shmem: Convert shmem_add_to_page_cache to XArray (552446a4) · Commits · 戴 / test

mm/shmem.c

+34 −47

Original line number	Diff line number	Diff line
		@@ -577,9 +577,11 @@ static inline bool is_huge_enabled(struct shmem_sb_info *sbinfo)
		*/
		static int shmem_add_to_page_cache(struct page *page,
		struct address_space *mapping,
		pgoff_t index, void *expected)
		pgoff_t index, void *expected, gfp_t gfp)
		{
		int error, nr = hpage_nr_pages(page);
		XA_STATE_ORDER(xas, &mapping->i_pages, index, compound_order(page));
		unsigned long i = 0;
		unsigned long nr = 1UL << compound_order(page);

		VM_BUG_ON_PAGE(PageTail(page), page);
		VM_BUG_ON_PAGE(index != round_down(index, nr), page);
		@@ -591,46 +593,39 @@ static int shmem_add_to_page_cache(struct page *page,
		page->mapping = mapping;
		page->index = index;

		xa_lock_irq(&mapping->i_pages);
		if (PageTransHuge(page)) {
		void __rcu **results;
		pgoff_t idx;
		int i;

		error = 0;
		if (radix_tree_gang_lookup_slot(&mapping->i_pages,
		&results, &idx, index, 1) &&
		idx < index + HPAGE_PMD_NR) {
		error = -EEXIST;
		}

		if (!error) {
		for (i = 0; i < HPAGE_PMD_NR; i++) {
		error = radix_tree_insert(&mapping->i_pages,
		index + i, page + i);
		VM_BUG_ON(error);
		do {
		void *entry;
		xas_lock_irq(&xas);
		entry = xas_find_conflict(&xas);
		if (entry != expected)
		xas_set_err(&xas, -EEXIST);
		xas_create_range(&xas);
		if (xas_error(&xas))
		goto unlock;
		next:
		xas_store(&xas, page + i);
		if (++i < nr) {
		xas_next(&xas);
		goto next;
		}
		if (PageTransHuge(page)) {
		count_vm_event(THP_FILE_ALLOC);
		__inc_node_page_state(page, NR_SHMEM_THPS);
		}
		} else if (!expected) {
		error = radix_tree_insert(&mapping->i_pages, index, page);
		} else {
		error = shmem_replace_entry(mapping, index, expected, page);
		}

		if (!error) {
		mapping->nrpages += nr;
		if (PageTransHuge(page))
		__inc_node_page_state(page, NR_SHMEM_THPS);
		__mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, nr);
		__mod_node_page_state(page_pgdat(page), NR_SHMEM, nr);
		xa_unlock_irq(&mapping->i_pages);
		} else {
		unlock:
		xas_unlock_irq(&xas);
		} while (xas_nomem(&xas, gfp));

		if (xas_error(&xas)) {
		page->mapping = NULL;
		xa_unlock_irq(&mapping->i_pages);
		page_ref_sub(page, nr);
		return xas_error(&xas);
		}
		return error;

		return 0;
		}

		/*
		@@ -1183,7 +1178,7 @@ static int shmem_unuse_inode(struct shmem_inode_info *info,
		*/
		if (!error)
		error = shmem_add_to_page_cache(*pagep, mapping, index,
		radswap);
		radswap, gfp);
		if (error != -ENOMEM) {
		/*
		* Truncation and eviction use free_swap_and_cache(), which
		@@ -1700,7 +1695,7 @@ repeat:
		false);
		if (!error) {
		error = shmem_add_to_page_cache(page, mapping, index,
		swp_to_radix_entry(swap));
		swp_to_radix_entry(swap), gfp);
		/*
		* We already confirmed swap under page lock, and make
		* no memory allocation here, so usually no possibility
		@@ -1806,13 +1801,8 @@ alloc_nohuge: page = shmem_alloc_and_acct_page(gfp, inode,
		PageTransHuge(page));
		if (error)
		goto unacct;
		error = radix_tree_maybe_preload_order(gfp & GFP_RECLAIM_MASK,
		compound_order(page));
		if (!error) {
		error = shmem_add_to_page_cache(page, mapping, hindex,
		NULL);
		radix_tree_preload_end();
		}
		NULL, gfp & GFP_RECLAIM_MASK);
		if (error) {
		mem_cgroup_cancel_charge(page, memcg,
		PageTransHuge(page));
		@@ -2281,11 +2271,8 @@ static int shmem_mfill_atomic_pte(struct mm_struct *dst_mm,
		if (ret)
		goto out_release;

		ret = radix_tree_maybe_preload(gfp & GFP_RECLAIM_MASK);
		if (!ret) {
		ret = shmem_add_to_page_cache(page, mapping, pgoff, NULL);
		radix_tree_preload_end();
		}
		ret = shmem_add_to_page_cache(page, mapping, pgoff, NULL,
		gfp & GFP_RECLAIM_MASK);
		if (ret)
		goto out_release_uncharge;

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