Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755466AbcK1UFO (ORCPT ); Mon, 28 Nov 2016 15:05:14 -0500 Received: from p3plsmtps2ded02.prod.phx3.secureserver.net ([208.109.80.59]:52500 "EHLO p3plsmtps2ded02.prod.phx3.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754981AbcK1T4o (ORCPT ); Mon, 28 Nov 2016 14:56:44 -0500 x-originating-ip: 72.167.245.219 From: Matthew Wilcox To: linux-kernel@vger.kernel.org, Andrew Morton , Konstantin Khlebnikov , Ross Zwisler Cc: Matthew Wilcox , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, "Kirill A . Shutemov" Subject: [PATCH v3 21/33] radix-tree: Delete radix_tree_locate_item() Date: Mon, 28 Nov 2016 13:50:25 -0800 Message-Id: <1480369871-5271-22-git-send-email-mawilcox@linuxonhyperv.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1480369871-5271-1-git-send-email-mawilcox@linuxonhyperv.com> References: <1480369871-5271-1-git-send-email-mawilcox@linuxonhyperv.com> X-CMAE-Envelope: MS4wfEPIPgdpaMk+7QtiVYs958MhPLzdk5g5DBPz5ldnhDJLByU08okGG1+6880unHSUoeP2iocuDGM+V9od1Jlkr+SdUuaGwd6G4fPpmSTLYNo9cXmLR5rM UQSXRcojYWpDfJ7YmgwSKEw0xEuCo5mx/Qylmj2MeOlmCicaucerDOWuGZSwz4L5K5zzJ1lIwPVuGBddnTutgBR/lPbto7I6IlWtkqMx4hzKXyFaSBU+croC GPF14/IIZw1TMx2m7wycPnTc7em4V08PrdOD77T0reB8LDfQ/IyfKPMO/lFBIdh8+H40YSeLrA96wfrrA6ku5EOldnIdTyCmWhjqS7/CrbaovC77g0PFzSlj 4bHwHs5LxExpLMw6D+7ri+Swi4cJTA9Oc2Ka14haVcJUYHtvpLvlbBLG1BAySnBJQCawi27+kHw1h/RJqIaMZd5A1G83Ruo6wx2vHhPVdCQknBhXcD0= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7683 Lines: 265 From: Matthew Wilcox 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. Signed-off-by: Matthew Wilcox Acked-by: Konstantin Khlebnikov --- 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(-) diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h index 289d007..a13d3f7c6c 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 f8fab01..54ef055 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -1578,105 +1578,6 @@ 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 b9a785e..0dd83bb 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 76d9c95..a028dae 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 0de5489..88bf57f 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 617416e..3d9d1d3 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); -- 2.10.2