[kbuild] drivers/regulator/bd718x7-regulator.c:531:8: warning: Excessive padding in 'struct bd718xx_regulator_data' (8 padding bytes, where 0 is optimal).

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* [kbuild] drivers/regulator/bd718x7-regulator.c:531:8: warning: Excessive padding in 'struct bd718xx_regulator_data' (8 padding bytes, where 0 is optimal).
       [not found] <202108172206.9cbgvI53-lkp@intel.com>
@ 2021-08-19  3:24 ` kernel test robot
  2021-08-19  5:34   ` Matti Vaittinen
  0 siblings, 1 reply; 6+ messages in thread
From: kernel test robot @ 2021-08-19  3:24 UTC (permalink / raw)
  To: Cristian Marussi; +Cc: clang-built-linux, kbuild-all, linux-kernel, Mark Brown

[-- Attachment #1: Type: text/plain, Size: 17362 bytes --]

tree: 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   794c7931a2428a656551f2179e6a093233a6e0aa
commit: e7095c35abfc5a5d566941a87434c0fd5ffb570f regulator: core: add 
of_match_full_name boolean flag
date:   9 months ago
:::::: branch date: 12 hours ago
:::::: commit date: 9 months ago
config: arm-randconfig-c002-20210816 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 
44d0a99a12ec7ead4d2f5ef649ba05b40f6d463d)
reproduce (this is a W=1 build):
         wget 
https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross 
-O ~/bin/make.cross
         chmod +x ~/bin/make.cross
         # install arm cross compiling tool for clang build
         # apt-get install binutils-arm-linux-gnueabi
         # 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e7095c35abfc5a5d566941a87434c0fd5ffb570f
         git remote add linus 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
         git fetch --no-tags linus master
         git checkout e7095c35abfc5a5d566941a87434c0fd5ffb570f
         # save the attached .config to linux build tree
         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross 
ARCH=arm clang-analyzer

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


clang-analyzer warnings: (new ones prefixed by >>)
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    2 warnings generated.
    Suppressed 2 warnings (2 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    4 warnings generated.
    Suppressed 4 warnings (4 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    4 warnings generated.
    Suppressed 4 warnings (4 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    4 warnings generated.
    Suppressed 4 warnings (4 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    4 warnings generated.
    Suppressed 4 warnings (4 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    5 warnings generated.
    drivers/regulator/as3722-regulator.c:46:8: warning: Excessive 
padding in 'struct as3722_register_mapping' (14 padding bytes, where 2 
is optimal).
    Optimal fields order:
    name,
    sname,
    n_voltages,
    enable_reg,
    control_reg,
    sleep_ctrl_reg,
    regulator_id,
    vsel_reg,
    vsel_mask,
    enable_mask,
    mode_mask,
    sleep_ctrl_mask,
    consider reordering the fields or adding explicit padding members 
[clang-analyzer-optin.performance.Padding]
    struct as3722_register_mapping {
    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
    drivers/regulator/as3722-regulator.c:46:8: note: Excessive padding 
in 'struct as3722_register_mapping' (14 padding bytes, where 2 is 
optimal). Optimal fields order: name, sname, n_voltages, enable_reg, 
control_reg, sleep_ctrl_reg, regulator_id, vsel_reg, vsel_mask, 
enable_mask, mode_mask, sleep_ctrl_mask, consider reordering the fields 
or adding explicit padding members
    struct as3722_register_mapping {
    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
    Suppressed 4 warnings (4 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    5 warnings generated.
 >> drivers/regulator/bd718x7-regulator.c:531:8: warning: Excessive 
padding in 'struct bd718xx_regulator_data' (8 padding bytes, where 0 is 
optimal).
    Optimal fields order:
    dvs,
    additional_inits,
    additional_init_amnt,
    init,
    desc,
    consider reordering the fields or adding explicit padding members 
[clang-analyzer-optin.performance.Padding]
    struct bd718xx_regulator_data {
    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
    drivers/regulator/bd718x7-regulator.c:531:8: note: Excessive padding 
in 'struct bd718xx_regulator_data' (8 padding bytes, where 0 is 
optimal). Optimal fields order: dvs, additional_inits, 
additional_init_amnt, init, desc, consider reordering the fields or 
adding explicit padding members
    struct bd718xx_regulator_data {
    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
    Suppressed 4 warnings (4 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    2 warnings generated.
    Suppressed 2 warnings (2 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    2 warnings generated.
    Suppressed 2 warnings (2 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    2 warnings generated.
    Suppressed 2 warnings (2 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    2 warnings generated.
    Suppressed 2 warnings (2 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    2 warnings generated.
    Suppressed 2 warnings (2 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    2 warnings generated.
    Suppressed 2 warnings (2 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    4 warnings generated.
    Suppressed 4 warnings (4 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    4 warnings generated.
    Suppressed 4 warnings (4 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    4 warnings generated.
    Suppressed 4 warnings (4 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    4 warnings generated.
    Suppressed 4 warnings (4 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    4 warnings generated.
    Suppressed 4 warnings (4 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    4 warnings generated.
    drivers/gpu/drm/drm_self_refresh_helper.c:85:3: warning: Value 
stored to 'ret' is never read [clang-analyzer-deadcode.DeadStores]
                    ret = -ENOMEM;
                    ^     ~~~~~~~
    drivers/gpu/drm/drm_self_refresh_helper.c:85:3: note: Value stored 
to 'ret' is never read
                    ret = -ENOMEM;
                    ^     ~~~~~~~
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    4 warnings generated.
    drivers/gpu/drm/drm_fb_helper.c:156:24: warning: Value stored to 
'helper' during its initialization is never read 
[clang-analyzer-deadcode.DeadStores]
            struct drm_fb_helper *helper = info->par;
                                  ^~~~~~   ~~~~~~~~~
    drivers/gpu/drm/drm_fb_helper.c:156:24: note: Value stored to 
'helper' during its initialization is never read
            struct drm_fb_helper *helper = info->par;
                                  ^~~~~~   ~~~~~~~~~
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    3 warnings generated.
    Suppressed 3 warnings (3 in non-user code).

vim +531 drivers/regulator/bd718x7-regulator.c

ba08799e90b593 drivers/regulator/bd71837-regulator.c Matti Vaittinen 
2018-05-30  525
494edd266b945f drivers/regulator/bd71837-regulator.c Matti Vaittinen 
2018-09-14  526  struct reg_init {
494edd266b945f drivers/regulator/bd71837-regulator.c Matti Vaittinen 
2018-09-14  527  	unsigned int reg;
494edd266b945f drivers/regulator/bd71837-regulator.c Matti Vaittinen 
2018-09-14  528  	unsigned int mask;
494edd266b945f drivers/regulator/bd71837-regulator.c Matti Vaittinen 
2018-09-14  529  	unsigned int val;
494edd266b945f drivers/regulator/bd71837-regulator.c Matti Vaittinen 
2018-09-14  530  };
494edd266b945f drivers/regulator/bd71837-regulator.c Matti Vaittinen 
2018-09-14 @531  struct bd718xx_regulator_data {
494edd266b945f drivers/regulator/bd71837-regulator.c Matti Vaittinen 
2018-09-14  532  	struct regulator_desc desc;
21b72156ede8b7 drivers/regulator/bd718x7-regulator.c Matti Vaittinen 
2020-01-20  533  	const struct rohm_dvs_config dvs;
494edd266b945f drivers/regulator/bd71837-regulator.c Matti Vaittinen 
2018-09-14  534  	const struct reg_init init;
494edd266b945f drivers/regulator/bd71837-regulator.c Matti Vaittinen 
2018-09-14  535  	const struct reg_init *additional_inits;
494edd266b945f drivers/regulator/bd71837-regulator.c Matti Vaittinen 
2018-09-14  536  	int additional_init_amnt;
494edd266b945f drivers/regulator/bd71837-regulator.c Matti Vaittinen 
2018-09-14  537  };
494edd266b945f drivers/regulator/bd71837-regulator.c Matti Vaittinen 
2018-09-14  538

:::::: The code at line 531 was first introduced by commit
:::::: 494edd266b945f36908184433dd36eda1719cdb0 regulator/mfd: Support 
ROHM BD71847 power management IC

:::::: TO: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
:::::: CC: Mark Brown <broonie@kernel.org>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org


_______________________________________________
kbuild mailing list -- kbuild@lists.01.org
To unsubscribe send an email to kbuild-leave@lists.01.org

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [kbuild] drivers/regulator/bd718x7-regulator.c:531:8: warning: Excessive padding in 'struct bd718xx_regulator_data' (8 padding bytes, where 0 is optimal).
  2021-08-19  3:24 ` [kbuild] drivers/regulator/bd718x7-regulator.c:531:8: warning: Excessive padding in 'struct bd718xx_regulator_data' (8 padding bytes, where 0 is optimal) kernel test robot
@ 2021-08-19  5:34   ` Matti Vaittinen
  2021-08-19 11:37     ` Mark Brown
  2021-08-19 14:49     ` kernel test robot
  0 siblings, 2 replies; 6+ messages in thread
From: Matti Vaittinen @ 2021-08-19  5:34 UTC (permalink / raw)
  To: kernel test robot
  Cc: Cristian Marussi, clang-built-linux, kbuild-all,
	Linux Kernel Mailing List, Mark Brown

Hi,

On Thu, Aug 19, 2021 at 6:26 AM kernel test robot <yujie.liu@intel.com> wrote:
>  >> drivers/regulator/bd718x7-regulator.c:531:8: warning: Excessive
> padding in 'struct bd718xx_regulator_data' (8 padding bytes, where 0 is
> optimal).
>     Optimal fields order:
>     dvs,
>     additional_inits,
>     additional_init_amnt,
>     init,
>     desc,
>     consider reordering the fields or adding explicit padding members
> [clang-analyzer-optin.performance.Padding]
>     struct bd718xx_regulator_data {
>     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
>     drivers/regulator/bd718x7-regulator.c:531:8: note: Excessive padding
> in 'struct bd718xx_regulator_data' (8 padding bytes, where 0 is
> optimal). Optimal fields order: dvs, additional_inits,
> additional_init_amnt, init, desc, consider reordering the fields or
> adding explicit padding members
>     struct bd718xx_regulator_data {
>     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

I don't have a good feeling about these checks. Especially when a
struct is composed of other structs - which may be modified
independently of the code we are looking at here. Any unrelated
addition of a member to any of the structs (well, maybe not the one at
the bottom). I guess fixing all the users of these structs when
something changes would cause quite a churn of changes... What is
expected to be done as a result from these mails?

Best Regards
    -- Matti

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [kbuild] drivers/regulator/bd718x7-regulator.c:531:8: warning: Excessive padding in 'struct bd718xx_regulator_data' (8 padding bytes, where 0 is optimal).
  2021-08-19  5:34   ` Matti Vaittinen
@ 2021-08-19 11:37     ` Mark Brown
  2021-08-19 14:49     ` kernel test robot
  1 sibling, 0 replies; 6+ messages in thread
From: Mark Brown @ 2021-08-19 11:37 UTC (permalink / raw)
  To: Matti Vaittinen
  Cc: kernel test robot, Cristian Marussi, clang-built-linux,
	kbuild-all, Linux Kernel Mailing List

[-- Attachment #1: Type: text/plain, Size: 423 bytes --]

On Thu, Aug 19, 2021 at 08:34:22AM +0300, Matti Vaittinen wrote:

> something changes would cause quite a churn of changes... What is
> expected to be done as a result from these mails?

It's probably fine to ignore them for something like this which is going
to get very few uses in the kernel - it gets a lot more interesting for
something that gets lots of copies allocated since that causes the bloat
to really add up.

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [kbuild] drivers/regulator/bd718x7-regulator.c:531:8: warning: Excessive padding in 'struct bd718xx_regulator_data' (8 padding bytes, where 0 is optimal).
  2021-08-19  5:34   ` Matti Vaittinen
  2021-08-19 11:37     ` Mark Brown
@ 2021-08-19 14:49     ` kernel test robot
  2021-08-19 15:23       ` Mark Brown
  1 sibling, 1 reply; 6+ messages in thread
From: kernel test robot @ 2021-08-19 14:49 UTC (permalink / raw)
  To: Matti Vaittinen, Mark Brown, Cristian Marussi
  Cc: clang-built-linux, kbuild-all, Linux Kernel Mailing List

Hi,

On 8/19/2021 1:34 PM, Matti Vaittinen wrote:
> Hi,
> 
> On Thu, Aug 19, 2021 at 6:26 AM kernel test robot <yujie.liu@intel.com> wrote:
>>   >> drivers/regulator/bd718x7-regulator.c:531:8: warning: Excessive
>> padding in 'struct bd718xx_regulator_data' (8 padding bytes, where 0 is
>> optimal).
>>      Optimal fields order:
>>      dvs,
>>      additional_inits,
>>      additional_init_amnt,
>>      init,
>>      desc,
>>      consider reordering the fields or adding explicit padding members
>> [clang-analyzer-optin.performance.Padding]
>>      struct bd718xx_regulator_data {
>>      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
>>      drivers/regulator/bd718x7-regulator.c:531:8: note: Excessive padding
>> in 'struct bd718xx_regulator_data' (8 padding bytes, where 0 is
>> optimal). Optimal fields order: dvs, additional_inits,
>> additional_init_amnt, init, desc, consider reordering the fields or
>> adding explicit padding members
>>      struct bd718xx_regulator_data {
>>      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
> 
> I don't have a good feeling about these checks. Especially when a
> struct is composed of other structs - which may be modified
> independently of the code we are looking at here. Any unrelated
> addition of a member to any of the structs (well, maybe not the one at
> the bottom). I guess fixing all the users of these structs when
> something changes would cause quite a churn of changes... What is
> expected to be done as a result from these mails?
> 
> Best Regards
>      -- Matti
> 

Sorry for bothering, we'll ignore struct padding warnings next time.

Best Regards,
Yujie Liu

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [kbuild] drivers/regulator/bd718x7-regulator.c:531:8: warning: Excessive padding in 'struct bd718xx_regulator_data' (8 padding bytes, where 0 is optimal).
  2021-08-19 14:49     ` kernel test robot
@ 2021-08-19 15:23       ` Mark Brown
  2021-08-21  4:38         ` kernel test robot
  0 siblings, 1 reply; 6+ messages in thread
From: Mark Brown @ 2021-08-19 15:23 UTC (permalink / raw)
  To: kernel test robot
  Cc: Matti Vaittinen, Cristian Marussi, clang-built-linux, kbuild-all,
	Linux Kernel Mailing List

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On Thu, Aug 19, 2021 at 10:49:13PM +0800, kernel test robot wrote:

> Sorry for bothering, we'll ignore struct padding warnings next time.

I think the warnings are useful, it's just that they're not important
for all structs.  If the struct was getting allocated a lot it could be
pointing out an issue that makes a real difference.  I'm not sure it s
realistic for automation to figure it out for itself so it's better to
send them even if they get ignored a lot.

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [kbuild] drivers/regulator/bd718x7-regulator.c:531:8: warning: Excessive padding in 'struct bd718xx_regulator_data' (8 padding bytes, where 0 is optimal).
  2021-08-19 15:23       ` Mark Brown
@ 2021-08-21  4:38         ` kernel test robot
  0 siblings, 0 replies; 6+ messages in thread
From: kernel test robot @ 2021-08-21  4:38 UTC (permalink / raw)
  To: Mark Brown
  Cc: Matti Vaittinen, Cristian Marussi, clang-built-linux, kbuild-all,
	Linux Kernel Mailing List

Hi Mark,

On 8/19/2021 11:23 PM, Mark Brown wrote:
> On Thu, Aug 19, 2021 at 10:49:13PM +0800, kernel test robot wrote:
> 
>> Sorry for bothering, we'll ignore struct padding warnings next time.
> 
> I think the warnings are useful, it's just that they're not important
> for all structs.  If the struct was getting allocated a lot it could be
> pointing out an issue that makes a real difference.  I'm not sure it s
> realistic for automation to figure it out for itself so it's better to
> send them even if they get ignored a lot.
> 

It's not very practical for automation to figure out how many copies of 
a struct would be created and how much space would be saved in total by 
adjusting struct padding.

For similar warnings in the future, we'll make an effort to do manual 
check first, and send out reports that we think are worthy of notice.

Best Regards,
Yujie Liu

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2021-08-21  4:38 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2021-08-19  3:24 ` [kbuild] drivers/regulator/bd718x7-regulator.c:531:8: warning: Excessive padding in 'struct bd718xx_regulator_data' (8 padding bytes, where 0 is optimal) kernel test robot
2021-08-19  5:34   ` Matti Vaittinen
2021-08-19 11:37     ` Mark Brown
2021-08-19 14:49     ` kernel test robot
2021-08-19 15:23       ` Mark Brown
2021-08-21  4:38         ` kernel test robot

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