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Subject: Re: [PATCH] mm/memblock: replace u64 with phys_addr_t where
 appropriate
From:   Joe Perches <joe@perches.com>
To:     Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
        Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        linux-mm <linux-mm@kvack.org>,
        lkml <linux-kernel@vger.kernel.org>,
        Michal Hocko <mhocko@kernel.org>,
        Matthew Wilcox <willy@infradead.org>,
        Linus Torvalds <torvalds@linux-foundation.org>
Date:   Wed, 04 Jul 2018 02:04:44 -0700
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On Wed, 2018-07-04 at 16:23 +0900, Sergey Senozhatsky wrote:
> On (07/04/18 10:03), Mike Rapoport wrote:
> > > %p[Ff] got deprecated by commit 04b8eb7a4ccd9ef9343e2720ccf2a5db8cfe2f67
> > > 
> > > I think it'd be simplest to just convert
> > > all the %pF and %pf uses all at once.
> > > 
> > > $ git grep --name-only "%p[Ff]" | \
> > >   xargs sed -i -e 's/%pF/%pS/' -e 's/%pf/%ps/'
> > > 
> > > and remove the appropriate Documentation bit.
> > > 
> > 
> > Something like this:
> > 
> > From 0d3e7cf494123c2640b9a892160d2e2430787004 Mon Sep 17 00:00:00 2001
> > From: Mike Rapoport <rppt@linux.vnet.ibm.com>
> > Date: Wed, 4 Jul 2018 09:55:50 +0300
> > Subject: [PATCH] treewide: retire '%pF/%pf'
> > 
> > %p[Ff] got deprecated by commit 04b8eb7a4ccd9ef9343e2720ccf2a5db8cfe2f67
> > ("symbol lookup: introduce dereference_symbol_descriptor()")
> > 
> > Replace their uses with %p[Ss] with
> > 
> > $ git grep --name-only "%p[Ff]" | \
> >   xargs sed -i -e 's/%pF/%pS/' -e 's/%pf/%ps/'
> 
> 
> Sorry, NACK on lib/vsprintf.c part
> 
> I definitely didn't want to do this tree-wide pf->ps conversion when
> I introduced my patch set. pf/pF should have never existed, true,
> but I think we must support pf/pF in vsprintf(). Simply because it
> has been around for *far* too long.

And?  checkpatch warns about %p[Ff] uses.

> People tend to develop "habits",
> you know, I'm quite sure ppc/hppa/etc folks still do [and will] use
> pf/pF occasionally.

There's this saying about habits made to be broken.
This is one of those habits.

I'd expect more people probably get the %pS or %ps wrong
than use %pF.

And most people probably look for examples in code and
copy instead of thinking what's correct, so removing old
and deprecated uses from existing code is a good thing.