Re: [PATCH 01/10] x86: assembly, ENTRY for fn, GLOBAL for data

From: hpa@zytor.com
To: Ingo Molnar <mingo@kernel.org>, Thomas Gleixner <tglx@linutronix.de>
Cc: Juergen Gross <jgross@suse.com>, Len Brown <len.brown@intel.com>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	linux-pm@vger.kernel.org,
	Linus Torvalds <torvalds@linux-foundation.org>,
	x86@kernel.org, "Rafael J. Wysocki" <rjw@rjwysocki.net>,
	linux-kernel@vger.kernel.org, mingo@redhat.com,
	Pavel Machek <pavel@ucw.cz>,
	jpoimboe@redhat.com, xen-devel@lists.xenproject.org,
	Boris Ostrovsky <boris.ostrovsky@oracle.com>,
	Jiri Slaby <jslaby@suse.cz>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH 01/10] x86: assembly, ENTRY for fn, GLOBAL for data
Date: Fri, 03 Mar 2017 10:20:11 -0800	[thread overview]
Message-ID: <F37D3EC6-277C-4034-BB6A-B31695ADB358@zytor.com> (raw)
In-Reply-To: <20170301102754.GA13374@gmail.com>

On March 1, 2017 2:27:54 AM PST, Ingo Molnar <mingo@kernel.org> wrote:
>
>* Thomas Gleixner <tglx@linutronix.de> wrote:
>
>> On Wed, 1 Mar 2017, Ingo Molnar wrote:
>> > 
>> > * Jiri Slaby <jslaby@suse.cz> wrote:
>> > 
>> > > This is a start of series to unify use of ENTRY, ENDPROC, GLOBAL,
>END,
>> > > and other macros across x86. When we have all this sorted out,
>this will
>> > > help to inject DWARF unwinding info by objtool later.
>> > > 
>> > > So, let us use the macros this way:
>> > > * ENTRY -- start of a global function
>> > > * ENDPROC -- end of a local/global function
>> > > * GLOBAL -- start of a globally visible data symbol
>> > > * END -- end of local/global data symbol
>> > 
>> > So how about using macro names that actually show the purpose,
>instead of 
>> > importing all the crappy, historic, essentially randomly chosen
>debug symbol macro 
>> > names from the binutils and older kernels?
>> > 
>> > Something sane, like:
>> > 
>> > 	SYM__FUNCTION_START
>> 
>> Sane would be:
>> 
>>      	SYM_FUNCTION_START
>> 
>> The double underscore is just not giving any value.
>
>So the double underscore (at least in my view) has two advantages:
>
>1) it helps separate the prefix from the postfix.
>
>I.e. it's a 'symbols' namespace, and a 'function start', not the
>'start' of a 
>'symbol function'.
>
>2) It also helps easy greppability.
>
>Try this in latest -tip:
>
>  git grep e820__
>
>To see all the E820 API calls - with no false positives!
>
>'git grep e820_' on the other hand is a lot less reliable...
>
>But no strong feelings either way, I just try to sneak in these small
>namespace 
>structure tricks when nobody's looking! ;-)
>
>Thanks,
>
>	Ingo

This seems needlessly verbose to me and clutters the code.

How about:

PROC..ENDPROC, LOCALPROC..ENDPROC and DATA..ENDDATA.  Clear, unambiguous and balanced.

-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.

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