RE: [RFC][PATCH 7/7] kref: Implement using refcount_t

From: "Reshetova, Elena" <elena.reshetova@intel.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
	"keescook@chromium.org" <keescook@chromium.org>,
	"will.deacon@arm.com" <will.deacon@arm.com>,
	"arnd@arndb.de" <arnd@arndb.de>,
	"tglx@linutronix.de" <tglx@linutronix.de>,
	"mingo@kernel.org" <mingo@kernel.org>,
	"hpa@zytor.com" <hpa@zytor.com>,
	"dave@progbits.org" <dave@progbits.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [RFC][PATCH 7/7] kref: Implement using refcount_t
Date: Sat, 19 Nov 2016 07:14:08 +0000	[thread overview]
Message-ID: <2236FBA76BA1254E88B949DDB74E612B41C14F79@IRSMSX102.ger.corp.intel.com> (raw)
In-Reply-To: <20161118185351.GW3117@twins.programming.kicks-ass.net>

> On Fri, Nov 18, 2016 at 04:58:52PM +0000, Reshetova, Elena wrote:
> > > Could you please fix you mailer to not unwrap the emails?
> >
> > I wish I understand what you mean by "unwrap"... ?
> 
> Where I always have lines wrapped at 78 characters, but often when I see
> them back in your reply, they're unwrapped and go on forever.
> 
> For some reason your mailer reflows text and mucks with whitespace. I
> know Outlook likes to do this by default.

Ok, I think I managed to fix it. Hope it looks better now. 

> > On Fri, Nov 18, 2016 at 10:47:40AM +0000, Reshetova, Elena wrote:
> 
> > > Oh, and if we define refcount_t to be just atomic_t underneath, what
> > > about the other atomic_long_t, local_t and atomic64_t cases when it is
> > > used for recounting?  I don't feel good just simply changing them to
> > > become atomic_t under refcount_t wrapper.....
> >
> > > Is there anybody using local_t ? That seems 'creative' and highly
> questionable.
> > I am not yet sure about refcounts, but local_t itself is used in couple of places.
> 
> Sure, there's local_t usage, but I'd be very surprised if there's a
> single refcount usage among them.
> 
> > >As for atomic_long_t there's very few, I'd leave them be for now,
> 
> > Ok, I have started a list on them to keep track, but we need to do
> > them also. There is no reason for them not to be refcounts, since so
> > far the ones I see are classical refcounts.
> 
> Well, if you get to tools (cocci script or whatever) to reliably work
> fork atomic_t, then converting the few atomic_long_t's later should be
> trivial.

I am using coccinelle to find all occurrences, but I do the changes only in semi-automated fashion.
Each change needs a proper manual review anyway and often one variable usage is spread between different headers/source files,
so I prefer not to go to full automation and then not being sure what I have done. 