From e21a29552fa3f44ea41c53488875015ae70fd7f8 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Wed, 22 Nov 2017 08:36:00 -0500 Subject: shmem: Convert find_swap_entry to XArray This is a 1:1 conversion. The major part of this patch is converting the test framework from userspace to kernel space and mirroring the algorithm now used in find_swap_entry(). Signed-off-by: Matthew Wilcox --- lib/test_xarray.c | 56 +++++++++++++++++++++++++++++++++++++ mm/shmem.c | 27 +++++++----------- tools/testing/radix-tree/main.c | 61 ----------------------------------------- tools/testing/radix-tree/test.c | 22 --------------- tools/testing/radix-tree/test.h | 1 - 5 files changed, 66 insertions(+), 101 deletions(-) diff --git a/lib/test_xarray.c b/lib/test_xarray.c index 128c6489082f..815daffdd8c9 100644 --- a/lib/test_xarray.c +++ b/lib/test_xarray.c @@ -631,6 +631,61 @@ static noinline void check_find(struct xarray *xa) check_multi_find_2(xa); } +/* See find_swap_entry() in mm/shmem.c */ +static noinline unsigned long xa_find_entry(struct xarray *xa, void *item) +{ + XA_STATE(xas, xa, 0); + unsigned int checked = 0; + void *entry; + + rcu_read_lock(); + xas_for_each(&xas, entry, ULONG_MAX) { + if (xas_retry(&xas, entry)) + continue; + if (entry == item) + break; + checked++; + if ((checked % 4) != 0) + continue; + xas_pause(&xas); + } + rcu_read_unlock(); + + return entry ? xas.xa_index : -1; +} + +static noinline void check_find_entry(struct xarray *xa) +{ +#ifdef CONFIG_XARRAY_MULTI + unsigned int order; + unsigned long offset, index; + + for (order = 0; order < 20; order++) { + for (offset = 0; offset < (1UL << (order + 3)); + offset += (1UL << order)) { + for (index = 0; index < (1UL << (order + 5)); + index += (1UL << order)) { + xa_store_order(xa, index, order, + xa_mk_value(index), GFP_KERNEL); + XA_BUG_ON(xa, xa_load(xa, index) != + xa_mk_value(index)); + XA_BUG_ON(xa, xa_find_entry(xa, + xa_mk_value(index)) != index); + } + XA_BUG_ON(xa, xa_find_entry(xa, xa) != -1); + xa_destroy(xa); + } + } +#endif + + XA_BUG_ON(xa, xa_find_entry(xa, xa) != -1); + xa_store_index(xa, ULONG_MAX, GFP_KERNEL); + XA_BUG_ON(xa, xa_find_entry(xa, xa) != -1); + XA_BUG_ON(xa, xa_find_entry(xa, xa_mk_value(LONG_MAX)) != -1); + xa_erase_index(xa, ULONG_MAX); + XA_BUG_ON(xa, !xa_empty(xa)); +} + static noinline void check_move_small(struct xarray *xa, unsigned long idx) { XA_STATE(xas, xa, 0); @@ -972,6 +1027,7 @@ static int xarray_checks(void) check_multi_store(&array); check_xa_alloc(); check_find(&array); + check_find_entry(&array); check_destroy(&array); check_move(&array); check_create_range(&array); diff --git a/mm/shmem.c b/mm/shmem.c index ce91569426f3..a305529d6b89 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1100,34 +1100,27 @@ static void shmem_evict_inode(struct inode *inode) clear_inode(inode); } -static unsigned long find_swap_entry(struct radix_tree_root *root, void *item) +static unsigned long find_swap_entry(struct xarray *xa, void *item) { - struct radix_tree_iter iter; - void __rcu **slot; - unsigned long found = -1; + XA_STATE(xas, xa, 0); unsigned int checked = 0; + void *entry; rcu_read_lock(); - radix_tree_for_each_slot(slot, root, &iter, 0) { - void *entry = radix_tree_deref_slot(slot); - - if (radix_tree_deref_retry(entry)) { - slot = radix_tree_iter_retry(&iter); + xas_for_each(&xas, entry, ULONG_MAX) { + if (xas_retry(&xas, entry)) continue; - } - if (entry == item) { - found = iter.index; + if (entry == item) break; - } checked++; - if ((checked % 4096) != 0) + if ((checked % XA_CHECK_SCHED) != 0) continue; - slot = radix_tree_iter_resume(slot, &iter); + xas_pause(&xas); cond_resched_rcu(); } - rcu_read_unlock(); - return found; + + return entry ? xas.xa_index : -1; } /* diff --git a/tools/testing/radix-tree/main.c b/tools/testing/radix-tree/main.c index 09deaf4f0959..79589ea570ab 100644 --- a/tools/testing/radix-tree/main.c +++ b/tools/testing/radix-tree/main.c @@ -236,63 +236,6 @@ void copy_tag_check(void) item_kill_tree(&tree); } -static void __locate_check(struct radix_tree_root *tree, unsigned long index, - unsigned order) -{ - struct item *item; - unsigned long index2; - - item_insert_order(tree, index, order); - item = item_lookup(tree, index); - index2 = find_item(tree, item); - if (index != index2) { - printv(2, "index %ld order %d inserted; found %ld\n", - index, order, index2); - abort(); - } -} - -static void __order_0_locate_check(void) -{ - RADIX_TREE(tree, GFP_KERNEL); - int i; - - for (i = 0; i < 50; i++) - __locate_check(&tree, rand() % INT_MAX, 0); - - item_kill_tree(&tree); -} - -static void locate_check(void) -{ - RADIX_TREE(tree, GFP_KERNEL); - unsigned order; - unsigned long offset, index; - - __order_0_locate_check(); - - for (order = 0; order < 20; order++) { - for (offset = 0; offset < (1 << (order + 3)); - offset += (1UL << order)) { - for (index = 0; index < (1UL << (order + 5)); - index += (1UL << order)) { - __locate_check(&tree, index + offset, order); - } - if (find_item(&tree, &tree) != -1) - abort(); - - item_kill_tree(&tree); - } - } - - if (find_item(&tree, &tree) != -1) - abort(); - __locate_check(&tree, -1, 0); - if (find_item(&tree, &tree) != -1) - abort(); - item_kill_tree(&tree); -} - static void single_thread_tests(bool long_run) { int i; @@ -303,10 +246,6 @@ static void single_thread_tests(bool long_run) rcu_barrier(); printv(2, "after multiorder_check: %d allocated, preempt %d\n", nr_allocated, preempt_count); - locate_check(); - rcu_barrier(); - printv(2, "after locate_check: %d allocated, preempt %d\n", - nr_allocated, preempt_count); tag_check(); rcu_barrier(); printv(2, "after tag_check: %d allocated, preempt %d\n", diff --git a/tools/testing/radix-tree/test.c b/tools/testing/radix-tree/test.c index 70ddf964d51c..470419bfd49d 100644 --- a/tools/testing/radix-tree/test.c +++ b/tools/testing/radix-tree/test.c @@ -209,28 +209,6 @@ int tag_tagged_items(struct radix_tree_root *root, pthread_mutex_t *lock, return tagged; } -/* Use the same pattern as find_swap_entry() in mm/shmem.c */ -unsigned long find_item(struct radix_tree_root *root, void *item) -{ - struct radix_tree_iter iter; - void **slot; - unsigned long found = -1; - unsigned long checked = 0; - - radix_tree_for_each_slot(slot, root, &iter, 0) { - if (*slot == item) { - found = iter.index; - break; - } - checked++; - if ((checked % 4) != 0) - continue; - slot = radix_tree_iter_resume(slot, &iter); - } - - return found; -} - static int verify_node(struct radix_tree_node *slot, unsigned int tag, int tagged) { diff --git a/tools/testing/radix-tree/test.h b/tools/testing/radix-tree/test.h index e3dc7a16f09b..9532c18c6cb1 100644 --- a/tools/testing/radix-tree/test.h +++ b/tools/testing/radix-tree/test.h @@ -32,7 +32,6 @@ void item_kill_tree(struct radix_tree_root *root); int tag_tagged_items(struct radix_tree_root *, pthread_mutex_t *, unsigned long start, unsigned long end, unsigned batch, unsigned iftag, unsigned thentag); -unsigned long find_item(struct radix_tree_root *, void *item); void xarray_tests(void); void tag_check(void); -- cgit v1.2.3-59-g8ed1b