linux-4.4.1/alloc_pages_current() の履歴(No.1)

• 履歴一覧
• 差分 を表示
• 現在との差分 を表示
• ソース を表示
• linux-4.4.1/alloc_pages_current() へ行く。
  • 1 (2016-03-10 (木) 10:09:46)

参照元†

• linux-4.4.1/alloc_pages()

説明†

• パス: linux-4.4.1/mm/mempolicy.c

• FIXME: これは何？
  • 説明

引数†

• gfp_t gfp
  • linux-4.4.1/gfp_t
• unsigned order

返り値†

• struct page *
  • linux-4.4.1/page

参考†

実装†

/**
 *      alloc_pages_current - Allocate pages.
 *
 *      @gfp:
 *              %GFP_USER   user allocation,
 *              %GFP_KERNEL kernel allocation,
 *              %GFP_HIGHMEM highmem allocation,
 *              %GFP_FS     don't call back into a file system.
 *              %GFP_ATOMIC don't sleep.
 *      @order: Power of two of allocation size in pages. 0 is a single page.
 *
 *      Allocate a page from the kernel page pool.  When not in
 *      interrupt context and apply the current process NUMA policy.
 *      Returns NULL when no page can be allocated.
 *
 *      Don't call cpuset_update_task_memory_state() unless
 *      1) it's ok to take cpuset_sem (can WAIT), and
 *      2) allocating for current task (not interrupt).
 */
struct page *alloc_pages_current(gfp_t gfp, unsigned order)
{
        struct mempolicy *pol = &default_policy;
        struct page *page;
        unsigned int cpuset_mems_cookie;

• • linux-4.4.1/mempolicy
  • linux-4.4.1/default_policy(global)
  • linux-4.4.1/page

        if (!in_interrupt() && !(gfp & __GFP_THISNODE))
                pol = get_task_policy(current);

• • linux-4.4.1/in_interrupt()
  • linux-4.4.1/get_task_policy()

retry_cpuset:
        cpuset_mems_cookie = read_mems_allowed_begin();

• • linux-4.4.1/read_mems_allowed_begin()

        /*
         * No reference counting needed for current->mempolicy
         * nor system default_policy
         */
        if (pol->mode == MPOL_INTERLEAVE)
                page = alloc_page_interleave(gfp, order, interleave_nodes(pol));

• • linux-4.4.1/alloc_page_interleave()
  • linux-4.4.1/interleave_nodes()

        else
                page = __alloc_pages_nodemask(gfp, order,
                                policy_zonelist(gfp, pol, numa_node_id()),
                                policy_nodemask(gfp, pol));

• • linux-4.4.1/__alloc_pages_nodemask()
  • linux-4.4.1/policy_zonelist()
  • linux-4.4.1/numa_node_id()
  • linux-4.4.1/policy_nodemask()

        if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie)))
                goto retry_cpuset;

• • linux-4.4.1/read_mems_allowed_retry()

        return page;
}
EXPORT_SYMBOL(alloc_pages_current);

• • linux-4.4.1/EXPORT_SYMBOL()

コメント†