mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 01:10:04 +00:00
x86/cpu: Fix typos and improve the comments in sync_core()
- Fix typos. - Move the compiler barrier comment to the top, because it's valid for the whole function, not just the legacy branch. Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200818053130.GA3161093@gmail.com Reviewed-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
This commit is contained in:
parent
8610981399
commit
40eb0cb493
1 changed files with 8 additions and 8 deletions
|
@ -47,16 +47,19 @@ static inline void iret_to_self(void)
|
|||
*
|
||||
* b) Text was modified on a different CPU, may subsequently be
|
||||
* executed on this CPU, and you want to make sure the new version
|
||||
* gets executed. This generally means you're calling this in a IPI.
|
||||
* gets executed. This generally means you're calling this in an IPI.
|
||||
*
|
||||
* If you're calling this for a different reason, you're probably doing
|
||||
* it wrong.
|
||||
*
|
||||
* Like all of Linux's memory ordering operations, this is a
|
||||
* compiler barrier as well.
|
||||
*/
|
||||
static inline void sync_core(void)
|
||||
{
|
||||
/*
|
||||
* The SERIALIZE instruction is the most straightforward way to
|
||||
* do this but it not universally available.
|
||||
* do this, but it is not universally available.
|
||||
*/
|
||||
if (static_cpu_has(X86_FEATURE_SERIALIZE)) {
|
||||
serialize();
|
||||
|
@ -67,10 +70,10 @@ static inline void sync_core(void)
|
|||
* For all other processors, there are quite a few ways to do this.
|
||||
* IRET-to-self is nice because it works on every CPU, at any CPL
|
||||
* (so it's compatible with paravirtualization), and it never exits
|
||||
* to a hypervisor. The only down sides are that it's a bit slow
|
||||
* to a hypervisor. The only downsides are that it's a bit slow
|
||||
* (it seems to be a bit more than 2x slower than the fastest
|
||||
* options) and that it unmasks NMIs. The "push %cs" is needed
|
||||
* because, in paravirtual environments, __KERNEL_CS may not be a
|
||||
* options) and that it unmasks NMIs. The "push %cs" is needed,
|
||||
* because in paravirtual environments __KERNEL_CS may not be a
|
||||
* valid CS value when we do IRET directly.
|
||||
*
|
||||
* In case NMI unmasking or performance ever becomes a problem,
|
||||
|
@ -81,9 +84,6 @@ static inline void sync_core(void)
|
|||
* CPUID is the conventional way, but it's nasty: it doesn't
|
||||
* exist on some 486-like CPUs, and it usually exits to a
|
||||
* hypervisor.
|
||||
*
|
||||
* Like all of Linux's memory ordering operations, this is a
|
||||
* compiler barrier as well.
|
||||
*/
|
||||
iret_to_self();
|
||||
}
|
||||
|
|
Loading…
Reference in a new issue