linux-kernel - Re: [PATCH 5/5] Lib: sort.h: replace int size with size

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Date:   Sat, 30 Mar 2019 21:24:18 +0100
From:   Greg KH <gregkh@...uxfoundation.org>
To:     George Spelvin <lkml@....org>
Cc:     st5pub@...dex.ru, adrian.hunter@...el.com,
        ard.biesheuvel@...aro.org, benh@...nel.crashing.org, bp@...en8.de,
        darrick.wong@...cle.com, dchinner@...hat.com, dedekind1@...il.com,
        hpa@...or.com, jlbec@...lplan.org, jpoimboe@...hat.com,
        linux-kernel@...r.kernel.org, linux-snps-arc@...ts.infradead.org,
        mark@...heh.com, mingo@...hat.com, mpe@...erman.id.au,
        naveen.n.rao@...ux.vnet.ibm.com, paulus@...ba.org, richard@....at,
        tglx@...utronix.de, vgupta@...opsys.com, x86@...nel.org
Subject: Re: [PATCH 5/5] Lib: sort.h: replace int size with size_t size in
 the swap function

On Sat, Mar 30, 2019 at 08:15:49PM +0000, George Spelvin wrote:
> On Sat, 30 Mar 2019 at 19:38:26 +0100 greh k-h wrote;
> > On Sat, Mar 30, 2019 at 07:43:53PM +0300, Andrey Abramov wrote:
> >> Replace int type with size_t type of the size argument
> >> in the swap function, also affect all its dependencies.
> >
> > This says _what_ the patch does, but it gives no clue as to _why_ you
> > are doing this.  Neither did your 0/5 patch :(
> >
> > Why make this change?  Nothing afterward depends on it from what I can
> > tell, so why is it needed?
> 
> It's just a minor cleanup, making things less surprising for future
> programmers.  As I wrote in a comment in my patches, using a signed type
> for an object size is definitely a wart; ever since C89 it's expected
> you'd use size_t for the purpose.

You did not say that in this commit log :)

> The connection is that it's a natural consequence of doing a pass over
> every call site.
> 
> You're right it could be dropped from the series harmlessly, but it
> comes from the same work.  But it's all of *three* call sites in the kernel
> which are affected.  Surely that's not an unreasonable amount of churn
> to clean up a wart?

If you think it is a wart, wonderful, yes, let's fix it up.  But again,
a changelog comment should explain _why_ a commit is needed, not _what_
it does, as we can see from the diff itself exactly what the commit
does.

thanks,

greg k-h