Subject: Re: [PATCH v2] perf/arm-cmn: Add workarounds for CMN-S3 on Graviton5

From: kernel test robot <[email-masked]>
Date: Tue, 5 May 2026 10:31:02 +0800

Hi Aviv,

kernel test robot noticed the following build errors:

[auto build test ERROR on arm-perf/for-next/perf]
[also build test ERROR on soc/for-next linus/master v7.1-rc2 next-20260430]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Aviv-Bakal/perf-arm-cmn-Add-workarounds-for-CMN-S3-on-Graviton5/20260505-011858
base:   https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git for-next/perf
patch link:    https://lore.kernel.org/r/20260504133923.23373-1-avivb%40amazon.com
patch subject: [PATCH v2] perf/arm-cmn: Add workarounds for CMN-S3 on Graviton5
config: i386-buildonly-randconfig-004-20260505 (https://download.01.org/0day-ci/archive/20260505/[email-masked]/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260505/[email-masked]/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <[email-masked]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email-masked]/

All errors (new ones prefixed by >>):

>> drivers/perf/arm-cmn.c:617:15: error: static assertion failed due to requirement 'sizeof(struct arm_cmn_hw_event) <= __builtin_offsetof(struct hw_perf_event, target)': sizeof(struct arm_cmn_hw_event) <= offsetof(struct hw_perf_event, target)
     617 | static_assert(sizeof(struct arm_cmn_hw_event) <= offsetof(struct hw_perf_event, target));
         | ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/build_bug.h:77:50: note: expanded from macro 'static_assert'
      77 | #define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr)
         |                                  ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/build_bug.h:78:56: note: expanded from macro '__static_assert'
      78 | #define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
         |                                                        ^~~~
   drivers/perf/arm-cmn.c:617:47: note: expression evaluates to '104 <= 96'
     617 | static_assert(sizeof(struct arm_cmn_hw_event) <= offsetof(struct hw_perf_event, target));
         | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/build_bug.h:77:50: note: expanded from macro 'static_assert'
      77 | #define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr)
         |                                  ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/build_bug.h:78:56: note: expanded from macro '__static_assert'
      78 | #define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
         |                                                        ^~~~
   1 error generated.

vim +617 drivers/perf/arm-cmn.c

a88fa6c28b867a Robin Murphy   2021-12-03  600  
0ba64770a2f2e5 Robin Murphy   2020-09-18  601  struct arm_cmn_hw_event {
0ba64770a2f2e5 Robin Murphy   2020-09-18  602  	struct arm_cmn_node *dn;
359414b33e00ba Robin Murphy   2024-09-02  603  	u64 dtm_idx[DIV_ROUND_UP(CMN_MAX_NODES_PER_EVENT * 2, 64)];
7633ec2c262fab Robin Murphy   2023-10-20  604  	s8 dtc_idx[CMN_MAX_DTCS];
0ba64770a2f2e5 Robin Murphy   2020-09-18  605  	u8 num_dns;
60d1504070c22c Robin Murphy   2021-12-03  606  	u8 dtm_offset;
4a112585ebe8cb Ilkka Koskinen 2024-06-17  607  
4a112585ebe8cb Ilkka Koskinen 2024-06-17  608  	/*
4a112585ebe8cb Ilkka Koskinen 2024-06-17  609  	 * WP config registers are divided to UP and DOWN events. We need to
4a112585ebe8cb Ilkka Koskinen 2024-06-17  610  	 * keep to track only one of them.
4a112585ebe8cb Ilkka Koskinen 2024-06-17  611  	 */
4a112585ebe8cb Ilkka Koskinen 2024-06-17  612  	DECLARE_BITMAP(wp_idx, CMN_MAX_XPS);
4a112585ebe8cb Ilkka Koskinen 2024-06-17  613  
23760a0144173e Robin Murphy   2022-04-18  614  	bool wide_sel;
65adf71398f5af Robin Murphy   2022-04-18  615  	enum cmn_filter_select filter_sel;
0ba64770a2f2e5 Robin Murphy   2020-09-18  616  };
ff436cee694ee8 Robin Murphy   2024-09-02 @617  static_assert(sizeof(struct arm_cmn_hw_event) <= offsetof(struct hw_perf_event, target));
0ba64770a2f2e5 Robin Murphy   2020-09-18  618  

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