2022-08-26 18:52:15

by Vipin Sharma

Subject: [PATCH v3 1/4] KVM: selftests: Explicitly set variables based on options in dirty_log_perf_test

Variable set via -g are also indirectly set by -e option by omitting
break statement. Set them explicitly so that movement of switch-case
statements does not unintentionally break features.

No functional change intended.

Signed-off-by: Vipin Sharma <[email protected]>
---
tools/testing/selftests/kvm/dirty_log_perf_test.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c
index f99e39a672d3..a03db7f9f4c0 100644
--- a/tools/testing/selftests/kvm/dirty_log_perf_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c
@@ -411,6 +411,8 @@ int main(int argc, char *argv[])
case 'e':
/* 'e' is for evil. */
run_vcpus_while_disabling_dirty_logging = true;
+ dirty_log_manual_caps = 0;
+ break;
case 'g':
dirty_log_manual_caps = 0;
break;
--
2.37.2.672.g94769d06f0-goog

2022-08-26 21:21:59

by Vipin Sharma

Subject: Re: [PATCH v3 1/4] KVM: selftests: Explicitly set variables based on options in dirty_log_perf_test

On Fri, Aug 26, 2022 at 11:45 AM Vipin Sharma <[email protected]> wrote:
>
> Variable set via -g are also indirectly set by -e option by omitting
> break statement. Set them explicitly so that movement of switch-case
> statements does not unintentionally break features.
>
> No functional change intended.
>
> Signed-off-by: Vipin Sharma <[email protected]>
> ---
> tools/testing/selftests/kvm/dirty_log_perf_test.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c
> index f99e39a672d3..a03db7f9f4c0 100644
> --- a/tools/testing/selftests/kvm/dirty_log_perf_test.c
> +++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c
> @@ -411,6 +411,8 @@ int main(int argc, char *argv[])
> case 'e':
> /* 'e' is for evil. */
> run_vcpus_while_disabling_dirty_logging = true;
> + dirty_log_manual_caps = 0;
> + break;

@Sean, I hope you intentionally didn't write a break between -e and -g
when you created the patch and it is not just a missed thing :)


> case 'g':
> dirty_log_manual_caps = 0;
> break;
> --
> 2.37.2.672.g94769d06f0-goog
>

2022-09-21 18:07:17

by David Matlack

Subject: Re: [PATCH v3 1/4] KVM: selftests: Explicitly set variables based on options in dirty_log_perf_test

On Fri, Aug 26, 2022 at 02:12:49PM -0700, Vipin Sharma wrote:
> On Fri, Aug 26, 2022 at 11:45 AM Vipin Sharma <[email protected]> wrote:
> >
> > Variable set via -g are also indirectly set by -e option by omitting
> > break statement. Set them explicitly so that movement of switch-case
> > statements does not unintentionally break features.
> >
> > No functional change intended.
> >
> > Signed-off-by: Vipin Sharma <[email protected]>
> > ---
> > tools/testing/selftests/kvm/dirty_log_perf_test.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c
> > index f99e39a672d3..a03db7f9f4c0 100644
> > --- a/tools/testing/selftests/kvm/dirty_log_perf_test.c
> > +++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c
> > @@ -411,6 +411,8 @@ int main(int argc, char *argv[])
> > case 'e':
> > /* 'e' is for evil. */
> > run_vcpus_while_disabling_dirty_logging = true;
> > + dirty_log_manual_caps = 0;
> > + break;
>
> @Sean, I hope you intentionally didn't write a break between -e and -g
> when you created the patch and it is not just a missed thing :)

I'm pretty sure the missing break here is by accident. If it was on
purpose I would expect Sean (especially) to have called it out the
subtle change in the commit message and probably add a comment here.
Also I can't think of any reason why
run_vcpus_while_disabling_dirty_logging=true would require
dirty_log_manual_caps=0.

Can you change this patch to just add a break and add a fixes tag to the
commit message?

Fixes: cfe12e64b065 ("KVM: selftests: Add an option to run vCPUs while disabling dirty logging")


>
>
> > case 'g':
> > dirty_log_manual_caps = 0;
> > break;
> > --
> > 2.37.2.672.g94769d06f0-goog
> >