diff options
Diffstat (limited to 'mm/gup.c')
| -rw-r--r-- | mm/gup.c | 200 |
1 files changed, 176 insertions, 24 deletions
@@ -13,6 +13,9 @@ #include <linux/sched/signal.h> #include <linux/rwsem.h> #include <linux/hugetlb.h> +#include <linux/migrate.h> +#include <linux/mm_inline.h> +#include <linux/sched/mm.h> #include <asm/mmu_context.h> #include <asm/pgtable.h> @@ -1126,7 +1129,167 @@ long get_user_pages(unsigned long start, unsigned long nr_pages, } EXPORT_SYMBOL(get_user_pages); +#if defined(CONFIG_FS_DAX) || defined (CONFIG_CMA) + #ifdef CONFIG_FS_DAX +static bool check_dax_vmas(struct vm_area_struct **vmas, long nr_pages) +{ + long i; + struct vm_area_struct *vma_prev = NULL; + + for (i = 0; i < nr_pages; i++) { + struct vm_area_struct *vma = vmas[i]; + + if (vma == vma_prev) + continue; + + vma_prev = vma; + + if (vma_is_fsdax(vma)) + return true; + } + return false; +} +#else +static inline bool check_dax_vmas(struct vm_area_struct **vmas, long nr_pages) +{ + return false; +} +#endif + +#ifdef CONFIG_CMA +static struct page *new_non_cma_page(struct page *page, unsigned long private) +{ + /* + * We want to make sure we allocate the new page from the same node + * as the source page. + */ + int nid = page_to_nid(page); + /* + * Trying to allocate a page for migration. Ignore allocation + * failure warnings. We don't force __GFP_THISNODE here because + * this node here is the node where we have CMA reservation and + * in some case these nodes will have really less non movable + * allocation memory. + */ + gfp_t gfp_mask = GFP_USER | __GFP_NOWARN; + + if (PageHighMem(page)) + gfp_mask |= __GFP_HIGHMEM; + +#ifdef CONFIG_HUGETLB_PAGE + if (PageHuge(page)) { + struct hstate *h = page_hstate(page); + /* + * We don't want to dequeue from the pool because pool pages will + * mostly be from the CMA region. + */ + return alloc_migrate_huge_page(h, gfp_mask, nid, NULL); + } +#endif + if (PageTransHuge(page)) { + struct page *thp; + /* + * ignore allocation failure warnings + */ + gfp_t thp_gfpmask = GFP_TRANSHUGE | __GFP_NOWARN; + + /* + * Remove the movable mask so that we don't allocate from + * CMA area again. + */ + thp_gfpmask &= ~__GFP_MOVABLE; + thp = __alloc_pages_node(nid, thp_gfpmask, HPAGE_PMD_ORDER); + if (!thp) + return NULL; + prep_transhuge_page(thp); + return thp; + } + + return __alloc_pages_node(nid, gfp_mask, 0); +} + +static long check_and_migrate_cma_pages(unsigned long start, long nr_pages, + unsigned int gup_flags, + struct page **pages, + struct vm_area_struct **vmas) +{ + long i; + bool drain_allow = true; + bool migrate_allow = true; + LIST_HEAD(cma_page_list); + +check_again: + for (i = 0; i < nr_pages; i++) { + /* + * If we get a page from the CMA zone, since we are going to + * be pinning these entries, we might as well move them out + * of the CMA zone if possible. + */ + if (is_migrate_cma_page(pages[i])) { + + struct page *head = compound_head(pages[i]); + + if (PageHuge(head)) { + isolate_huge_page(head, &cma_page_list); + } else { + if (!PageLRU(head) && drain_allow) { + lru_add_drain_all(); + drain_allow = false; + } + + if (!isolate_lru_page(head)) { + list_add_tail(&head->lru, &cma_page_list); + mod_node_page_state(page_pgdat(head), + NR_ISOLATED_ANON + + page_is_file_cache(head), + hpage_nr_pages(head)); + } + } + } + } + + if (!list_empty(&cma_page_list)) { + /* + * drop the above get_user_pages reference. + */ + for (i = 0; i < nr_pages; i++) + put_page(pages[i]); + + if (migrate_pages(&cma_page_list, new_non_cma_page, + NULL, 0, MIGRATE_SYNC, MR_CONTIG_RANGE)) { + /* + * some of the pages failed migration. Do get_user_pages + * without migration. + */ + migrate_allow = false; + + if (!list_empty(&cma_page_list)) + putback_movable_pages(&cma_page_list); + } + /* + * We did migrate all the pages, Try to get the page references again + * migrating any new CMA pages which we failed to isolate earlier. + */ + nr_pages = get_user_pages(start, nr_pages, gup_flags, pages, vmas); + if ((nr_pages > 0) && migrate_allow) { + drain_allow = true; + goto check_again; + } + } + + return nr_pages; +} +#else +static inline long check_and_migrate_cma_pages(unsigned long start, long nr_pages, + unsigned int gup_flags, + struct page **pages, + struct vm_area_struct **vmas) +{ + return nr_pages; +} +#endif + /* * This is the same as get_user_pages() in that it assumes we are * operating on the current task's mm, but it goes further to validate @@ -1140,11 +1303,11 @@ EXPORT_SYMBOL(get_user_pages); * Contrast this to iov_iter_get_pages() usages which are transient. */ long get_user_pages_longterm(unsigned long start, unsigned long nr_pages, - unsigned int gup_flags, struct page **pages, - struct vm_area_struct **vmas_arg) + unsigned int gup_flags, struct page **pages, + struct vm_area_struct **vmas_arg) { struct vm_area_struct **vmas = vmas_arg; - struct vm_area_struct *vma_prev = NULL; + unsigned long flags; long rc, i; if (!pages) @@ -1157,31 +1320,20 @@ long get_user_pages_longterm(unsigned long start, unsigned long nr_pages, return -ENOMEM; } + flags = memalloc_nocma_save(); rc = get_user_pages(start, nr_pages, gup_flags, pages, vmas); + memalloc_nocma_restore(flags); + if (rc < 0) + goto out; - for (i = 0; i < rc; i++) { - struct vm_area_struct *vma = vmas[i]; - - if (vma == vma_prev) - continue; - - vma_prev = vma; - - if (vma_is_fsdax(vma)) - break; - } - - /* - * Either get_user_pages() failed, or the vma validation - * succeeded, in either case we don't need to put_page() before - * returning. - */ - if (i >= rc) + if (check_dax_vmas(vmas, rc)) { + for (i = 0; i < rc; i++) + put_page(pages[i]); + rc = -EOPNOTSUPP; goto out; + } - for (i = 0; i < rc; i++) - put_page(pages[i]); - rc = -EOPNOTSUPP; + rc = check_and_migrate_cma_pages(start, rc, gup_flags, pages, vmas); out: if (vmas != vmas_arg) kfree(vmas); |