questions about ttm_page_alloc.c

[Dan Carpenter]

On Mon, Jul 12, 2010 at 07:12:37PM -0400, Jerome Glisse wrote:
> On 07/12/2010 06:39 PM, Dan Carpenter wrote:
>>     327                  pages_to_free[freed_pages++] = p;
>>     328                  /* We can only remove NUM_PAGES_TO_ALLOC at a time. */
>>     329                  if (freed_pages>= NUM_PAGES_TO_ALLOC) {
>>     330                          /* remove range of pages from the pool */
>>     331                          __list_del(p->lru.prev,&pool->list);
>>
>> 	Why do we use p->lru.prev here when we use &p->lru in other
>> 	places?
>>
>>     332
>>     333                          ttm_pool_update_free_locked(pool, freed_pages);
>>     334                          /**
>>     335                           * Because changing page caching is costly
>>     336                           * we unlock the pool to prevent stalling.
>>

Thanks for answering about the wb vs uncached, but I'm still confused why we use
&p->lru in most places and p->lru.prev in this place.

regards,
dan carpenter