On 07/22/2010 07:56 AM, Dan Carpenter wrote:
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
This is because it use __list_del to remove a whole part of the list.
/* * Delete a list entry by making the prev/next entries * point to each other. * * This is only for internal list manipulation where we know * the prev/next entries already! */ static inline void __list_del(struct list_head * prev, struct list_head * next) { »·······next->prev = prev; »·······prev->next = next; }
Cheers, Jerome