Re: [PATCH 10/18] rcu/tree: Maintain separate array for vmalloc ptrs

From: kbuild test robot
Date: Mon Mar 30 2020 - 02:49:37 EST


Hi "Joel,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on rcu/dev]
[also build test ERROR on rcu/rcu/next next-20200327]
[cannot apply to linus/master linux/master v5.6]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url: https://github.com/0day-ci/linux/commits/Joel-Fernandes-Google/kfree_rcu-improvements-for-rcu-dev/20200330-113719
base: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev
config: powerpc-defconfig (attached as .config)
compiler: powerpc64-linux-gcc (GCC) 9.3.0
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
GCC_VERSION=9.3.0 make.cross ARCH=powerpc

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@xxxxxxxxx>

All errors (new ones prefixed by >>):

kernel/rcu/tree.c: In function 'kfree_rcu_work':
>> kernel/rcu/tree.c:2946:4: error: implicit declaration of function 'vfree'; did you mean 'kfree'? [-Werror=implicit-function-declaration]
2946 | vfree(bvhead->records[i]);
| ^~~~~
| kfree
cc1: some warnings being treated as errors

vim +2946 kernel/rcu/tree.c

2884
2885 /*
2886 * This function is invoked in workqueue context after a grace period.
2887 * It frees all the objects queued on ->bhead_free or ->head_free.
2888 */
2889 static void kfree_rcu_work(struct work_struct *work)
2890 {
2891 unsigned long flags;
2892 struct kvfree_rcu_bulk_data *bkhead, *bknext;
2893 struct kvfree_rcu_bulk_data *bvhead, *bvnext;
2894 struct rcu_head *head, *next;
2895 struct kfree_rcu_cpu *krcp;
2896 struct kfree_rcu_cpu_work *krwp;
2897 int i;
2898
2899 krwp = container_of(to_rcu_work(work),
2900 struct kfree_rcu_cpu_work, rcu_work);
2901
2902 krcp = krwp->krcp;
2903 spin_lock_irqsave(&krcp->lock, flags);
2904 /* Channel 1. */
2905 bkhead = krwp->bkvhead_free[0];
2906 krwp->bkvhead_free[0] = NULL;
2907
2908 /* Channel 2. */
2909 bvhead = krwp->bkvhead_free[1];
2910 krwp->bkvhead_free[1] = NULL;
2911
2912 /* Channel 3. */
2913 head = krwp->head_free;
2914 krwp->head_free = NULL;
2915 spin_unlock_irqrestore(&krcp->lock, flags);
2916
2917 /* kmalloc()/kfree() channel. */
2918 for (; bkhead; bkhead = bknext) {
2919 bknext = bkhead->next;
2920
2921 debug_rcu_bhead_unqueue(bkhead);
2922
2923 rcu_lock_acquire(&rcu_callback_map);
2924 trace_rcu_invoke_kfree_bulk_callback(rcu_state.name,
2925 bkhead->nr_records, bkhead->records);
2926
2927 kfree_bulk(bkhead->nr_records, bkhead->records);
2928 rcu_lock_release(&rcu_callback_map);
2929
2930 if (cmpxchg(&krcp->bkvcache[0], NULL, bkhead))
2931 free_page((unsigned long) bkhead);
2932
2933 cond_resched_tasks_rcu_qs();
2934 }
2935
2936 /* vmalloc()/vfree() channel. */
2937 for (; bvhead; bvhead = bvnext) {
2938 bvnext = bvhead->next;
2939
2940 debug_rcu_bhead_unqueue(bvhead);
2941
2942 rcu_lock_acquire(&rcu_callback_map);
2943 for (i = 0; i < bvhead->nr_records; i++) {
2944 trace_rcu_invoke_kvfree_callback(rcu_state.name,
2945 (struct rcu_head *) bvhead->records[i], 0);
> 2946 vfree(bvhead->records[i]);
2947 }
2948 rcu_lock_release(&rcu_callback_map);
2949
2950 if (cmpxchg(&krcp->bkvcache[1], NULL, bvhead))
2951 free_page((unsigned long) bvhead);
2952
2953 cond_resched_tasks_rcu_qs();
2954 }
2955
2956 /*
2957 * This path covers emergency case only due to high
2958 * memory pressure also means low memory condition,
2959 * when we could not allocate a bulk array.
2960 *
2961 * Under that condition an object is queued to the
2962 * list instead.
2963 */
2964 for (; head; head = next) {
2965 unsigned long offset = (unsigned long)head->func;
2966 void *ptr = (void *)head - offset;
2967
2968 next = head->next;
2969 debug_rcu_head_unqueue((struct rcu_head *)ptr);
2970 rcu_lock_acquire(&rcu_callback_map);
2971 trace_rcu_invoke_kvfree_callback(rcu_state.name, head, offset);
2972
2973 if (!WARN_ON_ONCE(!__is_kvfree_rcu_offset(offset)))
2974 kvfree(ptr);
2975
2976 rcu_lock_release(&rcu_callback_map);
2977 cond_resched_tasks_rcu_qs();
2978 }
2979 }
2980

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

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