-24 11:05:18 -07:00
ia32 mm: remove free_area_cache 2013-07-10 18:11:34 -07:00
include Linux 3.11-rc7 2013-09-09 12:05:37 -04:00
kernel Linux 3.11-rc7 2013-09-09 12:05:37 -04:00
kvm KVM: MMU: avoid fast page fault fixing mmio page fault 2013-07-18 12:26:57 +02:00
lguest Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-07-06 14:09:38 -07:00
lib
math-emu
mm x86 get_unmapped_area: Access mmap_legacy_base through mm_struct member 2013-08-22 10:19:35 -07:00
net
oprofile
pci x86: delete __cpuinit usage from all x86 files 2013-07-14 19:36:56 -04:00
platform arch/x86/platform/ce4100/ce4100.c: include reboot.h 2013-07-31 14:41:02 -07:00
power
realmode
syscalls
tools x86, relocs: Move __vvar_page from S_ABS to S_REL 2013-06-12 15:14:57 -07:00
um um: remove dead code 2013-07-19 11:35:32 +02:00
vdso x86/vdso: Convert use of typedef ctl_table to struct ctl_table 2013-06-19 15:06:09 +02:00
video
xen xen: Do not enable spinlocks before jump_label_init() has executed 2013-09-24 16:22:26 -04:00
.gitignore
Kbuild
Kconfig kvm guest: Add configuration support to enable debug information for KVM Guests 2013-08-09 07:54:18 -07:00
Kconfig.cpu
Kconfig.debug Merge branch 'kconfig-diet' from Dave Hansen 2013-07-04 11:25:51 -07:00
Makefile x86/platform: Add kvmconfig to the phony targets 2013-06-23 12:17:35 +02:00
Makefile.um
Makefile_32.cpu