bitops: optimize fns() for more

[PATCH 1/4] lib: make test_bitops compilable into the kernel image

Posted by Yury Norov 1 year, 7 months ago

The test is limited to be compiled as a module. There's no technical
reason for it. Now that the test bears performance benchmark, it would
be reasonable to allow running it at kernel load time, before userspace
starts, to reduce possible jitter.

Signed-off-by: Yury Norov <yury.norov@gmail.com>
---
 lib/Kconfig.debug | 1 -
 1 file changed, 1 deletion(-)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index c63a5fbf1f1c..fc8fe1ea5b49 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2436,7 +2436,6 @@ config TEST_LKM
 
 config TEST_BITOPS
 	tristate "Test module for compilation of bitops operations"
-	depends on m
 	help
 	  This builds the "test_bitops" module that is much like the
 	  TEST_LKM module except that it does a basic exercise of the
-- 
2.40.1

Re: [PATCH 1/4] lib: make test_bitops compilable into the kernel image

Posted by Kuan-Wei Chiu 1 year, 7 months ago

On Thu, May 02, 2024 at 04:32:01PM -0700, Yury Norov wrote:
> The test is limited to be compiled as a module. There's no technical
> reason for it. Now that the test bears performance benchmark, it would
> be reasonable to allow running it at kernel load time, before userspace
> starts, to reduce possible jitter.
> 
> Signed-off-by: Yury Norov <yury.norov@gmail.com>
> ---
>  lib/Kconfig.debug | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index c63a5fbf1f1c..fc8fe1ea5b49 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -2436,7 +2436,6 @@ config TEST_LKM
>  
>  config TEST_BITOPS
>  	tristate "Test module for compilation of bitops operations"
> -	depends on m


Perhaps it would be better to modify the description in the following
help section at the same time?

Reviewed-by: Kuan-Wei Chiu <visitorckw@gmail.com>

>  	help
>  	  This builds the "test_bitops" module that is much like the
>  	  TEST_LKM module except that it does a basic exercise of the
> -- 
> 2.40.1
>

Re: [PATCH 1/4] lib: make test_bitops compilable into the kernel image

Posted by Yury Norov 1 year, 7 months ago

On Fri, May 03, 2024 at 10:00:07AM +0800, Kuan-Wei Chiu wrote:
> On Thu, May 02, 2024 at 04:32:01PM -0700, Yury Norov wrote:
> > The test is limited to be compiled as a module. There's no technical
> > reason for it. Now that the test bears performance benchmark, it would
> > be reasonable to allow running it at kernel load time, before userspace
> > starts, to reduce possible jitter.
> > 
> > Signed-off-by: Yury Norov <yury.norov@gmail.com>
> > ---
> >  lib/Kconfig.debug | 1 -
> >  1 file changed, 1 deletion(-)
> > 
> > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> > index c63a5fbf1f1c..fc8fe1ea5b49 100644
> > --- a/lib/Kconfig.debug
> > +++ b/lib/Kconfig.debug
> > @@ -2436,7 +2436,6 @@ config TEST_LKM
> >  
> >  config TEST_BITOPS
> >  	tristate "Test module for compilation of bitops operations"
> > -	depends on m
> 
> 
> Perhaps it would be better to modify the description in the following
> help section at the same time?

What exactly you want to change?
 
> Reviewed-by: Kuan-Wei Chiu <visitorckw@gmail.com>
> 
> >  	help
> >  	  This builds the "test_bitops" module that is much like the
> >  	  TEST_LKM module except that it does a basic exercise of the
> > -- 
> > 2.40.1
> >

Re: [PATCH 1/4] lib: make test_bitops compilable into the kernel image

Posted by Kuan-Wei Chiu 1 year, 7 months ago

On Thu, May 02, 2024 at 07:14:10PM -0700, Yury Norov wrote:
> On Fri, May 03, 2024 at 10:00:07AM +0800, Kuan-Wei Chiu wrote:
> > On Thu, May 02, 2024 at 04:32:01PM -0700, Yury Norov wrote:
> > > The test is limited to be compiled as a module. There's no technical
> > > reason for it. Now that the test bears performance benchmark, it would
> > > be reasonable to allow running it at kernel load time, before userspace
> > > starts, to reduce possible jitter.
> > > 
> > > Signed-off-by: Yury Norov <yury.norov@gmail.com>
> > > ---
> > >  lib/Kconfig.debug | 1 -
> > >  1 file changed, 1 deletion(-)
> > > 
> > > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> > > index c63a5fbf1f1c..fc8fe1ea5b49 100644
> > > --- a/lib/Kconfig.debug
> > > +++ b/lib/Kconfig.debug
> > > @@ -2436,7 +2436,6 @@ config TEST_LKM
> > >  
> > >  config TEST_BITOPS
> > >  	tristate "Test module for compilation of bitops operations"
> > > -	depends on m
> > 
> > 
> > Perhaps it would be better to modify the description in the following
> > help section at the same time?
> 
> What exactly you want to change?
>
It seems to me that the entire description is written specifically for
the module. For instance, "doesn't run or load unless explicitly
requested by name. for example: modprobe test_bitops." In my view, this
description is no longer accurate.

Regards,
Kuan-Wei

> > Reviewed-by: Kuan-Wei Chiu <visitorckw@gmail.com>
> > 
> > >  	help
> > >  	  This builds the "test_bitops" module that is much like the
> > >  	  TEST_LKM module except that it does a basic exercise of the
> > > -- 
> > > 2.40.1
> > >

Re: [PATCH 1/4] lib: make test_bitops compilable into the kernel image

Posted by Yury Norov 1 year, 7 months ago

On Fri, May 03, 2024 at 10:24:23AM +0800, Kuan-Wei Chiu wrote:
> On Thu, May 02, 2024 at 07:14:10PM -0700, Yury Norov wrote:
> > On Fri, May 03, 2024 at 10:00:07AM +0800, Kuan-Wei Chiu wrote:
> > > On Thu, May 02, 2024 at 04:32:01PM -0700, Yury Norov wrote:
> > > > The test is limited to be compiled as a module. There's no technical
> > > > reason for it. Now that the test bears performance benchmark, it would
> > > > be reasonable to allow running it at kernel load time, before userspace
> > > > starts, to reduce possible jitter.
> > > > 
> > > > Signed-off-by: Yury Norov <yury.norov@gmail.com>
> > > > ---
> > > >  lib/Kconfig.debug | 1 -
> > > >  1 file changed, 1 deletion(-)
> > > > 
> > > > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> > > > index c63a5fbf1f1c..fc8fe1ea5b49 100644
> > > > --- a/lib/Kconfig.debug
> > > > +++ b/lib/Kconfig.debug
> > > > @@ -2436,7 +2436,6 @@ config TEST_LKM
> > > >  
> > > >  config TEST_BITOPS
> > > >  	tristate "Test module for compilation of bitops operations"
> > > > -	depends on m
> > > 
> > > 
> > > Perhaps it would be better to modify the description in the following
> > > help section at the same time?
> > 
> > What exactly you want to change?
> >
> It seems to me that the entire description is written specifically for
> the module. For instance, "doesn't run or load unless explicitly
> requested by name. for example: modprobe test_bitops." In my view, this
> description is no longer accurate.

In-kernel module is still module. Everything is the same as for .ko,
except that it's loaded automatically and earlier for you. To me this
part of the description is correct.

If you feel it should be reworded - feel free to submit a patch. Now
that we add more functionality in that, it's probably worth to do. Not
in this series, though.

Thanks,
Yury

Re: [PATCH 1/4] lib: make test_bitops compilable into the kernel image

Posted by Kuan-Wei Chiu 1 year, 7 months ago

On Fri, May 03, 2024 at 08:13:05AM -0700, Yury Norov wrote:
> On Fri, May 03, 2024 at 10:24:23AM +0800, Kuan-Wei Chiu wrote:
> > On Thu, May 02, 2024 at 07:14:10PM -0700, Yury Norov wrote:
> > > On Fri, May 03, 2024 at 10:00:07AM +0800, Kuan-Wei Chiu wrote:
> > > > On Thu, May 02, 2024 at 04:32:01PM -0700, Yury Norov wrote:
> > > > > The test is limited to be compiled as a module. There's no technical
> > > > > reason for it. Now that the test bears performance benchmark, it would
> > > > > be reasonable to allow running it at kernel load time, before userspace
> > > > > starts, to reduce possible jitter.
> > > > > 
> > > > > Signed-off-by: Yury Norov <yury.norov@gmail.com>
> > > > > ---
> > > > >  lib/Kconfig.debug | 1 -
> > > > >  1 file changed, 1 deletion(-)
> > > > > 
> > > > > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> > > > > index c63a5fbf1f1c..fc8fe1ea5b49 100644
> > > > > --- a/lib/Kconfig.debug
> > > > > +++ b/lib/Kconfig.debug
> > > > > @@ -2436,7 +2436,6 @@ config TEST_LKM
> > > > >  
> > > > >  config TEST_BITOPS
> > > > >  	tristate "Test module for compilation of bitops operations"
> > > > > -	depends on m
> > > > 
> > > > 
> > > > Perhaps it would be better to modify the description in the following
> > > > help section at the same time?
> > > 
> > > What exactly you want to change?
> > >
> > It seems to me that the entire description is written specifically for
> > the module. For instance, "doesn't run or load unless explicitly
> > requested by name. for example: modprobe test_bitops." In my view, this
> > description is no longer accurate.
> 
> In-kernel module is still module. Everything is the same as for .ko,
> except that it's loaded automatically and earlier for you. To me this
> part of the description is correct.
> 
> If you feel it should be reworded - feel free to submit a patch. Now
> that we add more functionality in that, it's probably worth to do. Not
> in this series, though.
> 
> Thanks,
> Yury

Got it, thank you for the explanation! :)

Regards,
Kuan-Wei