On 04/12/2016 10:09 PM, Boqun Feng wrote:
Hi Waiman,
On Tue, Apr 12, 2016 at 06:54:43PM -0400, Waiman Long wrote:
[...]
+
+/*
+ * Initialize the per-cpu list head
+ */
+int init_pcpu_list_head(struct pcpu_list_head **ppcpu_head)
+{
+ struct pcpu_list_head *pcpu_head = alloc_percpu(struct pcpu_list_head);
+ int cpu;
+
+ if (!pcpu_head)
+ return -ENOMEM;
+
+ for_each_possible_cpu(cpu) {
+ struct pcpu_list_head *head = per_cpu_ptr(pcpu_head, cpu);
+
+ INIT_LIST_HEAD(&head->list);
+ head->lock = __SPIN_LOCK_UNLOCKED(&head->lock);
+ lockdep_set_class(&head->lock,&percpu_list_key);
+ }
+
+ *ppcpu_head = pcpu_head;
+ return 0;
+}
The first time I looked at this patch, I had a hard time to figure out
which "struct pcpu_list_head" pointer is pointing to percpu data(the
pointer could be the parameter for per/this_cpu_ptr()), and which
pointer is pointing to actual structure. For example, 'pcpu_head' and
'head' above are different types of pointers.
So besides improving my code reading skills, I think the following patch
helps ;-) Also it can resolve several splats of sparse when running
'make C=1 lib/'.
Thoughts?
Yes, I think your patch is helpful. I will include your patch in my
patchset.
Thanks,
Longman
