Re: [PATCH net-next 09/15] net: increase MAX_SKB_FRAGS

Hi Eric,

I love your patch! Yet something to improve:

[auto build test ERROR on net-next/master]

url:    https://github.com/0day-ci/linux/commits/Eric-Dumazet/tcp-BIG-TCP-implementation/20220203-095336
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 52dae93f3bad842c6d585700460a0dea4d70e096
config: hexagon-randconfig-r045-20220130 (https://download.01.org/0day-ci/archive/20220203/202202031315.B425Ipe8-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project a73e4ce6a59b01f0e37037761c1e6889d539d233)
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
        # https://github.com/0day-ci/linux/commit/64ec6b0260be94b2ed90ee6d139591bdbd49c82d
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Eric-Dumazet/tcp-BIG-TCP-implementation/20220203-095336
        git checkout 64ec6b0260be94b2ed90ee6d139591bdbd49c82d
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash kernel/bpf/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <redacted>

All errors (new ones prefixed by >>):

   In file included from kernel/bpf/btf.c:22:

quoted

include/linux/skmsg.h:41:1: error: static_assert failed due to requirement '32 >= (45UL + 1)' "BITS_PER_LONG >= NR_MSG_FRAG_IDS"

   static_assert(BITS_PER_LONG >= NR_MSG_FRAG_IDS);
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/build_bug.h:77:34: note: expanded from macro 'static_assert'
   #define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr)
                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/build_bug.h:78:41: note: expanded from macro '__static_assert'
   #define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
                                           ^              ~~~~
   1 error generated.


vim +41 include/linux/skmsg.h

604326b41a6fb9 Daniel Borkmann 2018-10-13  25  
604326b41a6fb9 Daniel Borkmann 2018-10-13  26  struct sk_msg_sg {
604326b41a6fb9 Daniel Borkmann 2018-10-13  27  	u32				start;
604326b41a6fb9 Daniel Borkmann 2018-10-13  28  	u32				curr;
604326b41a6fb9 Daniel Borkmann 2018-10-13  29  	u32				end;
604326b41a6fb9 Daniel Borkmann 2018-10-13  30  	u32				size;
604326b41a6fb9 Daniel Borkmann 2018-10-13  31  	u32				copybreak;
163ab96b52ae2b Jakub Kicinski  2019-10-06  32  	unsigned long			copy;
031097d9e079e4 Jakub Kicinski  2019-11-27  33  	/* The extra two elements:
031097d9e079e4 Jakub Kicinski  2019-11-27  34  	 * 1) used for chaining the front and sections when the list becomes
031097d9e079e4 Jakub Kicinski  2019-11-27  35  	 *    partitioned (e.g. end < start). The crypto APIs require the
031097d9e079e4 Jakub Kicinski  2019-11-27  36  	 *    chaining;
031097d9e079e4 Jakub Kicinski  2019-11-27  37  	 * 2) to chain tailer SG entries after the message.
d3b18ad31f93d0 John Fastabend  2018-10-13  38  	 */
031097d9e079e4 Jakub Kicinski  2019-11-27  39  	struct scatterlist		data[MAX_MSG_FRAGS + 2];
604326b41a6fb9 Daniel Borkmann 2018-10-13  40  };
031097d9e079e4 Jakub Kicinski  2019-11-27 @41  static_assert(BITS_PER_LONG >= NR_MSG_FRAG_IDS);
604326b41a6fb9 Daniel Borkmann 2018-10-13  42  

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