linux-kernel - Re: [RFC PATCH 2/2] clocksource: Use cpumask_first_but() in clocksource_verify_choose

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Message-ID: <aEu-b9IkdDrFRFTS@vaxr-BM6660-BM6360>
Date: Fri, 13 Jun 2025 14:00:15 +0800
From: I Hsin Cheng <richard120310@...il.com>
To: Yury Norov <yury.norov@...il.com>
Cc: linux@...musvillemoes.dk, jstultz@...gle.com, tglx@...utronix.de,
	sboyd@...nel.org, linux-kernel@...r.kernel.org,
	eleanor15x@...il.com, visitorckw@...il.com, jserv@...s.ncku.edu.tw,
	skhan@...uxfoundation.org, linux-kernel-mentees@...ts.linux.dev
Subject: Re: [RFC PATCH 2/2] clocksource: Use cpumask_first_but() in
 clocksource_verify_choose_cpus()

On Fri, Jun 13, 2025 at 01:02:38AM -0400, Yury Norov wrote:
> I Hsin,
> 
> This exact change has already been submitted by me and is under review.
> 
> https://lore.kernel.org/all/20250604232550.40491-2-yury.norov@gmail.com/
> 
> I don't understand why are you undercutting my work, and moreover do it 
> for the second time.
> 
> For the first time you submitted something that duplicates my another
> patch from the exact same series. John Stultz has pointed that, so you're
> surely aware.
> 
> https://lore.kernel.org/all/CANDhNCoJ_MmpEfyuL+JWav+NUfQDH3dm196JSE-Mv3QrPUzi3g@mail.gmail.com/
> 
> Kernel development process implies that one makes sure that his work
> is unique and doesn't break someone else's development, at one's best
> knowledge.
> 
> What you're doing not only breaks this rule. You're in fact trying to
> get credit for the work that is done by someone else. This is the
> definition of fraud.
> 
> I cannot make sure that any other patches from you are unique and
> written by actually you. Therefore, I will not take your work anymore.
> 
> I encourage everyone else to be careful working with I Hsing Cheng
> and check his patches for uniqueness, at minimum.  
>

However, I have to defend myself while I'm sincerely sorry for causing
your trouble. I think the statement here is an excessive accusation, if
I mean to stole other's patch, why would I send the patch to the author?

I hope you can understand this, I was not careful enough and made this
trouble, I should've browse through your patch series thoroughly and
thus made this trouble, I'm sorry, but the accusation here is too over
for me.

Thanks,
I Hsin Cheng


> NAKed-by: Yury Norov <yury.norov@...il.com>
> 
> Thanks,
> Yury
> 
> On Fri, Jun 13, 2025 at 11:34:47AM +0800, I Hsin Cheng wrote:
> > Utilize cpumask_first_but() helper instead of first using
> > cpumask_first() and then cpumask_next(). The logic is the same here,
> > using the new helper will make it more conscious.
> > 
> > Use bloat-o-meter to check the impact on code size, the result is the
> > same, does not have positive impact nor negative impact.
> > 
> > $ ./scripts/bloat-o-meter vmlinux_old vmlinux_new
> > add/remove: 0/0 grow/shrink: 0/0 up/down: 0/0 (0)
> > Function                                     old     new   delta
> > Total: Before=22590709, After=22590709, chg +0.00%
> > 
> > Signed-off-by: I Hsin Cheng <richard120310@...il.com>
> > ---
> > Generally speaking, I think this is just a small tweak on the code,
> > making it more readable. However, no benefit in code size or performance
> > as the implementation behind the helper is in fact the same as the one
> > used here.
> > 
> > Maybe more tests should be done to ensure the change is solid, I hope to
> > seek some suggestions from everyone who has any ideas, or this is enough
> > then it's good.
> > 
> > Best regards,
> > I Hsin Cheng
> > ---
> >  kernel/time/clocksource.c | 4 +---
> >  1 file changed, 1 insertion(+), 3 deletions(-)
> > 
> > diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
> > index bb48498ebb5a..12ff0c048570 100644
> > --- a/kernel/time/clocksource.c
> > +++ b/kernel/time/clocksource.c
> > @@ -323,9 +323,7 @@ static void clocksource_verify_choose_cpus(void)
> >  		return;
> >  
> >  	/* Make sure to select at least one CPU other than the current CPU. */
> > -	cpu = cpumask_first(cpu_online_mask);
> > -	if (cpu == smp_processor_id())
> > -		cpu = cpumask_next(cpu, cpu_online_mask);
> > +	cpu = cpumask_first_but(cpu_online_mask, smp_processor_id());
> >  	if (WARN_ON_ONCE(cpu >= nr_cpu_ids))
> >  		return;
> >  	cpumask_set_cpu(cpu, &cpus_chosen);
> > -- 
> > 2.43.0