Re: [PATCH 0/4] S390: Fine-tuning for six function implementations

From: Ingo Molnar
Date: Tue May 09 2017 - 06:30:41 EST



* Vegard Nossum <vegard.nossum@xxxxxxxxxx> wrote:

> On 05/07/17 19:12, SF Markus Elfring wrote:
> > From: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
> > Date: Sun, 7 May 2017 19:00:09 +0200
> >
> > A few update suggestions were taken into account
> > from static source code analysis.
> >
> > Markus Elfring (4):
> > Combine two function calls into one in show_cacheinfo()
> > Use seq_putc() in show_cpu_summary()
> > Replace six seq_printf() calls by seq_puts()
> > Combine two function calls into one at four places
> >
> > arch/s390/kernel/cache.c | 4 ++--
> > arch/s390/kernel/processor.c | 2 +-
> > arch/s390/kernel/sysinfo.c | 25 +++++++++++--------------
> > 3 files changed, 14 insertions(+), 17 deletions(-)
> >
>
> I'm sorry, I wouldn't normally respond to this, but I was put on the Cc
> after all so I'll give my feedback.
>
> I think these patches are a waste of time and a resources.

Agreed.

> It would be different if your patches fixed actual bugs. This is just mindless
> code transformations that MAY in the best case save a few bytes of code here and
> there (I don't know; you didn't say).

... they might also be acceptable if they came from a genuine newbie who does his
first patch, or if these patches represented genuine interest in the subsystem in
question, by being part of a larger work that adds new features or does some
meaningful code transformations.

They don't: they are Cocceline generated trivial patches from all around the
kernel, and there's probably thousands of such 'problems' in the kernel - do we
really want the churn of thousands of patches?

The cost of individual patches might be small, but their cumulative effect is
non-trivial if we add up all the extra noise and overhad this adds to the kernel
development flow.

> But the potential gains from these incredibly numerous and tiny patches that
> don't fix anything are so small, it's a waste of time, bandwidth, and mental
> capacity for you and for everybody involved.
>
> I just searched my inbox for patches from you and you sent literally _hundreds_
> over the past few days, all doing this crazy printf/puts/putc transformation.
>
> Another bit of searching and I see that I'm not the first one giving you this
> response:
>
> https://lkml.org/lkml/2017/1/23/383 - Jens Axboe
> https://lkml.org/lkml/2017/1/23/262 - Johannes Thumshirn
> https://lkml.org/lkml/2017/1/12/513 - Cyrille Pitchen
> https://lkml.org/lkml/2016/10/24/491 - Theodore Ts'o
> https://lkml.org/lkml/2016/10/7/148 - Dan Carpenter
> https://lkml.org/lkml/2016/9/14/58 - Christian Borntraeger
>
> ...and I'm sure there are many more.

I'm ignoring these minimal effort patches for subsystems I maintain and I suggest
other maintainers do the same.

Thanks,

Ingo