Re: [PATCH v9 13/17] x86/split_lock: Disable split lock detection by kernel parameter "nosplit_lock_detect"

Fenghua Yu
2019-06-26T20:47:14Z

On Wed, Jun 26, 2019 at 10:34:52PM +0200, Thomas Gleixner wrote:
> On Tue, 18 Jun 2019, Fenghua Yu wrote:
> >
> > static void split_lock_update_msr(void)
> > {
> > - /* Enable split lock detection */
> > - this_cpu_or(msr_test_ctl_cached, MSR_TEST_CTL_SPLIT_LOCK_DETECT);
> > + if (split_lock_detect_enabled) {
> > + /* Enable split lock detection */
> > + this_cpu_or(msr_test_ctl_cached, MSR_TEST_CTL_SPLIT_LOCK_DETECT);
> > + } else {
> > + /* Disable split lock detection */
>
> Could you please comment the non obvious things and not the obvious ones?
>
> > + this_cpu_and(msr_test_ctl_cached, ~MSR_TEST_CTL_SPLIT_LOCK_DETECT);
>
> It's entirely clear that the if (enabled) path enables it or am I missing
> something?

Ok. I will remove the comments.

Thanks.

-Fenghua