From: Joe Perches <joe@perches•com>
To: Alexei Starovoitov <alexei.starovoitov@gmail•com>
Cc: David Laight <David.Laight@aculab•com>,
Quentin Lambert <lambert.quentin@gmail•com>,
"David S. Miller" <davem@davemloft•net>,
Alexey Kuznetsov <kuznet@ms2•inr.ac.ru>,
James Morris <jmorris@namei•org>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6•org>,
Patrick McHardy <kaber@trash•net>,
Thomas Gleixner <tglx@linutronix•de>,
Ingo Molnar <mingo@redhat•com>, "H. Peter Anvin" <hpa@zytor•com>,
"x86@kernel•org" <x86@kernel•org>,
"netdev@vger•kernel.org" <netdev@vger•kernel.org>,
"linux-kernel@vger•kernel.org" <linux-kernel@vger•kernel.org>
Subject: Re: [PATCH] x86: bpf_jit_comp: simplify trivial boolean return
Date: Thu, 04 Dec 2014 10:05:24 -0800 [thread overview]
Message-ID: <1417716324.2721.9.camel@perches.com> (raw)
In-Reply-To: <CAADnVQJawht6+sARaP=s9PyPERjrVOBKiJLrCK0OwnLtzT2CAA@mail.gmail.com>
On Thu, 2014-12-04 at 07:56 -0800, Alexei Starovoitov wrote:
> On Thu, Dec 4, 2014 at 1:26 AM, Joe Perches <joe@perches•com> wrote:
> > On Thu, 2014-11-27 at 10:49 -0800, Joe Perches wrote:
> >> On Thu, 2014-11-27 at 12:25 +0000, David Laight wrote:
> >> > Why the change in data?
> >>
> >> btw: without gcov and using -O2
> >>
> >> $ size arch/x86/net/bpf_jit_comp.o*
> >> text data bss dec hex filename
> >> 9671 4 0 9675 25cb arch/x86/net/bpf_jit_comp.o.new
> >> 10679 4 0 10683 29bb arch/x86/net/bpf_jit_comp.o.old
> >
> > Alexei?
> >
> > Is this 10% reduction in size a good reason to change the code?
>
> yes.
> I believe you're seeing it with gcc 4.9. I wanted to double
> check what 4.6 and 4.7 are doing. If they're not suddenly
> increase code size then resubmit it for inclusion please.
I get these sizes for these compilers
(x86-64, -O2, without profiling)
$ size arch/x86/net/bpf_jit_comp.o*
text data bss dec hex filename
9266 4 0 9270 2436 arch/x86/net/bpf_jit_comp.o.4.4.new
10042 4 0 10046 273e arch/x86/net/bpf_jit_comp.o.4.4.old
9109 4 0 9113 2399 arch/x86/net/bpf_jit_comp.o.4.6.new
9717 4 0 9721 25f9 arch/x86/net/bpf_jit_comp.o.4.6.old
8789 4 0 8793 2259 arch/x86/net/bpf_jit_comp.o.4.7.new
10245 4 0 10249 2809 arch/x86/net/bpf_jit_comp.o.4.7.old
9671 4 0 9675 25cb arch/x86/net/bpf_jit_comp.o.4.9.new
10679 4 0 10683 29bb arch/x86/net/bpf_jit_comp.o.4.9.old
I am a bit surprised by the size variations
next prev parent reply other threads:[~2014-12-04 18:05 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-26 18:34 [PATCH] x86: bpf_jit_comp: simplify trivial boolean return Alexei Starovoitov
2014-11-26 18:41 ` Joe Perches
2014-11-26 20:00 ` Joe Perches
2014-11-27 12:25 ` David Laight
2014-11-27 14:36 ` Quentin Lambert
2014-11-27 18:35 ` Joe Perches
2014-11-27 18:49 ` Joe Perches
2014-12-04 9:26 ` Joe Perches
2014-12-04 15:56 ` Alexei Starovoitov
2014-12-04 18:05 ` Joe Perches [this message]
-- strict thread matches above, loose matches on Subject: below --
2014-12-04 22:44 Alexei Starovoitov
2014-11-26 17:23 Alexei Starovoitov
2014-11-26 18:02 ` Joe Perches
2014-11-26 16:42 Alexei Starovoitov
2014-11-26 16:58 ` Joe Perches
2014-11-26 17:55 ` Daniel Borkmann
2014-11-26 9:18 Quentin Lambert
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