linux-kernel - Re: [PATCH] bitmap: remove explicit newline handling using scnprintf format string

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Message-ID: <20150427163000.GG1499@htj.duckdns.org>
Date:	Mon, 27 Apr 2015 12:30:00 -0400
From:	Tejun Heo <tj@...nel.org>
To:	Sudeep Holla <sudeep.holla@....com>
Cc:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Pawel Moll <Pawel.Moll@....com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	"Peter Zijlstra (Intel)" <peterz@...radead.org>
Subject: Re: [PATCH] bitmap: remove explicit newline handling using scnprintf
 format string

Hello, Sudeep.

On Mon, Apr 27, 2015 at 05:26:16PM +0100, Sudeep Holla wrote:
> Completely agree and in-fact we did discuss that internally too.
> But since this function deals only with page size buffers, we thought
> it's highly unlikely to hit that corner case.

Ah, yeah, right.  It'd probably be worthwhile to document the above in
the description tho.

> >Given that bitmap outputs can be pretty long, this behavior
> >difference has a minute but still non-zero chance of causing something
> >surprising.  There are multiple copies of the above function in arch
> >codes too.
> 
> I assumed that I had consolidated most of them in commit 5aaba36318e5
> ("cpumask: factor out show_cpumap into separate helper function").
> I might have missed, will have a look at it again.

I noticed them while %pb[l] conversion but was too lazy to actually do
anything.  Thanks a lot for actually taking care of them.

> >We prolly want to audit the usages to verify that the
> >passed in buffer is always big enough at which point the above
> >function and its copies can simply be replaced with direct scnprintf()
> >calls.  This function doesn't actually add anything.
>
> Ah, right that would be much simpler.

Yeah, let's get rid of it.

Thanks.

-- 
tejun
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