Hi Dongli,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on xen-tip/linux-next]
[also build test ERROR on v4.14-rc7 next-20171018]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Dongli-Zhang/xen-time-do-not-decrease-steal-time-after-live-migration-on-xen/20171102-011408
base:   https://git.kernel.org/pub/scm/linux/kernel/git/xen/tip.git linux-next
config: arm64-defconfig (attached as .config)
compiler: aarch64-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=arm64 

All error/warnings (new ones prefixed by >>):

   drivers//xen/time.c: In function 'xen_accumulate_runstate_time':
>> drivers//xen/time.c:92:20: error: implicit declaration of function 'kcalloc' [-Werror=implicit-function-declaration]
      runstate_delta = kcalloc(num_possible_cpus(),
                       ^~~~~~~
>> drivers//xen/time.c:92:18: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
      runstate_delta = kcalloc(num_possible_cpus(),
                     ^
>> drivers//xen/time.c:128:3: error: implicit declaration of function 'kfree' [-Werror=implicit-function-declaration]
      kfree(runstate_delta);
      ^~~~~
   cc1: some warnings being treated as errors

vim +/kcalloc +92 drivers//xen/time.c

    82	
    83	void xen_accumulate_runstate_time(int action)
    84	{
    85		struct vcpu_runstate_info state;
    86		int cpu, i;
    87	
    88		switch (action) {
    89		case -1: /* backup runstate time before suspend */
    90			WARN_ON_ONCE(unlikely(runstate_delta));
    91	
  > 92			runstate_delta = kcalloc(num_possible_cpus(),
    93						 sizeof(*runstate_delta),
    94						 GFP_KERNEL);
    95			if (unlikely(!runstate_delta)) {
    96				pr_alert("%s: failed to allocate runstate_delta\n",
    97					    __func__);
    98				return;
    99			}
   100	
   101			for_each_possible_cpu(cpu) {
   102				xen_get_runstate_snapshot_cpu_delta(&state, cpu);
   103				memcpy(runstate_delta[cpu].time, state.time,
   104				      RUNSTATE_max * sizeof(*runstate_delta[cpu].time));
   105			}
   106	
   107			break;
   108	
   109		case 0: /* backup runstate time after resume */
   110			if (unlikely(!runstate_delta)) {
   111				pr_alert("%s: cannot accumulate runstate time as runstate_delta is NULL\n",
   112					    __func__);
   113				return;
   114			}
   115	
   116			for_each_possible_cpu(cpu) {
   117				for (i = 0; i < RUNSTATE_max; i++)
   118					per_cpu(old_runstate_time, cpu)[i] +=
   119						runstate_delta[cpu].time[i];
   120			}
   121			break;
   122	
   123		default: /* do not accumulate runstate time for checkpointing */
   124			break;
   125		}
   126	
   127		if (action != -1 && runstate_delta) {
 > 128			kfree(runstate_delta);
   129			runstate_delta = NULL;
   130		}
   131	}
   132	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation