2017-07-05 05:49:43

by Arvind Yadav

[permalink] [raw]
Subject: [PATCH] hwtracing: coresight: constify attribute_group structures.

attribute_groups are not supposed to change at runtime. All functions
working with attribute_groups provided by <linux/sysfs.h> work with const
attribute_group. So mark the non-const structs as const.

File size before:
text data bss dec hex filename
2573 288 296 3157 c55 coresight-etm-perf.o

File size After adding 'const':
text data bss dec hex filename
2613 224 296 3133 c3d coresight-etm-perf.o

Signed-off-by: Arvind Yadav <[email protected]>
---
drivers/hwtracing/coresight/coresight-etm-perf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index 288a423..e97775d 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -60,7 +60,7 @@ struct etm_event_data {
NULL,
};

-static struct attribute_group etm_pmu_format_group = {
+static const struct attribute_group etm_pmu_format_group = {
.name = "format",
.attrs = etm_config_formats_attr,
};
--
1.9.1


2017-07-07 15:29:01

by Mathieu Poirier

[permalink] [raw]
Subject: Re: [PATCH] hwtracing: coresight: constify attribute_group structures.

On 4 July 2017 at 23:49, Arvind Yadav <[email protected]> wrote:
> attribute_groups are not supposed to change at runtime. All functions
> working with attribute_groups provided by <linux/sysfs.h> work with const
> attribute_group. So mark the non-const structs as const.
>
> File size before:
> text data bss dec hex filename
> 2573 288 296 3157 c55 coresight-etm-perf.o
>
> File size After adding 'const':
> text data bss dec hex filename
> 2613 224 296 3133 c3d coresight-etm-perf.o

Hi Arvind,

Did you find this using an automated tool or simply stumbled on it
while reviewing the code? In case of the former it is usually a good
idea to specify which tool was used in the change log.

Thanks,
Mathieu

>
> Signed-off-by: Arvind Yadav <[email protected]>
> ---
> drivers/hwtracing/coresight/coresight-etm-perf.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
> index 288a423..e97775d 100644
> --- a/drivers/hwtracing/coresight/coresight-etm-perf.c
> +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
> @@ -60,7 +60,7 @@ struct etm_event_data {
> NULL,
> };
>
> -static struct attribute_group etm_pmu_format_group = {
> +static const struct attribute_group etm_pmu_format_group = {
> .name = "format",
> .attrs = etm_config_formats_attr,
> };
> --
> 1.9.1
>

2017-07-10 05:10:10

by Arvind Yadav

[permalink] [raw]
Subject: Re: [PATCH] hwtracing: coresight: constify attribute_group structures.

Hi Mathieu,


On Friday 07 July 2017 08:58 PM, Mathieu Poirier wrote:
> On 4 July 2017 at 23:49, Arvind Yadav <[email protected]> wrote:
>> attribute_groups are not supposed to change at runtime. All functions
>> working with attribute_groups provided by <linux/sysfs.h> work with const
>> attribute_group. So mark the non-const structs as const.
>>
>> File size before:
>> text data bss dec hex filename
>> 2573 288 296 3157 c55 coresight-etm-perf.o
>>
>> File size After adding 'const':
>> text data bss dec hex filename
>> 2613 224 296 3133 c3d coresight-etm-perf.o
> Hi Arvind,
>
> Did you find this using an automated tool or simply stumbled on it
> while reviewing the code? In case of the former it is usually a good
> idea to specify which tool was used in the change log.
Automated tools are not able to caught this kind of error.
I have fixed same changes in zram ( commit - dfc8ed8d6a).
Minchan Kim suggested me to change all the places where have not
used const. It's good idea have a tool which can able to detect these
kind of error. I will try to create a tool.
>
> Thanks,
> Mathieu
>
>> Signed-off-by: Arvind Yadav <[email protected]>
>> ---
>> drivers/hwtracing/coresight/coresight-etm-perf.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
>> index 288a423..e97775d 100644
>> --- a/drivers/hwtracing/coresight/coresight-etm-perf.c
>> +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
>> @@ -60,7 +60,7 @@ struct etm_event_data {
>> NULL,
>> };
>>
>> -static struct attribute_group etm_pmu_format_group = {
>> +static const struct attribute_group etm_pmu_format_group = {
>> .name = "format",
>> .attrs = etm_config_formats_attr,
>> };
>> --
>> 1.9.1
>>
Thanks,
~arvind

2017-07-10 17:01:13

by Mathieu Poirier

[permalink] [raw]
Subject: Re: [PATCH] hwtracing: coresight: constify attribute_group structures.

On 4 July 2017 at 23:49, Arvind Yadav <[email protected]> wrote:
> attribute_groups are not supposed to change at runtime. All functions
> working with attribute_groups provided by <linux/sysfs.h> work with const
> attribute_group. So mark the non-const structs as const.
>
> File size before:
> text data bss dec hex filename
> 2573 288 296 3157 c55 coresight-etm-perf.o
>
> File size After adding 'const':
> text data bss dec hex filename
> 2613 224 296 3133 c3d coresight-etm-perf.o
>
> Signed-off-by: Arvind Yadav <[email protected]>
> ---
> drivers/hwtracing/coresight/coresight-etm-perf.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
> index 288a423..e97775d 100644
> --- a/drivers/hwtracing/coresight/coresight-etm-perf.c
> +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
> @@ -60,7 +60,7 @@ struct etm_event_data {
> NULL,
> };
>
> -static struct attribute_group etm_pmu_format_group = {
> +static const struct attribute_group etm_pmu_format_group = {
> .name = "format",
> .attrs = etm_config_formats_attr,
> };
> --
> 1.9.1
>

Applied - thanks.
Mathieu