From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- tools/testing/radix-tree/test.c | 287 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 287 insertions(+) create mode 100644 tools/testing/radix-tree/test.c (limited to 'tools/testing/radix-tree/test.c') diff --git a/tools/testing/radix-tree/test.c b/tools/testing/radix-tree/test.c new file mode 100644 index 000000000..a15d0512e --- /dev/null +++ b/tools/testing/radix-tree/test.c @@ -0,0 +1,287 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include + +#include "test.h" + +struct item * +item_tag_set(struct radix_tree_root *root, unsigned long index, int tag) +{ + return radix_tree_tag_set(root, index, tag); +} + +struct item * +item_tag_clear(struct radix_tree_root *root, unsigned long index, int tag) +{ + return radix_tree_tag_clear(root, index, tag); +} + +int item_tag_get(struct radix_tree_root *root, unsigned long index, int tag) +{ + return radix_tree_tag_get(root, index, tag); +} + +struct item *item_create(unsigned long index, unsigned int order) +{ + struct item *ret = malloc(sizeof(*ret)); + + ret->index = index; + ret->order = order; + return ret; +} + +int item_insert(struct radix_tree_root *root, unsigned long index) +{ + struct item *item = item_create(index, 0); + int err = radix_tree_insert(root, item->index, item); + if (err) + free(item); + return err; +} + +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)); +} + +void item_free(struct item *item, unsigned long index) +{ + item_sanity(item, index); + free(item); +} + +int item_delete(struct radix_tree_root *root, unsigned long index) +{ + struct item *item = radix_tree_delete(root, index); + + if (!item) + return 0; + + item_free(item, index); + return 1; +} + +static void item_free_rcu(struct rcu_head *head) +{ + struct item *item = container_of(head, struct item, rcu_head); + + free(item); +} + +int item_delete_rcu(struct xarray *xa, unsigned long index) +{ + struct item *item = xa_erase(xa, index); + + if (item) { + item_sanity(item, index); + call_rcu(&item->rcu_head, item_free_rcu); + return 1; + } + return 0; +} + +void item_check_present(struct radix_tree_root *root, unsigned long index) +{ + struct item *item; + + item = radix_tree_lookup(root, index); + assert(item != NULL); + item_sanity(item, index); +} + +struct item *item_lookup(struct radix_tree_root *root, unsigned long index) +{ + return radix_tree_lookup(root, index); +} + +void item_check_absent(struct radix_tree_root *root, unsigned long index) +{ + struct item *item; + + item = radix_tree_lookup(root, index); + assert(item == NULL); +} + +/* + * Scan only the passed (start, start+nr] for present items + */ +void item_gang_check_present(struct radix_tree_root *root, + unsigned long start, unsigned long nr, + int chunk, int hop) +{ + struct item *items[chunk]; + unsigned long into; + + for (into = 0; into < nr; ) { + int nfound; + int nr_to_find = chunk; + int i; + + if (nr_to_find > (nr - into)) + nr_to_find = nr - into; + + nfound = radix_tree_gang_lookup(root, (void **)items, + start + into, nr_to_find); + assert(nfound == nr_to_find); + for (i = 0; i < nfound; i++) + assert(items[i]->index == start + into + i); + into += hop; + } +} + +/* + * Scan the entire tree, only expecting present items (start, start+nr] + */ +void item_full_scan(struct radix_tree_root *root, unsigned long start, + unsigned long nr, int chunk) +{ + struct item *items[chunk]; + unsigned long into = 0; + unsigned long this_index = start; + int nfound; + int i; + +// printf("%s(0x%08lx, 0x%08lx, %d)\n", __FUNCTION__, start, nr, chunk); + + while ((nfound = radix_tree_gang_lookup(root, (void **)items, into, + chunk))) { +// printf("At 0x%08lx, nfound=%d\n", into, nfound); + for (i = 0; i < nfound; i++) { + assert(items[i]->index == this_index); + this_index++; + } +// printf("Found 0x%08lx->0x%08lx\n", +// items[0]->index, items[nfound-1]->index); + into = this_index; + } + if (chunk) + assert(this_index == start + nr); + nfound = radix_tree_gang_lookup(root, (void **)items, + this_index, chunk); + assert(nfound == 0); +} + +/* Use the same pattern as tag_pages_for_writeback() in mm/page-writeback.c */ +int tag_tagged_items(struct xarray *xa, unsigned long start, unsigned long end, + unsigned batch, xa_mark_t iftag, xa_mark_t thentag) +{ + XA_STATE(xas, xa, start); + unsigned int tagged = 0; + struct item *item; + + if (batch == 0) + batch = 1; + + xas_lock_irq(&xas); + xas_for_each_marked(&xas, item, end, iftag) { + xas_set_mark(&xas, thentag); + if (++tagged % batch) + continue; + + xas_pause(&xas); + xas_unlock_irq(&xas); + rcu_barrier(); + xas_lock_irq(&xas); + } + xas_unlock_irq(&xas); + + return tagged; +} + +static int verify_node(struct radix_tree_node *slot, unsigned int tag, + int tagged) +{ + int anyset = 0; + int i; + int j; + + slot = entry_to_node(slot); + + /* Verify consistency at this level */ + for (i = 0; i < RADIX_TREE_TAG_LONGS; i++) { + if (slot->tags[tag][i]) { + anyset = 1; + break; + } + } + if (tagged != anyset) { + printf("tag: %u, shift %u, tagged: %d, anyset: %d\n", + tag, slot->shift, tagged, anyset); + for (j = 0; j < RADIX_TREE_MAX_TAGS; j++) { + printf("tag %d: ", j); + for (i = 0; i < RADIX_TREE_TAG_LONGS; i++) + printf("%016lx ", slot->tags[j][i]); + printf("\n"); + } + return 1; + } + assert(tagged == anyset); + + /* Go for next level */ + if (slot->shift > 0) { + for (i = 0; i < RADIX_TREE_MAP_SIZE; i++) + if (slot->slots[i]) + if (verify_node(slot->slots[i], tag, + !!test_bit(i, slot->tags[tag]))) { + printf("Failure at off %d\n", i); + for (j = 0; j < RADIX_TREE_MAX_TAGS; j++) { + printf("tag %d: ", j); + for (i = 0; i < RADIX_TREE_TAG_LONGS; i++) + printf("%016lx ", slot->tags[j][i]); + printf("\n"); + } + return 1; + } + } + return 0; +} + +void verify_tag_consistency(struct radix_tree_root *root, unsigned int tag) +{ + struct radix_tree_node *node = root->xa_head; + if (!radix_tree_is_internal_node(node)) + return; + verify_node(node, tag, !!root_tag_get(root, tag)); +} + +void item_kill_tree(struct xarray *xa) +{ + XA_STATE(xas, xa, 0); + void *entry; + + xas_for_each(&xas, entry, ULONG_MAX) { + if (!xa_is_value(entry)) { + item_free(entry, xas.xa_index); + } + xas_store(&xas, NULL); + } + + assert(xa_empty(xa)); +} + +void tree_verify_min_height(struct radix_tree_root *root, int maxindex) +{ + unsigned shift; + struct radix_tree_node *node = root->xa_head; + if (!radix_tree_is_internal_node(node)) { + assert(maxindex == 0); + return; + } + + node = entry_to_node(node); + assert(maxindex <= node_maxindex(node)); + + shift = node->shift; + if (shift > 0) + assert(maxindex > shift_maxindex(shift - RADIX_TREE_MAP_SHIFT)); + else + assert(maxindex > 0); +} -- cgit v1.3.1