On Sun, Apr 30, 2017 at 07:41:03PM -0700, Matthew Wilcox wrote:
>On Sun, Apr 30, 2017 at 07:31:51PM +0800, Wei Yang wrote:
>> @@ -2302,7 +2302,11 @@ static bool has_cpu_slab(int cpu, void *info)
>> struct kmem_cache *s = info;
>> struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
>>
>> - return c->page || c->partial;
>> + return c->page
>> +#ifdef CONFIG_SLUB_CPU_PARTIAL
>> + || c->partial
>> +#endif
>> + ;
>> }
>
>No. No way. This is disgusting.
>
Thanks for your comment. I believe you are right.
>The right way to do this is to create an accessor like this:
>
>#ifdef CONFIG_SLUB_CPU_PARTIAL
>#define slub_cpu_partial(c) ((c)->partial)
>#else
>#define slub_cpu_partial(c) 0
Since partial is a pointer to a page, would this be more proper?
#define slub_cpu_partial(c) NULL
>#endif
>
>And then the above becomes:
>
>- return c->page || c->partial;
>+ return c->page || slub_cpu_partial(c);
>
>All the other ifdefs go away, apart from these two:
Looks most of the ifdefs could be replaced by this format, while not all of
them. For example, the sysfs entry.
I would form another version with your suggestion.
Welcome any other comments :-)
>
>> @@ -4980,6 +4990,7 @@ static ssize_t objects_partial_show(struct kmem_cache *s, char *buf)
>> }
>> SLAB_ATTR_RO(objects_partial);
>>
>> +#ifdef CONFIG_SLUB_CPU_PARTIAL
>> static ssize_t slabs_cpu_partial_show(struct kmem_cache *s, char *buf)
>> {
>> int objects = 0;
>> @@ -5010,6 +5021,7 @@ static ssize_t slabs_cpu_partial_show(struct kmem_cache *s, char *buf)
>> return len + sprintf(buf + len, "\n");
>> }
>> SLAB_ATTR_RO(slabs_cpu_partial);
>> +#endif
>>
>> static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
>> {
>> @@ -5364,7 +5376,9 @@ static struct attribute *slab_attrs[] = {
>> &destroy_by_rcu_attr.attr,
>> &shrink_attr.attr,
>> &reserved_attr.attr,
>> +#ifdef CONFIG_SLUB_CPU_PARTIAL
>> &slabs_cpu_partial_attr.attr,
>> +#endif
>> #ifdef CONFIG_SLUB_DEBUG
>> &total_objects_attr.attr,
>> &slabs_attr.attr,
--
Wei Yang
Help you, Help me
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