From 3ad75f8a1d9b047989059c67afc38d57161270e9 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Wed, 14 Dec 2016 15:08:20 -0800 Subject: radix tree test suite: handle exceptional entries item_kill_tree() assumes that everything in the tree is a pointer to a struct item, which is annoying when testing the behaviour of exceptional entries. Fix it to delete exceptional entries on the assumption they don't need to be freed. Link: http://lkml.kernel.org/r/1480369871-5271-45-git-send-email-mawilcox@linuxonhyperv.com Signed-off-by: Matthew Wilcox Tested-by: Kirill A. Shutemov Cc: Konstantin Khlebnikov Cc: Ross Zwisler Cc: Matthew Wilcox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- tools/testing/radix-tree/test.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'tools/testing/radix-tree/test.c') diff --git a/tools/testing/radix-tree/test.c b/tools/testing/radix-tree/test.c index a6e8099eaf4f..6f8dafc797ce 100644 --- a/tools/testing/radix-tree/test.c +++ b/tools/testing/radix-tree/test.c @@ -200,9 +200,16 @@ void verify_tag_consistency(struct radix_tree_root *root, unsigned int tag) void item_kill_tree(struct radix_tree_root *root) { + struct radix_tree_iter iter; + void **slot; struct item *items[32]; int nfound; + radix_tree_for_each_slot(slot, root, &iter, 0) { + if (radix_tree_exceptional_entry(*slot)) + radix_tree_delete(root, iter.index); + } + while ((nfound = radix_tree_gang_lookup(root, (void **)items, 0, 32))) { int i; -- cgit v1.2.3 From 101d9607fffefdfc9e3922f0ac9061a61edda1b0 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Wed, 14 Dec 2016 15:08:23 -0800 Subject: radix tree test suite: record order in each item This probably doubles the size of each item allocated by the test suite but it lets us check a few more things, and may be needed for upcoming API changes that require the caller pass in the order of the entry. Link: http://lkml.kernel.org/r/1480369871-5271-46-git-send-email-mawilcox@linuxonhyperv.com Signed-off-by: Matthew Wilcox Tested-by: Kirill A. Shutemov Cc: Konstantin Khlebnikov Cc: Ross Zwisler Cc: Matthew Wilcox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- tools/testing/radix-tree/multiorder.c | 2 +- tools/testing/radix-tree/test.c | 29 +++++++++++++++++++---------- tools/testing/radix-tree/test.h | 6 +++--- 3 files changed, 23 insertions(+), 14 deletions(-) (limited to 'tools/testing/radix-tree/test.c') diff --git a/tools/testing/radix-tree/multiorder.c b/tools/testing/radix-tree/multiorder.c index d1be94667a30..8d5865c95664 100644 --- a/tools/testing/radix-tree/multiorder.c +++ b/tools/testing/radix-tree/multiorder.c @@ -125,7 +125,7 @@ static void multiorder_check(unsigned long index, int order) unsigned long min = index & ~((1UL << order) - 1); unsigned long max = min + (1UL << order); void **slot; - struct item *item2 = item_create(min); + struct item *item2 = item_create(min, order); RADIX_TREE(tree, GFP_KERNEL); printf("Multiorder index %ld, order %d\n", index, order); diff --git a/tools/testing/radix-tree/test.c b/tools/testing/radix-tree/test.c index 6f8dafc797ce..0de548939a2e 100644 --- a/tools/testing/radix-tree/test.c +++ b/tools/testing/radix-tree/test.c @@ -24,21 +24,29 @@ int item_tag_get(struct radix_tree_root *root, unsigned long index, int tag) return radix_tree_tag_get(root, index, tag); } -int __item_insert(struct radix_tree_root *root, struct item *item, - unsigned order) +int __item_insert(struct radix_tree_root *root, struct item *item) { - return __radix_tree_insert(root, item->index, order, item); + return __radix_tree_insert(root, item->index, item->order, item); } int item_insert(struct radix_tree_root *root, unsigned long index) { - return __item_insert(root, item_create(index), 0); + return __item_insert(root, item_create(index, 0)); } int item_insert_order(struct radix_tree_root *root, unsigned long index, unsigned order) { - return __item_insert(root, item_create(index), order); + return __item_insert(root, item_create(index, order)); +} + +void item_sanity(struct item *item, unsigned long index) +{ + unsigned long mask; + assert(!radix_tree_is_internal_node(item)); + assert(item->order < BITS_PER_LONG); + mask = (1UL << item->order) - 1; + assert((item->index | mask) == (index | mask)); } int item_delete(struct radix_tree_root *root, unsigned long index) @@ -46,18 +54,19 @@ int item_delete(struct radix_tree_root *root, unsigned long index) struct item *item = radix_tree_delete(root, index); if (item) { - assert(item->index == index); + item_sanity(item, index); free(item); return 1; } return 0; } -struct item *item_create(unsigned long index) +struct item *item_create(unsigned long index, unsigned int order) { struct item *ret = malloc(sizeof(*ret)); ret->index = index; + ret->order = order; return ret; } @@ -66,8 +75,8 @@ void item_check_present(struct radix_tree_root *root, unsigned long index) struct item *item; item = radix_tree_lookup(root, index); - assert(item != 0); - assert(item->index == index); + assert(item != NULL); + item_sanity(item, index); } struct item *item_lookup(struct radix_tree_root *root, unsigned long index) @@ -80,7 +89,7 @@ void item_check_absent(struct radix_tree_root *root, unsigned long index) struct item *item; item = radix_tree_lookup(root, index); - assert(item == 0); + assert(item == NULL); } /* diff --git a/tools/testing/radix-tree/test.h b/tools/testing/radix-tree/test.h index 215ab77a56e3..423c528aaee9 100644 --- a/tools/testing/radix-tree/test.h +++ b/tools/testing/radix-tree/test.h @@ -5,11 +5,11 @@ struct item { unsigned long index; + unsigned int order; }; -struct item *item_create(unsigned long index); -int __item_insert(struct radix_tree_root *root, struct item *item, - unsigned order); +struct item *item_create(unsigned long index, unsigned int order); +int __item_insert(struct radix_tree_root *root, struct item *item); int item_insert(struct radix_tree_root *root, unsigned long index); int item_insert_order(struct radix_tree_root *root, unsigned long index, unsigned order); -- cgit v1.2.3 From 478922e2b0f41567e4a530771bfb3f693f857d45 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Wed, 14 Dec 2016 15:08:52 -0800 Subject: radix-tree: delete radix_tree_locate_item() This rather complicated function can be better implemented as an iterator. It has only one caller, so move the functionality to the only place that needs it. Update the test suite to follow the same pattern. Link: http://lkml.kernel.org/r/1480369871-5271-56-git-send-email-mawilcox@linuxonhyperv.com Signed-off-by: Matthew Wilcox Acked-by: Konstantin Khlebnikov Tested-by: Kirill A. Shutemov Cc: Ross Zwisler Cc: Matthew Wilcox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/radix-tree.h | 1 - lib/radix-tree.c | 99 ----------------------------------------- mm/shmem.c | 26 ++++++++++- tools/testing/radix-tree/main.c | 8 ++-- tools/testing/radix-tree/test.c | 22 +++++++++ tools/testing/radix-tree/test.h | 2 + 6 files changed, 53 insertions(+), 105 deletions(-) (limited to 'tools/testing/radix-tree/test.c') diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h index 289d007d487b..a13d3f7c6c65 100644 --- a/include/linux/radix-tree.h +++ b/include/linux/radix-tree.h @@ -296,7 +296,6 @@ unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root, unsigned long nr_to_tag, unsigned int fromtag, unsigned int totag); int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag); -unsigned long radix_tree_locate_item(struct radix_tree_root *root, void *item); static inline void radix_tree_preload_end(void) { diff --git a/lib/radix-tree.c b/lib/radix-tree.c index 0a7ac0fb4a65..5bdf1bdbca00 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -1579,105 +1579,6 @@ radix_tree_gang_lookup_tag_slot(struct radix_tree_root *root, void ***results, } EXPORT_SYMBOL(radix_tree_gang_lookup_tag_slot); -#if defined(CONFIG_SHMEM) && defined(CONFIG_SWAP) -#include /* for cond_resched() */ - -struct locate_info { - unsigned long found_index; - bool stop; -}; - -/* - * This linear search is at present only useful to shmem_unuse_inode(). - */ -static unsigned long __locate(struct radix_tree_node *slot, void *item, - unsigned long index, struct locate_info *info) -{ - unsigned long i; - - do { - unsigned int shift = slot->shift; - - for (i = (index >> shift) & RADIX_TREE_MAP_MASK; - i < RADIX_TREE_MAP_SIZE; - i++, index += (1UL << shift)) { - struct radix_tree_node *node = - rcu_dereference_raw(slot->slots[i]); - if (node == RADIX_TREE_RETRY) - goto out; - if (!radix_tree_is_internal_node(node)) { - if (node == item) { - info->found_index = index; - info->stop = true; - goto out; - } - continue; - } - node = entry_to_node(node); - if (is_sibling_entry(slot, node)) - continue; - slot = node; - break; - } - } while (i < RADIX_TREE_MAP_SIZE); - -out: - if ((index == 0) && (i == RADIX_TREE_MAP_SIZE)) - info->stop = true; - return index; -} - -/** - * radix_tree_locate_item - search through radix tree for item - * @root: radix tree root - * @item: item to be found - * - * Returns index where item was found, or -1 if not found. - * Caller must hold no lock (since this time-consuming function needs - * to be preemptible), and must check afterwards if item is still there. - */ -unsigned long radix_tree_locate_item(struct radix_tree_root *root, void *item) -{ - struct radix_tree_node *node; - unsigned long max_index; - unsigned long cur_index = 0; - struct locate_info info = { - .found_index = -1, - .stop = false, - }; - - do { - rcu_read_lock(); - node = rcu_dereference_raw(root->rnode); - if (!radix_tree_is_internal_node(node)) { - rcu_read_unlock(); - if (node == item) - info.found_index = 0; - break; - } - - node = entry_to_node(node); - - max_index = node_maxindex(node); - if (cur_index > max_index) { - rcu_read_unlock(); - break; - } - - cur_index = __locate(node, item, cur_index, &info); - rcu_read_unlock(); - cond_resched(); - } while (!info.stop && cur_index <= max_index); - - return info.found_index; -} -#else -unsigned long radix_tree_locate_item(struct radix_tree_root *root, void *item) -{ - return -1; -} -#endif /* CONFIG_SHMEM && CONFIG_SWAP */ - /** * __radix_tree_delete_node - try to free node after clearing a slot * @root: radix tree root diff --git a/mm/shmem.c b/mm/shmem.c index be11c6dd414a..54287d443806 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1049,6 +1049,30 @@ static void shmem_evict_inode(struct inode *inode) clear_inode(inode); } +static unsigned long find_swap_entry(struct radix_tree_root *root, void *item) +{ + struct radix_tree_iter iter; + void **slot; + unsigned long found = -1; + unsigned int checked = 0; + + rcu_read_lock(); + radix_tree_for_each_slot(slot, root, &iter, 0) { + if (*slot == item) { + found = iter.index; + break; + } + checked++; + if ((checked % 4096) != 0) + continue; + slot = radix_tree_iter_resume(slot, &iter); + cond_resched_rcu(); + } + + rcu_read_unlock(); + return found; +} + /* * If swap found in inode, free it and move page from swapcache to filecache. */ @@ -1062,7 +1086,7 @@ static int shmem_unuse_inode(struct shmem_inode_info *info, int error = 0; radswap = swp_to_radix_entry(swap); - index = radix_tree_locate_item(&mapping->page_tree, radswap); + index = find_swap_entry(&mapping->page_tree, radswap); if (index == -1) return -EAGAIN; /* tell shmem_unuse we found nothing */ diff --git a/tools/testing/radix-tree/main.c b/tools/testing/radix-tree/main.c index 76d9c95aa487..a028dae8a043 100644 --- a/tools/testing/radix-tree/main.c +++ b/tools/testing/radix-tree/main.c @@ -239,7 +239,7 @@ static void __locate_check(struct radix_tree_root *tree, unsigned long index, item_insert_order(tree, index, order); item = item_lookup(tree, index); - index2 = radix_tree_locate_item(tree, item); + index2 = find_item(tree, item); if (index != index2) { printf("index %ld order %d inserted; found %ld\n", index, order, index2); @@ -273,17 +273,17 @@ static void locate_check(void) index += (1UL << order)) { __locate_check(&tree, index + offset, order); } - if (radix_tree_locate_item(&tree, &tree) != -1) + if (find_item(&tree, &tree) != -1) abort(); item_kill_tree(&tree); } } - if (radix_tree_locate_item(&tree, &tree) != -1) + if (find_item(&tree, &tree) != -1) abort(); __locate_check(&tree, -1, 0); - if (radix_tree_locate_item(&tree, &tree) != -1) + if (find_item(&tree, &tree) != -1) abort(); item_kill_tree(&tree); } diff --git a/tools/testing/radix-tree/test.c b/tools/testing/radix-tree/test.c index 0de548939a2e..88bf57f7175e 100644 --- a/tools/testing/radix-tree/test.c +++ b/tools/testing/radix-tree/test.c @@ -151,6 +151,28 @@ void item_full_scan(struct radix_tree_root *root, unsigned long start, assert(nfound == 0); } +/* 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 617416ec3c5e..3d9d1d30da22 100644 --- a/tools/testing/radix-tree/test.h +++ b/tools/testing/radix-tree/test.h @@ -25,6 +25,8 @@ void item_full_scan(struct radix_tree_root *root, unsigned long start, unsigned long nr, int chunk); void item_kill_tree(struct radix_tree_root *root); +unsigned long find_item(struct radix_tree_root *, void *item); + void tag_check(void); void multiorder_checks(void); void iteration_test(void); -- cgit v1.2.3 From 268f42de718128cd0301293177e79c08c38e39a6 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Wed, 14 Dec 2016 15:08:55 -0800 Subject: radix-tree: delete radix_tree_range_tag_if_tagged() This is an exceptionally complicated function with just one caller (tag_pages_for_writeback). We devote a large portion of the runtime of the test suite to testing this one function which has one caller. By introducing the new function radix_tree_iter_tag_set(), we can eliminate all of the complexity while keeping the performance. The caller can now use a fairly standard radix_tree_for_each() loop, and it doesn't need to worry about tricksy things like 'start' wrapping. The test suite continues to spend a large amount of time investigating this function, but now it's testing the underlying primitives such as radix_tree_iter_resume() and the radix_tree_for_each_tagged() iterator which are also used by other parts of the kernel. Link: http://lkml.kernel.org/r/1480369871-5271-57-git-send-email-mawilcox@linuxonhyperv.com Signed-off-by: Matthew Wilcox Tested-by: Kirill A. Shutemov Cc: Konstantin Khlebnikov Cc: Ross Zwisler Cc: Matthew Wilcox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/radix-tree.h | 74 ++++++++++----------- lib/radix-tree.c | 117 ++++++--------------------------- mm/page-writeback.c | 28 +++++--- tools/testing/radix-tree/main.c | 12 ++-- tools/testing/radix-tree/multiorder.c | 13 ++-- tools/testing/radix-tree/regression2.c | 3 +- tools/testing/radix-tree/tag_check.c | 4 +- tools/testing/radix-tree/test.c | 34 ++++++++++ tools/testing/radix-tree/test.h | 3 + 9 files changed, 125 insertions(+), 163 deletions(-) (limited to 'tools/testing/radix-tree/test.c') diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h index a13d3f7c6c65..7a8d2516c73a 100644 --- a/include/linux/radix-tree.h +++ b/include/linux/radix-tree.h @@ -120,6 +120,41 @@ static inline bool radix_tree_empty(struct radix_tree_root *root) return root->rnode == NULL; } +/** + * struct radix_tree_iter - radix tree iterator state + * + * @index: index of current slot + * @next_index: one beyond the last index for this chunk + * @tags: bit-mask for tag-iterating + * @node: node that contains current slot + * @shift: shift for the node that holds our slots + * + * This radix tree iterator works in terms of "chunks" of slots. A chunk is a + * subinterval of slots contained within one radix tree leaf node. It is + * described by a pointer to its first slot and a struct radix_tree_iter + * which holds the chunk's position in the tree and its size. For tagged + * iteration radix_tree_iter also holds the slots' bit-mask for one chosen + * radix tree tag. + */ +struct radix_tree_iter { + unsigned long index; + unsigned long next_index; + unsigned long tags; + struct radix_tree_node *node; +#ifdef CONFIG_RADIX_TREE_MULTIORDER + unsigned int shift; +#endif +}; + +static inline unsigned int iter_shift(const struct radix_tree_iter *iter) +{ +#ifdef CONFIG_RADIX_TREE_MULTIORDER + return iter->shift; +#else + return 0; +#endif +} + /** * Radix-tree synchronization * @@ -283,6 +318,8 @@ void *radix_tree_tag_clear(struct radix_tree_root *root, unsigned long index, unsigned int tag); int radix_tree_tag_get(struct radix_tree_root *root, unsigned long index, unsigned int tag); +void radix_tree_iter_tag_set(struct radix_tree_root *root, + const struct radix_tree_iter *iter, unsigned int tag); unsigned int radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results, unsigned long first_index, unsigned int max_items, @@ -291,10 +328,6 @@ unsigned int radix_tree_gang_lookup_tag_slot(struct radix_tree_root *root, void ***results, unsigned long first_index, unsigned int max_items, unsigned int tag); -unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root, - unsigned long *first_indexp, unsigned long last_index, - unsigned long nr_to_tag, - unsigned int fromtag, unsigned int totag); int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag); static inline void radix_tree_preload_end(void) @@ -302,39 +335,6 @@ static inline void radix_tree_preload_end(void) preempt_enable(); } -/** - * struct radix_tree_iter - radix tree iterator state - * - * @index: index of current slot - * @next_index: one beyond the last index for this chunk - * @tags: bit-mask for tag-iterating - * @shift: shift for the node that holds our slots - * - * This radix tree iterator works in terms of "chunks" of slots. A chunk is a - * subinterval of slots contained within one radix tree leaf node. It is - * described by a pointer to its first slot and a struct radix_tree_iter - * which holds the chunk's position in the tree and its size. For tagged - * iteration radix_tree_iter also holds the slots' bit-mask for one chosen - * radix tree tag. - */ -struct radix_tree_iter { - unsigned long index; - unsigned long next_index; - unsigned long tags; -#ifdef CONFIG_RADIX_TREE_MULTIORDER - unsigned int shift; -#endif -}; - -static inline unsigned int iter_shift(struct radix_tree_iter *iter) -{ -#ifdef CONFIG_RADIX_TREE_MULTIORDER - return iter->shift; -#else - return 0; -#endif -} - #define RADIX_TREE_ITER_TAG_MASK 0x00FF /* tag index in lower byte */ #define RADIX_TREE_ITER_TAGGED 0x0100 /* lookup tagged slots */ #define RADIX_TREE_ITER_CONTIG 0x0200 /* stop at first hole */ diff --git a/lib/radix-tree.c b/lib/radix-tree.c index 5bdf1bdbca00..d1f4ca5b7989 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -219,6 +219,11 @@ radix_tree_find_next_bit(struct radix_tree_node *node, unsigned int tag, return RADIX_TREE_MAP_SIZE; } +static unsigned int iter_offset(const struct radix_tree_iter *iter) +{ + return (iter->index >> iter_shift(iter)) & RADIX_TREE_MAP_MASK; +} + /* * The maximum index which can be stored in a radix tree */ @@ -1014,6 +1019,18 @@ static void node_tag_set(struct radix_tree_root *root, root_tag_set(root, tag); } +/** + * radix_tree_iter_tag_set - set a tag on the current iterator entry + * @root: radix tree root + * @iter: iterator state + * @tag: tag to set + */ +void radix_tree_iter_tag_set(struct radix_tree_root *root, + const struct radix_tree_iter *iter, unsigned int tag) +{ + node_tag_set(root, iter->node, tag, iter_offset(iter)); +} + /** * radix_tree_tag_clear - clear a tag on a radix tree node * @root: radix tree root @@ -1164,6 +1181,7 @@ void ** __radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, if (node == RADIX_TREE_RETRY) return slot; node = entry_to_node(node); + iter->node = node; iter->shift = node->shift; if (flags & RADIX_TREE_ITER_TAGGED) { @@ -1266,6 +1284,7 @@ void **radix_tree_next_chunk(struct radix_tree_root *root, iter->index = index; iter->next_index = maxindex + 1; iter->tags = 1; + iter->node = NULL; __set_iter_shift(iter, 0); return (void **)&root->rnode; } @@ -1308,6 +1327,7 @@ void **radix_tree_next_chunk(struct radix_tree_root *root, /* Update the iterator state */ iter->index = (index &~ node_maxindex(node)) | (offset << node->shift); iter->next_index = (index | node_maxindex(node)) + 1; + iter->node = node; __set_iter_shift(iter, node->shift); if (flags & RADIX_TREE_ITER_TAGGED) @@ -1317,103 +1337,6 @@ void **radix_tree_next_chunk(struct radix_tree_root *root, } EXPORT_SYMBOL(radix_tree_next_chunk); -/** - * radix_tree_range_tag_if_tagged - for each item in given range set given - * tag if item has another tag set - * @root: radix tree root - * @first_indexp: pointer to a starting index of a range to scan - * @last_index: last index of a range to scan - * @nr_to_tag: maximum number items to tag - * @iftag: tag index to test - * @settag: tag index to set if tested tag is set - * - * This function scans range of radix tree from first_index to last_index - * (inclusive). For each item in the range if iftag is set, the function sets - * also settag. The function stops either after tagging nr_to_tag items or - * after reaching last_index. - * - * The tags must be set from the leaf level only and propagated back up the - * path to the root. We must do this so that we resolve the full path before - * setting any tags on intermediate nodes. If we set tags as we descend, then - * we can get to the leaf node and find that the index that has the iftag - * set is outside the range we are scanning. This reults in dangling tags and - * can lead to problems with later tag operations (e.g. livelocks on lookups). - * - * The function returns the number of leaves where the tag was set and sets - * *first_indexp to the first unscanned index. - * WARNING! *first_indexp can wrap if last_index is ULONG_MAX. Caller must - * be prepared to handle that. - */ -unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root, - unsigned long *first_indexp, unsigned long last_index, - unsigned long nr_to_tag, - unsigned int iftag, unsigned int settag) -{ - struct radix_tree_node *node, *child; - unsigned long maxindex; - unsigned long tagged = 0; - unsigned long index = *first_indexp; - - radix_tree_load_root(root, &child, &maxindex); - last_index = min(last_index, maxindex); - if (index > last_index) - return 0; - if (!nr_to_tag) - return 0; - if (!root_tag_get(root, iftag)) { - *first_indexp = last_index + 1; - return 0; - } - if (!radix_tree_is_internal_node(child)) { - *first_indexp = last_index + 1; - root_tag_set(root, settag); - return 1; - } - - node = entry_to_node(child); - - for (;;) { - unsigned offset = radix_tree_descend(node, &child, index); - if (!child) - goto next; - if (!tag_get(node, iftag, offset)) - goto next; - /* Sibling slots never have tags set on them */ - if (radix_tree_is_internal_node(child)) { - node = entry_to_node(child); - continue; - } - - tagged++; - node_tag_set(root, node, settag, offset); - next: - /* Go to next entry in node */ - index = ((index >> node->shift) + 1) << node->shift; - /* Overflow can happen when last_index is ~0UL... */ - if (index > last_index || !index) - break; - offset = (index >> node->shift) & RADIX_TREE_MAP_MASK; - while (offset == 0) { - /* - * We've fully scanned this node. Go up. Because - * last_index is guaranteed to be in the tree, what - * we do below cannot wander astray. - */ - node = node->parent; - offset = (index >> node->shift) & RADIX_TREE_MAP_MASK; - } - if (is_sibling_entry(node, node->slots[offset])) - goto next; - if (tagged >= nr_to_tag) - break; - } - - *first_indexp = index; - - return tagged; -} -EXPORT_SYMBOL(radix_tree_range_tag_if_tagged); - /** * radix_tree_gang_lookup - perform multiple lookup on a radix tree * @root: radix tree root diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 52e2f8e3b472..290e8b7d3181 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2106,18 +2106,26 @@ void tag_pages_for_writeback(struct address_space *mapping, pgoff_t start, pgoff_t end) { #define WRITEBACK_TAG_BATCH 4096 - unsigned long tagged; - - do { - spin_lock_irq(&mapping->tree_lock); - tagged = radix_tree_range_tag_if_tagged(&mapping->page_tree, - &start, end, WRITEBACK_TAG_BATCH, - PAGECACHE_TAG_DIRTY, PAGECACHE_TAG_TOWRITE); + unsigned long tagged = 0; + struct radix_tree_iter iter; + void **slot; + + spin_lock_irq(&mapping->tree_lock); + radix_tree_for_each_tagged(slot, &mapping->page_tree, &iter, start, + PAGECACHE_TAG_DIRTY) { + if (iter.index > end) + break; + radix_tree_iter_tag_set(&mapping->page_tree, &iter, + PAGECACHE_TAG_TOWRITE); + tagged++; + if ((tagged % WRITEBACK_TAG_BATCH) != 0) + continue; + slot = radix_tree_iter_resume(slot, &iter); spin_unlock_irq(&mapping->tree_lock); - WARN_ON_ONCE(tagged > WRITEBACK_TAG_BATCH); cond_resched(); - /* We check 'start' to handle wrapping when end == ~0UL */ - } while (tagged >= WRITEBACK_TAG_BATCH && start); + spin_lock_irq(&mapping->tree_lock); + } + spin_unlock_irq(&mapping->tree_lock); } EXPORT_SYMBOL(tag_pages_for_writeback); diff --git a/tools/testing/radix-tree/main.c b/tools/testing/radix-tree/main.c index a028dae8a043..170175ca4105 100644 --- a/tools/testing/radix-tree/main.c +++ b/tools/testing/radix-tree/main.c @@ -205,8 +205,7 @@ void copy_tag_check(void) } // printf("\ncopying tags...\n"); - cur = start; - tagged = radix_tree_range_tag_if_tagged(&tree, &cur, end, ITEMS, 0, 1); + tagged = tag_tagged_items(&tree, NULL, start, end, ITEMS, 0, 1); // printf("checking copied tags\n"); assert(tagged == count); @@ -214,16 +213,13 @@ void copy_tag_check(void) /* Copy tags in several rounds */ // printf("\ncopying tags...\n"); - cur = start; - do { - tmp = rand() % (count/10+2); - tagged = radix_tree_range_tag_if_tagged(&tree, &cur, end, tmp, 0, 2); - } while (tmp == tagged); + tmp = rand() % (count / 10 + 2); + tagged = tag_tagged_items(&tree, NULL, start, end, tmp, 0, 2); + assert(tagged == count); // printf("%lu %lu %lu\n", tagged, tmp, count); // printf("checking copied tags\n"); check_copied_tags(&tree, start, end, idx, ITEMS, 0, 2); - assert(tagged < tmp); verify_tag_consistency(&tree, 0); verify_tag_consistency(&tree, 1); verify_tag_consistency(&tree, 2); diff --git a/tools/testing/radix-tree/multiorder.c b/tools/testing/radix-tree/multiorder.c index b9be8856d652..86daf23b3509 100644 --- a/tools/testing/radix-tree/multiorder.c +++ b/tools/testing/radix-tree/multiorder.c @@ -26,7 +26,6 @@ static void __multiorder_tag_test(int index, int order) { RADIX_TREE(tree, GFP_KERNEL); int base, err, i; - unsigned long first = 0; /* our canonical entry */ base = index & ~((1 << order) - 1); @@ -60,7 +59,7 @@ static void __multiorder_tag_test(int index, int order) assert(!radix_tree_tag_get(&tree, i, 1)); } - assert(radix_tree_range_tag_if_tagged(&tree, &first, ~0UL, 10, 0, 1) == 1); + assert(tag_tagged_items(&tree, NULL, 0, ~0UL, 10, 0, 1) == 1); assert(radix_tree_tag_clear(&tree, index, 0)); for_each_index(i, base, order) { @@ -251,7 +250,6 @@ void multiorder_tagged_iteration(void) RADIX_TREE(tree, GFP_KERNEL); struct radix_tree_iter iter; void **slot; - unsigned long first = 0; int i, j; printf("Multiorder tagged iteration test\n"); @@ -296,8 +294,8 @@ void multiorder_tagged_iteration(void) } } - radix_tree_range_tag_if_tagged(&tree, &first, ~0UL, - MT_NUM_ENTRIES, 1, 2); + assert(tag_tagged_items(&tree, NULL, 0, ~0UL, TAG_ENTRIES, 1, 2) == + TAG_ENTRIES); for (j = 0; j < 256; j++) { int mask, k; @@ -323,9 +321,8 @@ void multiorder_tagged_iteration(void) } } - first = 1; - radix_tree_range_tag_if_tagged(&tree, &first, ~0UL, - MT_NUM_ENTRIES, 1, 0); + assert(tag_tagged_items(&tree, NULL, 1, ~0UL, MT_NUM_ENTRIES * 2, 1, 0) + == TAG_ENTRIES); i = 0; radix_tree_for_each_tagged(slot, &tree, &iter, 0, 0) { assert(iter.index == tag_index[i]); diff --git a/tools/testing/radix-tree/regression2.c b/tools/testing/radix-tree/regression2.c index 63bf347aaf33..a41325d7a170 100644 --- a/tools/testing/radix-tree/regression2.c +++ b/tools/testing/radix-tree/regression2.c @@ -50,6 +50,7 @@ #include #include "regression.h" +#include "test.h" #define PAGECACHE_TAG_DIRTY 0 #define PAGECACHE_TAG_WRITEBACK 1 @@ -90,7 +91,7 @@ void regression2_test(void) /* 1. */ start = 0; end = max_slots - 2; - radix_tree_range_tag_if_tagged(&mt_tree, &start, end, 1, + tag_tagged_items(&mt_tree, NULL, start, end, 1, PAGECACHE_TAG_DIRTY, PAGECACHE_TAG_TOWRITE); /* 2. */ diff --git a/tools/testing/radix-tree/tag_check.c b/tools/testing/radix-tree/tag_check.c index 186f6e4914e4..ed5f87d1dce2 100644 --- a/tools/testing/radix-tree/tag_check.c +++ b/tools/testing/radix-tree/tag_check.c @@ -23,7 +23,7 @@ __simple_checks(struct radix_tree_root *tree, unsigned long index, int tag) item_tag_set(tree, index, tag); ret = item_tag_get(tree, index, tag); assert(ret != 0); - ret = radix_tree_range_tag_if_tagged(tree, &first, ~0UL, 10, tag, !tag); + ret = tag_tagged_items(tree, NULL, first, ~0UL, 10, tag, !tag); assert(ret == 1); ret = item_tag_get(tree, index, !tag); assert(ret != 0); @@ -320,7 +320,7 @@ static void single_check(void) assert(ret == 0); verify_tag_consistency(&tree, 0); verify_tag_consistency(&tree, 1); - ret = radix_tree_range_tag_if_tagged(&tree, &first, 10, 10, 0, 1); + ret = tag_tagged_items(&tree, NULL, first, 10, 10, 0, 1); assert(ret == 1); ret = radix_tree_gang_lookup_tag(&tree, (void **)items, 0, BATCH, 1); assert(ret == 1); diff --git a/tools/testing/radix-tree/test.c b/tools/testing/radix-tree/test.c index 88bf57f7175e..e5726e373646 100644 --- a/tools/testing/radix-tree/test.c +++ b/tools/testing/radix-tree/test.c @@ -151,6 +151,40 @@ void item_full_scan(struct radix_tree_root *root, unsigned long start, assert(nfound == 0); } +/* Use the same pattern as tag_pages_for_writeback() in mm/page-writeback.c */ +int tag_tagged_items(struct radix_tree_root *root, pthread_mutex_t *lock, + unsigned long start, unsigned long end, unsigned batch, + unsigned iftag, unsigned thentag) +{ + unsigned long tagged = 0; + struct radix_tree_iter iter; + void **slot; + + if (batch == 0) + batch = 1; + + if (lock) + pthread_mutex_lock(lock); + radix_tree_for_each_tagged(slot, root, &iter, start, iftag) { + if (iter.index > end) + break; + radix_tree_iter_tag_set(root, &iter, thentag); + tagged++; + if ((tagged % batch) != 0) + continue; + slot = radix_tree_iter_resume(slot, &iter); + if (lock) { + pthread_mutex_unlock(lock); + rcu_barrier(); + pthread_mutex_lock(lock); + } + } + if (lock) + pthread_mutex_unlock(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) { diff --git a/tools/testing/radix-tree/test.h b/tools/testing/radix-tree/test.h index 3d9d1d30da22..e11e4d260b4e 100644 --- a/tools/testing/radix-tree/test.h +++ b/tools/testing/radix-tree/test.h @@ -25,6 +25,9 @@ void item_full_scan(struct radix_tree_root *root, unsigned long start, unsigned long nr, int chunk); 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 tag_check(void); -- cgit v1.2.3