Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1501555 > unrolled thread

[PATCH] ARM64-cpuinfo: Combine six calls for sequence output into one seq_printf() call in c_show()

Started bySF Markus Elfring <elfring@users.sourceforge.net>
First post2016-10-16 21:10 +0200
Last post2016-10-17 15:20 +0200
Articles 7 — 3 participants

Back to article view | Back to linux.kernel

Contents

  [PATCH] ARM64-cpuinfo: Combine six calls for sequence output into one  seq_printf() call in c_show() SF Markus Elfring <elfring@users.sourceforge.net> - 2016-10-16 21:10 +0200
    Re: [PATCH] ARM64-cpuinfo: Combine six calls for sequence output into  one seq_printf() call in c_show() Matthias Brugger <matthias.bgg@gmail.com> - 2016-10-17 12:00 +0200
    Re: [PATCH] ARM64-cpuinfo: Combine six calls for sequence output  into one seq_printf() call in c_show() Mark Rutland <mark.rutland@arm.com> - 2016-10-17 13:00 +0200
      Re: ARM64-cpuinfo: Combine six calls for sequence output into one  seq_printf() call in c_show() SF Markus Elfring <elfring@users.sourceforge.net> - 2016-10-17 13:40 +0200
        Re: ARM64-cpuinfo: Combine six calls for sequence output into one  seq_printf() call in c_show() Mark Rutland <mark.rutland@arm.com> - 2016-10-17 14:40 +0200
          Re: ARM64-cpuinfo: Combine six calls for sequence output into one  seq_printf() call in c_show() SF Markus Elfring <elfring@users.sourceforge.net> - 2016-10-17 15:00 +0200
            Re: ARM64-cpuinfo: Combine six calls for sequence output into one  seq_printf() call in c_show() Mark Rutland <mark.rutland@arm.com> - 2016-10-17 15:20 +0200

#1501555 — [PATCH] ARM64-cpuinfo: Combine six calls for sequence output into one seq_printf() call in c_show()

FromSF Markus Elfring <elfring@users.sourceforge.net>
Date2016-10-16 21:10 +0200
Subject[PATCH] ARM64-cpuinfo: Combine six calls for sequence output into one seq_printf() call in c_show()
Message-ID<ssYYO-1qy-21@gated-at.bofh.it>
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sun, 16 Oct 2016 20:48:28 +0200

Some data were printed into a sequence by six separate function calls.
Print the same data by a single function call instead.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 arch/arm64/kernel/cpuinfo.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index b3d5b3e..f22687d 100644
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c
@@ -148,14 +148,17 @@ static int c_show(struct seq_file *m, void *v)
 				if (elf_hwcap & (1 << j))
 					seq_printf(m, " %s", hwcap_str[j]);
 		}
-		seq_puts(m, "\n");
-
-		seq_printf(m, "CPU implementer\t: 0x%02x\n",
-			   MIDR_IMPLEMENTOR(midr));
-		seq_printf(m, "CPU architecture: 8\n");
-		seq_printf(m, "CPU variant\t: 0x%x\n", MIDR_VARIANT(midr));
-		seq_printf(m, "CPU part\t: 0x%03x\n", MIDR_PARTNUM(midr));
-		seq_printf(m, "CPU revision\t: %d\n\n", MIDR_REVISION(midr));
+		seq_printf(m,
+			   "\n"
+			   "CPU implementer\t: 0x%02x\n"
+			   "CPU architecture: 8\n"
+			   "CPU variant\t: 0x%x\n"
+			   "CPU part\t: 0x%03x\n"
+			   "CPU revision\t: %d\n\n",
+			   MIDR_IMPLEMENTOR(midr),
+			   MIDR_VARIANT(midr),
+			   MIDR_PARTNUM(midr),
+			   MIDR_REVISION(midr));
 	}
 
 	return 0;
-- 
2.10.1

[toc] | [next] | [standalone]

#1501836 — Re: [PATCH] ARM64-cpuinfo: Combine six calls for sequence output into one seq_printf() call in c_show()

FromMatthias Brugger <matthias.bgg@gmail.com>
Date2016-10-17 12:00 +0200
SubjectRe: [PATCH] ARM64-cpuinfo: Combine six calls for sequence output into one seq_printf() call in c_show()
Message-ID<stcS7-1MH-59@gated-at.bofh.it>
In reply to#1501555

On 16/10/16 21:03, SF Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Sun, 16 Oct 2016 20:48:28 +0200
>
> Some data were printed into a sequence by six separate function calls.
> Print the same data by a single function call instead.
>
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
> ---

Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>

>  arch/arm64/kernel/cpuinfo.c | 19 +++++++++++--------
>  1 file changed, 11 insertions(+), 8 deletions(-)
>
> diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
> index b3d5b3e..f22687d 100644
> --- a/arch/arm64/kernel/cpuinfo.c
> +++ b/arch/arm64/kernel/cpuinfo.c
> @@ -148,14 +148,17 @@ static int c_show(struct seq_file *m, void *v)
>  				if (elf_hwcap & (1 << j))
>  					seq_printf(m, " %s", hwcap_str[j]);
>  		}
> -		seq_puts(m, "\n");
> -
> -		seq_printf(m, "CPU implementer\t: 0x%02x\n",
> -			   MIDR_IMPLEMENTOR(midr));
> -		seq_printf(m, "CPU architecture: 8\n");
> -		seq_printf(m, "CPU variant\t: 0x%x\n", MIDR_VARIANT(midr));
> -		seq_printf(m, "CPU part\t: 0x%03x\n", MIDR_PARTNUM(midr));
> -		seq_printf(m, "CPU revision\t: %d\n\n", MIDR_REVISION(midr));
> +		seq_printf(m,
> +			   "\n"
> +			   "CPU implementer\t: 0x%02x\n"
> +			   "CPU architecture: 8\n"
> +			   "CPU variant\t: 0x%x\n"
> +			   "CPU part\t: 0x%03x\n"
> +			   "CPU revision\t: %d\n\n",
> +			   MIDR_IMPLEMENTOR(midr),
> +			   MIDR_VARIANT(midr),
> +			   MIDR_PARTNUM(midr),
> +			   MIDR_REVISION(midr));
>  	}
>
>  	return 0;
>

[toc] | [prev] | [next] | [standalone]

#1501871 — Re: [PATCH] ARM64-cpuinfo: Combine six calls for sequence output into one seq_printf() call in c_show()

FromMark Rutland <mark.rutland@arm.com>
Date2016-10-17 13:00 +0200
SubjectRe: [PATCH] ARM64-cpuinfo: Combine six calls for sequence output into one seq_printf() call in c_show()
Message-ID<stdOa-2ot-11@gated-at.bofh.it>
In reply to#1501555
On Sun, Oct 16, 2016 at 09:03:52PM +0200, SF Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Sun, 16 Oct 2016 20:48:28 +0200
> 
> Some data were printed into a sequence by six separate function calls.
> Print the same data by a single function call instead.

... why?

Beyond simply having fewer function calls, is there an upside?

This makes it harder to see the relationship between the format strings
and their associated data, and makes the code longer.

Thanks,
Mark.

> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
> ---
>  arch/arm64/kernel/cpuinfo.c | 19 +++++++++++--------
>  1 file changed, 11 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
> index b3d5b3e..f22687d 100644
> --- a/arch/arm64/kernel/cpuinfo.c
> +++ b/arch/arm64/kernel/cpuinfo.c
> @@ -148,14 +148,17 @@ static int c_show(struct seq_file *m, void *v)
>  				if (elf_hwcap & (1 << j))
>  					seq_printf(m, " %s", hwcap_str[j]);
>  		}
> -		seq_puts(m, "\n");
> -
> -		seq_printf(m, "CPU implementer\t: 0x%02x\n",
> -			   MIDR_IMPLEMENTOR(midr));
> -		seq_printf(m, "CPU architecture: 8\n");
> -		seq_printf(m, "CPU variant\t: 0x%x\n", MIDR_VARIANT(midr));
> -		seq_printf(m, "CPU part\t: 0x%03x\n", MIDR_PARTNUM(midr));
> -		seq_printf(m, "CPU revision\t: %d\n\n", MIDR_REVISION(midr));
> +		seq_printf(m,
> +			   "\n"
> +			   "CPU implementer\t: 0x%02x\n"
> +			   "CPU architecture: 8\n"
> +			   "CPU variant\t: 0x%x\n"
> +			   "CPU part\t: 0x%03x\n"
> +			   "CPU revision\t: %d\n\n",
> +			   MIDR_IMPLEMENTOR(midr),
> +			   MIDR_VARIANT(midr),
> +			   MIDR_PARTNUM(midr),
> +			   MIDR_REVISION(midr));
>  	}
>  
>  	return 0;
> -- 
> 2.10.1
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>

[toc] | [prev] | [next] | [standalone]

#1501900 — Re: ARM64-cpuinfo: Combine six calls for sequence output into one seq_printf() call in c_show()

FromSF Markus Elfring <elfring@users.sourceforge.net>
Date2016-10-17 13:40 +0200
SubjectRe: ARM64-cpuinfo: Combine six calls for sequence output into one seq_printf() call in c_show()
Message-ID<steqS-2QN-25@gated-at.bofh.it>
In reply to#1501871
>> Some data were printed into a sequence by six separate function calls.
>> Print the same data by a single function call instead.
> 
> ... why?
> 
> Beyond simply having fewer function calls, is there an upside?

Will it matter to improve run time characteristics at this source code place?


> This makes it harder to see the relationship between the format strings
> and their associated data, and makes the code longer.

Do you prefer an other layout for the passed data so that the increase
of line count in my update suggestion would look differently?

Regards,
Markus

[toc] | [prev] | [next] | [standalone]

#1501938 — Re: ARM64-cpuinfo: Combine six calls for sequence output into one seq_printf() call in c_show()

FromMark Rutland <mark.rutland@arm.com>
Date2016-10-17 14:40 +0200
SubjectRe: ARM64-cpuinfo: Combine six calls for sequence output into one seq_printf() call in c_show()
Message-ID<stfmW-3uj-21@gated-at.bofh.it>
In reply to#1501900
On Mon, Oct 17, 2016 at 01:30:59PM +0200, SF Markus Elfring wrote:
> >> Some data were printed into a sequence by six separate function calls.
> >> Print the same data by a single function call instead.
> > 
> > ... why?
> > 
> > Beyond simply having fewer function calls, is there an upside?
> 
> Will it matter to improve run time characteristics at this source code
> place?

I do not know. If that's not the aim of your existing patch, then I have
no idea what you're trying to achieve.

> > This makes it harder to see the relationship between the format strings
> > and their associated data, and makes the code longer.
> 
> Do you prefer an other layout for the passed data so that the increase
> of line count in my update suggestion would look differently?

I prefer the code as-is. Unless there's a compelling reason to change
it.

Thanks,
Mark.

[toc] | [prev] | [next] | [standalone]

#1501950 — Re: ARM64-cpuinfo: Combine six calls for sequence output into one seq_printf() call in c_show()

FromSF Markus Elfring <elfring@users.sourceforge.net>
Date2016-10-17 15:00 +0200
SubjectRe: ARM64-cpuinfo: Combine six calls for sequence output into one seq_printf() call in c_show()
Message-ID<stfGh-3Br-21@gated-at.bofh.it>
In reply to#1501938
> I prefer the code as-is. Unless there's a compelling reason to change it.

Is the chance for faster log output interesting enough?

Regards,
Markus

[toc] | [prev] | [next] | [standalone]

#1501964 — Re: ARM64-cpuinfo: Combine six calls for sequence output into one seq_printf() call in c_show()

FromMark Rutland <mark.rutland@arm.com>
Date2016-10-17 15:20 +0200
SubjectRe: ARM64-cpuinfo: Combine six calls for sequence output into one seq_printf() call in c_show()
Message-ID<stfZD-3Xh-35@gated-at.bofh.it>
In reply to#1501950
On Mon, Oct 17, 2016 at 02:50:57PM +0200, SF Markus Elfring wrote:
> > I prefer the code as-is. Unless there's a compelling reason to change it.
> 
> Is the chance for faster log output interesting enough?

Is there a particular user that cares today, or are we trying to work
backwards to a rationale?

Thanks,
Mark.

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web