Hi Alistair,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on tip/locking/core]
[also build test ERROR on linux/master soc/for-next linus/master v5.16-rc3 next-20211203]
[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]

url:    https://github.com/0day-ci/linux/commits/Alistair-Francis/perf-bench-futex-Add-support-for-32-bit-systems-with-64-bit-time_t/20211202-192015
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 4e0d84634445ed550498d613a49ea8f6cfa5e66c
config: i386-allyesconfig (https://download.01.org/0day-ci/archive/20211205/202112051113.Z2TMYJx9-lkp@intel.com/config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
        # https://github.com/0day-ci/linux/commit/710fc0b1a255e93e04efbaccf76f6445db51ff1f
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Alistair-Francis/perf-bench-futex-Add-support-for-32-bit-systems-with-64-bit-time_t/20211202-192015
        git checkout 710fc0b1a255e93e04efbaccf76f6445db51ff1f
        # save the config file to linux build tree
        mkdir build_dir
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash

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 <command-line>:32:
   ./usr/include/linux/futex_syscall.h:33:16: warning: 'struct timespec' declared inside parameter list will not be visible outside of this definition or declaration
      33 |         struct timespec *timeout, __volatile__ uint32_t *uaddr2, int val3)
         |                ^~~~~~~~
   ./usr/include/linux/futex_syscall.h: In function '__kernel_futex_syscall_timeout':

quoted

./usr/include/linux/futex_syscall.h:36:13: error: dereferencing pointer to incomplete type 'struct timespec'

      36 |  if (sizeof(*timeout) != sizeof(struct __kernel_old_timespec)) {
         |             ^~~~~~~~

quoted

./usr/include/linux/futex_syscall.h:37:13: error: implicit declaration of function 'syscall' [-Werror=implicit-function-declaration]

      37 |   int ret = syscall(__NR_futex_time64, uaddr, op, val, timeout, uaddr2, val3);
         |             ^~~~~~~
   cc1: some warnings being treated as errors

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