From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org ([65.50.211.133]:42644 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753283AbdLFAmK (ORCPT ); Tue, 5 Dec 2017 19:42:10 -0500 From: Matthew Wilcox Cc: Matthew Wilcox , Ross Zwisler , Jens Axboe , Rehas Sachdeva , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-nilfs@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 17/73] xarray: Add xas_next and xas_prev Date: Tue, 5 Dec 2017 16:41:03 -0800 Message-Id: <20171206004159.3755-18-willy@infradead.org> In-Reply-To: <20171206004159.3755-1-willy@infradead.org> References: <20171206004159.3755-1-willy@infradead.org> To: unlisted-recipients:; (no To-header on input) Sender: linux-btrfs-owner@vger.kernel.org List-ID: From: Matthew Wilcox These two functions move the xas index by one position, and adjust the rest of the iterator state to match it. This is more efficient than calling xas_set() as it keeps the iterator at the leaves of the tree instead of walking the iterator from the root each time. Signed-off-by: Matthew Wilcox --- include/linux/xarray.h | 71 ++++++++++- lib/xarray.c | 74 ++++++++++++ tools/testing/radix-tree/xarray-test.c | 214 +++++++++++++++++++++++++++++++++ 3 files changed, 357 insertions(+), 2 deletions(-) diff --git a/include/linux/xarray.h b/include/linux/xarray.h index b648c1b93d9f..416708ace115 100644 --- a/include/linux/xarray.h +++ b/include/linux/xarray.h @@ -549,6 +549,12 @@ static inline bool xas_not_node(struct xa_node *node) return (unsigned long)node < 4096; } +/* True if the node represents RESTART or an error */ +static inline bool xas_frozen(struct xa_node *node) +{ + return (unsigned long)node & 1; +} + /* True if the node represents head-of-tree, RESTART or BOUNDS */ static inline bool xas_top(struct xa_node *node) { @@ -664,8 +670,8 @@ static inline bool xa_iter_skip(void *entry) } /* - * node->shift is always 0 for the inline iterators unless we're processing - * a multi-index entry. + * node->shift is always 0 for next_entry and next_tag unless we're processing + * a multi-index entry. It can be non-0 for next/prev, so it's not used there. */ #ifdef CONFIG_RADIX_TREE_MULTIORDER #define xa_node_shift(node) node->shift @@ -673,6 +679,67 @@ static inline bool xa_iter_skip(void *entry) #define xa_node_shift(node) 0 #endif +void *__xas_next(struct xa_state *); +void *__xas_prev(struct xa_state *); + +/** + * xas_prev() - Move iterator to previous index. + * @xas: XArray operation state. + * + * If the @xas was in an error state, it will remain in an error state + * and this function will return %NULL. If the @xas has never been walked, + * it will have the effect of calling xas_load(). Otherwise one will be + * subtracted from the index and the state will be walked to the correct + * location in the array for the next operation. + * + * If the iterator was referencing index 0, this function wraps + * around to %ULONG_MAX. + * + * Return: The entry at the new index. This may be %NULL or an internal + * entry, although it should never be a node entry. + */ +static inline void *xas_prev(struct xa_state *xas) +{ + struct xa_node *node = xas->xa_node; + + if (unlikely(xas_not_node(node) || node->shift || + xas->xa_offset == 0)) + return __xas_prev(xas); + + xas->xa_index--; + xas->xa_offset--; + return xa_entry(xas->xa, node, xas->xa_offset); +} + +/** + * xas_next() - Move state to next index. + * @xas: XArray operation state. + * + * If the @xas was in an error state, it will remain in an error state + * and this function will return %NULL. If the @xas has never been walked, + * it will have the effect of calling xas_load(). Otherwise one will be + * added to the index and the state will be walked to the correct + * location in the array for the next operation. + * + * If the iterator was referencing index %ULONG_MAX, this function wraps + * around to 0. + * + * Return: The entry at the new index. This may be %NULL or an internal + * entry, although it should never be a node entry. + */ +static inline void *xas_next(struct xa_state *xas) +{ + struct xa_node *node = xas->xa_node; + + if (unlikely(xas_not_node(node) || node->shift || + xas->xa_offset == XA_CHUNK_MASK)) + return __xas_next(xas); + + xas->xa_index++; + xas->xa_offset++; + return xa_entry(xas->xa, node, xas->xa_offset); +} + /** * xas_next_entry() - Advance iterator to next present entry. * @xas: XArray operation state. diff --git a/lib/xarray.c b/lib/xarray.c index f3875b251b41..8c6e83d10554 100644 --- a/lib/xarray.c +++ b/lib/xarray.c @@ -799,6 +799,80 @@ void xas_pause(struct xa_state *xas) } EXPORT_SYMBOL_GPL(xas_pause); +/* + * __xas_prev() - Find the previous entry in the XArray. + * @xas: XArray operation state. + * + * Helper function for xas_prev() which handles all the complex cases + * out of line. + */ +void *__xas_prev(struct xa_state *xas) +{ + void *entry; + + if (!xas_frozen(xas->xa_node)) + xas->xa_index--; + if (xas_not_node(xas->xa_node)) + return xas_load(xas); + + if (xas->xa_offset != get_offset(xas->xa_index, xas->xa_node)) + xas->xa_offset--; + + while (xas->xa_offset == 255) { + xas->xa_offset = xas->xa_node->offset - 1; + xas->xa_node = xa_parent(xas->xa, xas->xa_node); + if (!xas->xa_node) + return set_bounds(xas); + } + + for (;;) { + entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset); + if (!xa_is_node(entry)) + return entry; + + xas->xa_node = xa_to_node(entry); + xas->xa_offset = get_offset(xas->xa_index, xas->xa_node); + } +} +EXPORT_SYMBOL_GPL(__xas_prev); + +/* + * __xas_next() - Find the next entry in the XArray. + * @xas: XArray operation state. + * + * Helper function for xas_next() which handles all the complex cases + * out of line. + */ +void *__xas_next(struct xa_state *xas) +{ + void *entry; + + if (!xas_frozen(xas->xa_node)) + xas->xa_index++; + if (xas_not_node(xas->xa_node)) + return xas_load(xas); + + if (xas->xa_offset != get_offset(xas->xa_index, xas->xa_node)) + xas->xa_offset++; + + while (xas->xa_offset == XA_CHUNK_SIZE) { + xas->xa_offset = xas->xa_node->offset + 1; + xas->xa_node = xa_parent(xas->xa, xas->xa_node); + if (!xas->xa_node) + return set_bounds(xas); + } + + for (;;) { + entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset); + if (!xa_is_node(entry)) + return entry; + + xas->xa_node = xa_to_node(entry); + xas->xa_offset = get_offset(xas->xa_index, xas->xa_node); + } +} +EXPORT_SYMBOL_GPL(__xas_next); + /** * xas_find() - Find the next present entry in the XArray. * @xas: XArray operation state. diff --git a/tools/testing/radix-tree/xarray-test.c b/tools/testing/radix-tree/xarray-test.c index cc5d0b7a1edf..0946eef351e2 100644 --- a/tools/testing/radix-tree/xarray-test.c +++ b/tools/testing/radix-tree/xarray-test.c @@ -79,6 +79,104 @@ void check_xas_error(struct xarray *xa) assert(xas.xa_node == XAS_BOUNDS); } +void check_xas_pause(struct xarray *xa) +{ + XA_STATE(xas, xa, 0); + void *entry; + unsigned int seen; + + xa_store(xa, 0, xa_mk_value(0), GFP_KERNEL); + xa_set_tag(xa, 0, XA_TAG_0); + + seen = 0; + rcu_read_lock(); + xas_for_each_tag(&xas, entry, ULONG_MAX, XA_TAG_0) { + if (!seen++) { + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL); + xa_set_tag(xa, 1, XA_TAG_0); + } + } + rcu_read_unlock(); + /* We don't see an entry that was added after we started */ + assert(seen == 1); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + xas_for_each_tag(&xas, entry, ULONG_MAX, XA_TAG_0) { + if (!seen++) + xa_erase(xa, 1); + } + rcu_read_unlock(); + assert(seen == 1); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + xas_for_each(&xas, entry, ULONG_MAX) { + if (!seen++) + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL); + } + rcu_read_unlock(); + assert(seen == 1); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + xas_for_each(&xas, entry, ULONG_MAX) { + if (!seen++) + xa_erase(xa, 1); + } + rcu_read_unlock(); + assert(seen == 1); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + for (entry = xas_load(&xas); entry; entry = xas_next(&xas)) { + if (!seen++) + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL); + } + rcu_read_unlock(); + assert(seen == 2); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + for (entry = xas_load(&xas); entry; entry = xas_next(&xas)) { + if (!seen++) + xa_erase(xa, 1); + } + rcu_read_unlock(); + assert(seen == 1); + + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL); + seen = 0; + xas_set(&xas, 0); + xas_for_each(&xas, entry, ULONG_MAX) { + if (!seen++) + xas_pause(&xas); + } + assert(seen == 2); + + seen = 0; + xas_set(&xas, 0); + for (entry = xas_load(&xas); entry; entry = xas_next(&xas)) { + if (!seen++) + xas_pause(&xas); + } + assert(seen == 2); + + seen = 0; + xas_set(&xas, 0); + xa_set_tag(xa, 1, XA_TAG_0); + xas_for_each_tag(&xas, entry, ULONG_MAX, XA_TAG_0) { + if (!seen++) + xas_pause(&xas); + } + assert(seen == 2); +} + void check_xas_retry(struct xarray *xa) { XA_STATE(xas, xa, 0); @@ -216,9 +314,109 @@ void check_find(struct xarray *xa) assert(index == 16); } +void check_move_small(struct xarray *xa, unsigned long idx) +{ + XA_STATE(xas, xa, 0); + unsigned long i; + + xa_store(xa, 0, xa_mk_value(0), GFP_KERNEL); + xa_store(xa, idx, xa_mk_value(idx), GFP_KERNEL); + + for (i = 0; i < idx * 4; i++) { + void *entry = xas_next(&xas); + if (i <= idx) + assert(xas.xa_node != XAS_RESTART); + assert(xas.xa_index == i); + if (i == 0 || i == idx) + assert(entry == xa_mk_value(i)); + else + assert(entry == NULL); + } + xas_next(&xas); + assert(xas.xa_index == i); + + do { + void *entry = xas_prev(&xas); + i--; + if (i <= idx) + assert(xas.xa_node != XAS_RESTART); + assert(xas.xa_index == i); + if (i == 0 || i == idx) + assert(entry == xa_mk_value(i)); + else + assert(entry == NULL); + } while (i > 0); + + xas_set(&xas, ULONG_MAX); + assert(xas_next(&xas) == NULL); + assert(xas.xa_index == ULONG_MAX); + assert(xas_next(&xas) == xa_mk_value(0)); + assert(xas.xa_index == 0); + assert(xas_prev(&xas) == NULL); + assert(xas.xa_index == ULONG_MAX); +} + +void check_move(struct xarray *xa) +{ + XA_STATE(xas, xa, (1 << 16) - 1); + unsigned long i; + + for (i = 0; i < (1 << 16); i++) { + xa_store(xa, i, xa_mk_value(i), GFP_KERNEL); + } + + do { + void *entry = xas_prev(&xas); + i--; + assert(entry == xa_mk_value(i)); + assert(i == xas.xa_index); + } while (i != 0); + + assert(xas_prev(&xas) == NULL); + assert(xas.xa_index == ULONG_MAX); + + do { + void *entry = xas_next(&xas); + assert(entry == xa_mk_value(i)); + assert(i == xas.xa_index); + i++; + } while (i < (1 << 16)); + + for (i = (1 << 8); i < (1 << 15); i++) { + xa_erase(xa, i); + } + + i = xas.xa_index; + + do { + void *entry = xas_prev(&xas); + i--; + if ((i < (1 << 8)) || (i >= (1 << 15))) + assert(entry == xa_mk_value(i)); + else + assert(entry == NULL); + assert(i == xas.xa_index); + } while (i != 0); + + assert(xas_prev(&xas) == NULL); + assert(xas.xa_index == ULONG_MAX); + + do { + void *entry = xas_next(&xas); + if ((i < (1 << 8)) || (i >= (1 << 15))) + assert(entry == xa_mk_value(i)); + else + assert(entry == NULL); + assert(i == xas.xa_index); + i++; + } while (i < (1 << 16)); + +} + void xarray_checks(void) { DEFINE_XARRAY(array); + unsigned long i; check_xa_tag(&array); item_kill_tree(&array); @@ -229,6 +427,9 @@ void xarray_checks(void) check_xas_retry(&array); item_kill_tree(&array); + check_xas_pause(&array); + item_kill_tree(&array); + check_xa_load(&array); item_kill_tree(&array); @@ -240,6 +441,19 @@ void xarray_checks(void) check_find(&array); item_kill_tree(&array); + + for (i = 0; i < 16; i++) { + check_move_small(&array, 1UL << i); + item_kill_tree(&array); + } + + for (i = 2; i < 16; i++) { + check_move_small(&array, (1UL << i) - 1); + item_kill_tree(&array); + } + + check_move(&array); + item_kill_tree(&array); } int __weak main(void) -- 2.15.0 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Matthew Wilcox To: Cc: Matthew Wilcox , Ross Zwisler , Jens Axboe , Rehas Sachdeva , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-nilfs@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 17/73] xarray: Add xas_next and xas_prev Date: Tue, 5 Dec 2017 16:41:03 -0800 Message-Id: <20171206004159.3755-18-willy@infradead.org> In-Reply-To: <20171206004159.3755-1-willy@infradead.org> References: <20171206004159.3755-1-willy@infradead.org> Sender: owner-linux-mm@kvack.org List-ID: From: Matthew Wilcox These two functions move the xas index by one position, and adjust the rest of the iterator state to match it. This is more efficient than calling xas_set() as it keeps the iterator at the leaves of the tree instead of walking the iterator from the root each time. Signed-off-by: Matthew Wilcox --- include/linux/xarray.h | 71 ++++++++++- lib/xarray.c | 74 ++++++++++++ tools/testing/radix-tree/xarray-test.c | 214 +++++++++++++++++++++++++++++++++ 3 files changed, 357 insertions(+), 2 deletions(-) diff --git a/include/linux/xarray.h b/include/linux/xarray.h index b648c1b93d9f..416708ace115 100644 --- a/include/linux/xarray.h +++ b/include/linux/xarray.h @@ -549,6 +549,12 @@ static inline bool xas_not_node(struct xa_node *node) return (unsigned long)node < 4096; } +/* True if the node represents RESTART or an error */ +static inline bool xas_frozen(struct xa_node *node) +{ + return (unsigned long)node & 1; +} + /* True if the node represents head-of-tree, RESTART or BOUNDS */ static inline bool xas_top(struct xa_node *node) { @@ -664,8 +670,8 @@ static inline bool xa_iter_skip(void *entry) } /* - * node->shift is always 0 for the inline iterators unless we're processing - * a multi-index entry. + * node->shift is always 0 for next_entry and next_tag unless we're processing + * a multi-index entry. It can be non-0 for next/prev, so it's not used there. */ #ifdef CONFIG_RADIX_TREE_MULTIORDER #define xa_node_shift(node) node->shift @@ -673,6 +679,67 @@ static inline bool xa_iter_skip(void *entry) #define xa_node_shift(node) 0 #endif +void *__xas_next(struct xa_state *); +void *__xas_prev(struct xa_state *); + +/** + * xas_prev() - Move iterator to previous index. + * @xas: XArray operation state. + * + * If the @xas was in an error state, it will remain in an error state + * and this function will return %NULL. If the @xas has never been walked, + * it will have the effect of calling xas_load(). Otherwise one will be + * subtracted from the index and the state will be walked to the correct + * location in the array for the next operation. + * + * If the iterator was referencing index 0, this function wraps + * around to %ULONG_MAX. + * + * Return: The entry at the new index. This may be %NULL or an internal + * entry, although it should never be a node entry. + */ +static inline void *xas_prev(struct xa_state *xas) +{ + struct xa_node *node = xas->xa_node; + + if (unlikely(xas_not_node(node) || node->shift || + xas->xa_offset == 0)) + return __xas_prev(xas); + + xas->xa_index--; + xas->xa_offset--; + return xa_entry(xas->xa, node, xas->xa_offset); +} + +/** + * xas_next() - Move state to next index. + * @xas: XArray operation state. + * + * If the @xas was in an error state, it will remain in an error state + * and this function will return %NULL. If the @xas has never been walked, + * it will have the effect of calling xas_load(). Otherwise one will be + * added to the index and the state will be walked to the correct + * location in the array for the next operation. + * + * If the iterator was referencing index %ULONG_MAX, this function wraps + * around to 0. + * + * Return: The entry at the new index. This may be %NULL or an internal + * entry, although it should never be a node entry. + */ +static inline void *xas_next(struct xa_state *xas) +{ + struct xa_node *node = xas->xa_node; + + if (unlikely(xas_not_node(node) || node->shift || + xas->xa_offset == XA_CHUNK_MASK)) + return __xas_next(xas); + + xas->xa_index++; + xas->xa_offset++; + return xa_entry(xas->xa, node, xas->xa_offset); +} + /** * xas_next_entry() - Advance iterator to next present entry. * @xas: XArray operation state. diff --git a/lib/xarray.c b/lib/xarray.c index f3875b251b41..8c6e83d10554 100644 --- a/lib/xarray.c +++ b/lib/xarray.c @@ -799,6 +799,80 @@ void xas_pause(struct xa_state *xas) } EXPORT_SYMBOL_GPL(xas_pause); +/* + * __xas_prev() - Find the previous entry in the XArray. + * @xas: XArray operation state. + * + * Helper function for xas_prev() which handles all the complex cases + * out of line. + */ +void *__xas_prev(struct xa_state *xas) +{ + void *entry; + + if (!xas_frozen(xas->xa_node)) + xas->xa_index--; + if (xas_not_node(xas->xa_node)) + return xas_load(xas); + + if (xas->xa_offset != get_offset(xas->xa_index, xas->xa_node)) + xas->xa_offset--; + + while (xas->xa_offset == 255) { + xas->xa_offset = xas->xa_node->offset - 1; + xas->xa_node = xa_parent(xas->xa, xas->xa_node); + if (!xas->xa_node) + return set_bounds(xas); + } + + for (;;) { + entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset); + if (!xa_is_node(entry)) + return entry; + + xas->xa_node = xa_to_node(entry); + xas->xa_offset = get_offset(xas->xa_index, xas->xa_node); + } +} +EXPORT_SYMBOL_GPL(__xas_prev); + +/* + * __xas_next() - Find the next entry in the XArray. + * @xas: XArray operation state. + * + * Helper function for xas_next() which handles all the complex cases + * out of line. + */ +void *__xas_next(struct xa_state *xas) +{ + void *entry; + + if (!xas_frozen(xas->xa_node)) + xas->xa_index++; + if (xas_not_node(xas->xa_node)) + return xas_load(xas); + + if (xas->xa_offset != get_offset(xas->xa_index, xas->xa_node)) + xas->xa_offset++; + + while (xas->xa_offset == XA_CHUNK_SIZE) { + xas->xa_offset = xas->xa_node->offset + 1; + xas->xa_node = xa_parent(xas->xa, xas->xa_node); + if (!xas->xa_node) + return set_bounds(xas); + } + + for (;;) { + entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset); + if (!xa_is_node(entry)) + return entry; + + xas->xa_node = xa_to_node(entry); + xas->xa_offset = get_offset(xas->xa_index, xas->xa_node); + } +} +EXPORT_SYMBOL_GPL(__xas_next); + /** * xas_find() - Find the next present entry in the XArray. * @xas: XArray operation state. diff --git a/tools/testing/radix-tree/xarray-test.c b/tools/testing/radix-tree/xarray-test.c index cc5d0b7a1edf..0946eef351e2 100644 --- a/tools/testing/radix-tree/xarray-test.c +++ b/tools/testing/radix-tree/xarray-test.c @@ -79,6 +79,104 @@ void check_xas_error(struct xarray *xa) assert(xas.xa_node == XAS_BOUNDS); } +void check_xas_pause(struct xarray *xa) +{ + XA_STATE(xas, xa, 0); + void *entry; + unsigned int seen; + + xa_store(xa, 0, xa_mk_value(0), GFP_KERNEL); + xa_set_tag(xa, 0, XA_TAG_0); + + seen = 0; + rcu_read_lock(); + xas_for_each_tag(&xas, entry, ULONG_MAX, XA_TAG_0) { + if (!seen++) { + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL); + xa_set_tag(xa, 1, XA_TAG_0); + } + } + rcu_read_unlock(); + /* We don't see an entry that was added after we started */ + assert(seen == 1); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + xas_for_each_tag(&xas, entry, ULONG_MAX, XA_TAG_0) { + if (!seen++) + xa_erase(xa, 1); + } + rcu_read_unlock(); + assert(seen == 1); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + xas_for_each(&xas, entry, ULONG_MAX) { + if (!seen++) + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL); + } + rcu_read_unlock(); + assert(seen == 1); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + xas_for_each(&xas, entry, ULONG_MAX) { + if (!seen++) + xa_erase(xa, 1); + } + rcu_read_unlock(); + assert(seen == 1); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + for (entry = xas_load(&xas); entry; entry = xas_next(&xas)) { + if (!seen++) + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL); + } + rcu_read_unlock(); + assert(seen == 2); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + for (entry = xas_load(&xas); entry; entry = xas_next(&xas)) { + if (!seen++) + xa_erase(xa, 1); + } + rcu_read_unlock(); + assert(seen == 1); + + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL); + seen = 0; + xas_set(&xas, 0); + xas_for_each(&xas, entry, ULONG_MAX) { + if (!seen++) + xas_pause(&xas); + } + assert(seen == 2); + + seen = 0; + xas_set(&xas, 0); + for (entry = xas_load(&xas); entry; entry = xas_next(&xas)) { + if (!seen++) + xas_pause(&xas); + } + assert(seen == 2); + + seen = 0; + xas_set(&xas, 0); + xa_set_tag(xa, 1, XA_TAG_0); + xas_for_each_tag(&xas, entry, ULONG_MAX, XA_TAG_0) { + if (!seen++) + xas_pause(&xas); + } + assert(seen == 2); +} + void check_xas_retry(struct xarray *xa) { XA_STATE(xas, xa, 0); @@ -216,9 +314,109 @@ void check_find(struct xarray *xa) assert(index == 16); } +void check_move_small(struct xarray *xa, unsigned long idx) +{ + XA_STATE(xas, xa, 0); + unsigned long i; + + xa_store(xa, 0, xa_mk_value(0), GFP_KERNEL); + xa_store(xa, idx, xa_mk_value(idx), GFP_KERNEL); + + for (i = 0; i < idx * 4; i++) { + void *entry = xas_next(&xas); + if (i <= idx) + assert(xas.xa_node != XAS_RESTART); + assert(xas.xa_index == i); + if (i == 0 || i == idx) + assert(entry == xa_mk_value(i)); + else + assert(entry == NULL); + } + xas_next(&xas); + assert(xas.xa_index == i); + + do { + void *entry = xas_prev(&xas); + i--; + if (i <= idx) + assert(xas.xa_node != XAS_RESTART); + assert(xas.xa_index == i); + if (i == 0 || i == idx) + assert(entry == xa_mk_value(i)); + else + assert(entry == NULL); + } while (i > 0); + + xas_set(&xas, ULONG_MAX); + assert(xas_next(&xas) == NULL); + assert(xas.xa_index == ULONG_MAX); + assert(xas_next(&xas) == xa_mk_value(0)); + assert(xas.xa_index == 0); + assert(xas_prev(&xas) == NULL); + assert(xas.xa_index == ULONG_MAX); +} + +void check_move(struct xarray *xa) +{ + XA_STATE(xas, xa, (1 << 16) - 1); + unsigned long i; + + for (i = 0; i < (1 << 16); i++) { + xa_store(xa, i, xa_mk_value(i), GFP_KERNEL); + } + + do { + void *entry = xas_prev(&xas); + i--; + assert(entry == xa_mk_value(i)); + assert(i == xas.xa_index); + } while (i != 0); + + assert(xas_prev(&xas) == NULL); + assert(xas.xa_index == ULONG_MAX); + + do { + void *entry = xas_next(&xas); + assert(entry == xa_mk_value(i)); + assert(i == xas.xa_index); + i++; + } while (i < (1 << 16)); + + for (i = (1 << 8); i < (1 << 15); i++) { + xa_erase(xa, i); + } + + i = xas.xa_index; + + do { + void *entry = xas_prev(&xas); + i--; + if ((i < (1 << 8)) || (i >= (1 << 15))) + assert(entry == xa_mk_value(i)); + else + assert(entry == NULL); + assert(i == xas.xa_index); + } while (i != 0); + + assert(xas_prev(&xas) == NULL); + assert(xas.xa_index == ULONG_MAX); + + do { + void *entry = xas_next(&xas); + if ((i < (1 << 8)) || (i >= (1 << 15))) + assert(entry == xa_mk_value(i)); + else + assert(entry == NULL); + assert(i == xas.xa_index); + i++; + } while (i < (1 << 16)); + +} + void xarray_checks(void) { DEFINE_XARRAY(array); + unsigned long i; check_xa_tag(&array); item_kill_tree(&array); @@ -229,6 +427,9 @@ void xarray_checks(void) check_xas_retry(&array); item_kill_tree(&array); + check_xas_pause(&array); + item_kill_tree(&array); + check_xa_load(&array); item_kill_tree(&array); @@ -240,6 +441,19 @@ void xarray_checks(void) check_find(&array); item_kill_tree(&array); + + for (i = 0; i < 16; i++) { + check_move_small(&array, 1UL << i); + item_kill_tree(&array); + } + + for (i = 2; i < 16; i++) { + check_move_small(&array, (1UL << i) - 1); + item_kill_tree(&array); + } + + check_move(&array); + item_kill_tree(&array); } int __weak main(void) -- 2.15.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org ([65.50.211.133]:42644 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753283AbdLFAmK (ORCPT ); Tue, 5 Dec 2017 19:42:10 -0500 From: Matthew Wilcox Subject: [PATCH v4 17/73] xarray: Add xas_next and xas_prev Date: Tue, 5 Dec 2017 16:41:03 -0800 Message-Id: <20171206004159.3755-18-willy@infradead.org> In-Reply-To: <20171206004159.3755-1-willy@infradead.org> References: <20171206004159.3755-1-willy@infradead.org> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs Cc: Matthew Wilcox , Ross Zwisler , Jens Axboe , Rehas Sachdeva , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-nilfs@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org From: Matthew Wilcox These two functions move the xas index by one position, and adjust the rest of the iterator state to match it. This is more efficient than calling xas_set() as it keeps the iterator at the leaves of the tree instead of walking the iterator from the root each time. Signed-off-by: Matthew Wilcox --- include/linux/xarray.h | 71 ++++++++++- lib/xarray.c | 74 ++++++++++++ tools/testing/radix-tree/xarray-test.c | 214 +++++++++++++++++++++++++++++++++ 3 files changed, 357 insertions(+), 2 deletions(-) diff --git a/include/linux/xarray.h b/include/linux/xarray.h index b648c1b93d9f..416708ace115 100644 --- a/include/linux/xarray.h +++ b/include/linux/xarray.h @@ -549,6 +549,12 @@ static inline bool xas_not_node(struct xa_node *node) return (unsigned long)node < 4096; } +/* True if the node represents RESTART or an error */ +static inline bool xas_frozen(struct xa_node *node) +{ + return (unsigned long)node & 1; +} + /* True if the node represents head-of-tree, RESTART or BOUNDS */ static inline bool xas_top(struct xa_node *node) { @@ -664,8 +670,8 @@ static inline bool xa_iter_skip(void *entry) } /* - * node->shift is always 0 for the inline iterators unless we're processing - * a multi-index entry. + * node->shift is always 0 for next_entry and next_tag unless we're processing + * a multi-index entry. It can be non-0 for next/prev, so it's not used there. */ #ifdef CONFIG_RADIX_TREE_MULTIORDER #define xa_node_shift(node) node->shift @@ -673,6 +679,67 @@ static inline bool xa_iter_skip(void *entry) #define xa_node_shift(node) 0 #endif +void *__xas_next(struct xa_state *); +void *__xas_prev(struct xa_state *); + +/** + * xas_prev() - Move iterator to previous index. + * @xas: XArray operation state. + * + * If the @xas was in an error state, it will remain in an error state + * and this function will return %NULL. If the @xas has never been walked, + * it will have the effect of calling xas_load(). Otherwise one will be + * subtracted from the index and the state will be walked to the correct + * location in the array for the next operation. + * + * If the iterator was referencing index 0, this function wraps + * around to %ULONG_MAX. + * + * Return: The entry at the new index. This may be %NULL or an internal + * entry, although it should never be a node entry. + */ +static inline void *xas_prev(struct xa_state *xas) +{ + struct xa_node *node = xas->xa_node; + + if (unlikely(xas_not_node(node) || node->shift || + xas->xa_offset == 0)) + return __xas_prev(xas); + + xas->xa_index--; + xas->xa_offset--; + return xa_entry(xas->xa, node, xas->xa_offset); +} + +/** + * xas_next() - Move state to next index. + * @xas: XArray operation state. + * + * If the @xas was in an error state, it will remain in an error state + * and this function will return %NULL. If the @xas has never been walked, + * it will have the effect of calling xas_load(). Otherwise one will be + * added to the index and the state will be walked to the correct + * location in the array for the next operation. + * + * If the iterator was referencing index %ULONG_MAX, this function wraps + * around to 0. + * + * Return: The entry at the new index. This may be %NULL or an internal + * entry, although it should never be a node entry. + */ +static inline void *xas_next(struct xa_state *xas) +{ + struct xa_node *node = xas->xa_node; + + if (unlikely(xas_not_node(node) || node->shift || + xas->xa_offset == XA_CHUNK_MASK)) + return __xas_next(xas); + + xas->xa_index++; + xas->xa_offset++; + return xa_entry(xas->xa, node, xas->xa_offset); +} + /** * xas_next_entry() - Advance iterator to next present entry. * @xas: XArray operation state. diff --git a/lib/xarray.c b/lib/xarray.c index f3875b251b41..8c6e83d10554 100644 --- a/lib/xarray.c +++ b/lib/xarray.c @@ -799,6 +799,80 @@ void xas_pause(struct xa_state *xas) } EXPORT_SYMBOL_GPL(xas_pause); +/* + * __xas_prev() - Find the previous entry in the XArray. + * @xas: XArray operation state. + * + * Helper function for xas_prev() which handles all the complex cases + * out of line. + */ +void *__xas_prev(struct xa_state *xas) +{ + void *entry; + + if (!xas_frozen(xas->xa_node)) + xas->xa_index--; + if (xas_not_node(xas->xa_node)) + return xas_load(xas); + + if (xas->xa_offset != get_offset(xas->xa_index, xas->xa_node)) + xas->xa_offset--; + + while (xas->xa_offset == 255) { + xas->xa_offset = xas->xa_node->offset - 1; + xas->xa_node = xa_parent(xas->xa, xas->xa_node); + if (!xas->xa_node) + return set_bounds(xas); + } + + for (;;) { + entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset); + if (!xa_is_node(entry)) + return entry; + + xas->xa_node = xa_to_node(entry); + xas->xa_offset = get_offset(xas->xa_index, xas->xa_node); + } +} +EXPORT_SYMBOL_GPL(__xas_prev); + +/* + * __xas_next() - Find the next entry in the XArray. + * @xas: XArray operation state. + * + * Helper function for xas_next() which handles all the complex cases + * out of line. + */ +void *__xas_next(struct xa_state *xas) +{ + void *entry; + + if (!xas_frozen(xas->xa_node)) + xas->xa_index++; + if (xas_not_node(xas->xa_node)) + return xas_load(xas); + + if (xas->xa_offset != get_offset(xas->xa_index, xas->xa_node)) + xas->xa_offset++; + + while (xas->xa_offset == XA_CHUNK_SIZE) { + xas->xa_offset = xas->xa_node->offset + 1; + xas->xa_node = xa_parent(xas->xa, xas->xa_node); + if (!xas->xa_node) + return set_bounds(xas); + } + + for (;;) { + entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset); + if (!xa_is_node(entry)) + return entry; + + xas->xa_node = xa_to_node(entry); + xas->xa_offset = get_offset(xas->xa_index, xas->xa_node); + } +} +EXPORT_SYMBOL_GPL(__xas_next); + /** * xas_find() - Find the next present entry in the XArray. * @xas: XArray operation state. diff --git a/tools/testing/radix-tree/xarray-test.c b/tools/testing/radix-tree/xarray-test.c index cc5d0b7a1edf..0946eef351e2 100644 --- a/tools/testing/radix-tree/xarray-test.c +++ b/tools/testing/radix-tree/xarray-test.c @@ -79,6 +79,104 @@ void check_xas_error(struct xarray *xa) assert(xas.xa_node == XAS_BOUNDS); } +void check_xas_pause(struct xarray *xa) +{ + XA_STATE(xas, xa, 0); + void *entry; + unsigned int seen; + + xa_store(xa, 0, xa_mk_value(0), GFP_KERNEL); + xa_set_tag(xa, 0, XA_TAG_0); + + seen = 0; + rcu_read_lock(); + xas_for_each_tag(&xas, entry, ULONG_MAX, XA_TAG_0) { + if (!seen++) { + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL); + xa_set_tag(xa, 1, XA_TAG_0); + } + } + rcu_read_unlock(); + /* We don't see an entry that was added after we started */ + assert(seen == 1); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + xas_for_each_tag(&xas, entry, ULONG_MAX, XA_TAG_0) { + if (!seen++) + xa_erase(xa, 1); + } + rcu_read_unlock(); + assert(seen == 1); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + xas_for_each(&xas, entry, ULONG_MAX) { + if (!seen++) + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL); + } + rcu_read_unlock(); + assert(seen == 1); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + xas_for_each(&xas, entry, ULONG_MAX) { + if (!seen++) + xa_erase(xa, 1); + } + rcu_read_unlock(); + assert(seen == 1); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + for (entry = xas_load(&xas); entry; entry = xas_next(&xas)) { + if (!seen++) + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL); + } + rcu_read_unlock(); + assert(seen == 2); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + for (entry = xas_load(&xas); entry; entry = xas_next(&xas)) { + if (!seen++) + xa_erase(xa, 1); + } + rcu_read_unlock(); + assert(seen == 1); + + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL); + seen = 0; + xas_set(&xas, 0); + xas_for_each(&xas, entry, ULONG_MAX) { + if (!seen++) + xas_pause(&xas); + } + assert(seen == 2); + + seen = 0; + xas_set(&xas, 0); + for (entry = xas_load(&xas); entry; entry = xas_next(&xas)) { + if (!seen++) + xas_pause(&xas); + } + assert(seen == 2); + + seen = 0; + xas_set(&xas, 0); + xa_set_tag(xa, 1, XA_TAG_0); + xas_for_each_tag(&xas, entry, ULONG_MAX, XA_TAG_0) { + if (!seen++) + xas_pause(&xas); + } + assert(seen == 2); +} + void check_xas_retry(struct xarray *xa) { XA_STATE(xas, xa, 0); @@ -216,9 +314,109 @@ void check_find(struct xarray *xa) assert(index == 16); } +void check_move_small(struct xarray *xa, unsigned long idx) +{ + XA_STATE(xas, xa, 0); + unsigned long i; + + xa_store(xa, 0, xa_mk_value(0), GFP_KERNEL); + xa_store(xa, idx, xa_mk_value(idx), GFP_KERNEL); + + for (i = 0; i < idx * 4; i++) { + void *entry = xas_next(&xas); + if (i <= idx) + assert(xas.xa_node != XAS_RESTART); + assert(xas.xa_index == i); + if (i == 0 || i == idx) + assert(entry == xa_mk_value(i)); + else + assert(entry == NULL); + } + xas_next(&xas); + assert(xas.xa_index == i); + + do { + void *entry = xas_prev(&xas); + i--; + if (i <= idx) + assert(xas.xa_node != XAS_RESTART); + assert(xas.xa_index == i); + if (i == 0 || i == idx) + assert(entry == xa_mk_value(i)); + else + assert(entry == NULL); + } while (i > 0); + + xas_set(&xas, ULONG_MAX); + assert(xas_next(&xas) == NULL); + assert(xas.xa_index == ULONG_MAX); + assert(xas_next(&xas) == xa_mk_value(0)); + assert(xas.xa_index == 0); + assert(xas_prev(&xas) == NULL); + assert(xas.xa_index == ULONG_MAX); +} + +void check_move(struct xarray *xa) +{ + XA_STATE(xas, xa, (1 << 16) - 1); + unsigned long i; + + for (i = 0; i < (1 << 16); i++) { + xa_store(xa, i, xa_mk_value(i), GFP_KERNEL); + } + + do { + void *entry = xas_prev(&xas); + i--; + assert(entry == xa_mk_value(i)); + assert(i == xas.xa_index); + } while (i != 0); + + assert(xas_prev(&xas) == NULL); + assert(xas.xa_index == ULONG_MAX); + + do { + void *entry = xas_next(&xas); + assert(entry == xa_mk_value(i)); + assert(i == xas.xa_index); + i++; + } while (i < (1 << 16)); + + for (i = (1 << 8); i < (1 << 15); i++) { + xa_erase(xa, i); + } + + i = xas.xa_index; + + do { + void *entry = xas_prev(&xas); + i--; + if ((i < (1 << 8)) || (i >= (1 << 15))) + assert(entry == xa_mk_value(i)); + else + assert(entry == NULL); + assert(i == xas.xa_index); + } while (i != 0); + + assert(xas_prev(&xas) == NULL); + assert(xas.xa_index == ULONG_MAX); + + do { + void *entry = xas_next(&xas); + if ((i < (1 << 8)) || (i >= (1 << 15))) + assert(entry == xa_mk_value(i)); + else + assert(entry == NULL); + assert(i == xas.xa_index); + i++; + } while (i < (1 << 16)); + +} + void xarray_checks(void) { DEFINE_XARRAY(array); + unsigned long i; check_xa_tag(&array); item_kill_tree(&array); @@ -229,6 +427,9 @@ void xarray_checks(void) check_xas_retry(&array); item_kill_tree(&array); + check_xas_pause(&array); + item_kill_tree(&array); + check_xa_load(&array); item_kill_tree(&array); @@ -240,6 +441,19 @@ void xarray_checks(void) check_find(&array); item_kill_tree(&array); + + for (i = 0; i < 16; i++) { + check_move_small(&array, 1UL << i); + item_kill_tree(&array); + } + + for (i = 2; i < 16; i++) { + check_move_small(&array, (1UL << i) - 1); + item_kill_tree(&array); + } + + check_move(&array); + item_kill_tree(&array); } int __weak main(void) -- 2.15.0 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f200.google.com (mail-pf0-f200.google.com [209.85.192.200]) by kanga.kvack.org (Postfix) with ESMTP id B12BA6B02C9 for ; Tue, 5 Dec 2017 19:43:50 -0500 (EST) Received: by mail-pf0-f200.google.com with SMTP id h18so1637498pfi.2 for ; Tue, 05 Dec 2017 16:43:50 -0800 (PST) Received: from bombadil.infradead.org (bombadil.infradead.org. [65.50.211.133]) by mx.google.com with ESMTPS id v204si867325pgb.639.2017.12.05.16.42.09 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 05 Dec 2017 16:42:09 -0800 (PST) From: Matthew Wilcox Subject: [PATCH v4 17/73] xarray: Add xas_next and xas_prev Date: Tue, 5 Dec 2017 16:41:03 -0800 Message-Id: <20171206004159.3755-18-willy@infradead.org> In-Reply-To: <20171206004159.3755-1-willy@infradead.org> References: <20171206004159.3755-1-willy@infradead.org> Sender: owner-linux-mm@kvack.org List-ID: Cc: Matthew Wilcox , Ross Zwisler , Jens Axboe , Rehas Sachdeva , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-nilfs@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org From: Matthew Wilcox These two functions move the xas index by one position, and adjust the rest of the iterator state to match it. This is more efficient than calling xas_set() as it keeps the iterator at the leaves of the tree instead of walking the iterator from the root each time. Signed-off-by: Matthew Wilcox --- include/linux/xarray.h | 71 ++++++++++- lib/xarray.c | 74 ++++++++++++ tools/testing/radix-tree/xarray-test.c | 214 +++++++++++++++++++++++++++++++++ 3 files changed, 357 insertions(+), 2 deletions(-) diff --git a/include/linux/xarray.h b/include/linux/xarray.h index b648c1b93d9f..416708ace115 100644 --- a/include/linux/xarray.h +++ b/include/linux/xarray.h @@ -549,6 +549,12 @@ static inline bool xas_not_node(struct xa_node *node) return (unsigned long)node < 4096; } +/* True if the node represents RESTART or an error */ +static inline bool xas_frozen(struct xa_node *node) +{ + return (unsigned long)node & 1; +} + /* True if the node represents head-of-tree, RESTART or BOUNDS */ static inline bool xas_top(struct xa_node *node) { @@ -664,8 +670,8 @@ static inline bool xa_iter_skip(void *entry) } /* - * node->shift is always 0 for the inline iterators unless we're processing - * a multi-index entry. + * node->shift is always 0 for next_entry and next_tag unless we're processing + * a multi-index entry. It can be non-0 for next/prev, so it's not used there. */ #ifdef CONFIG_RADIX_TREE_MULTIORDER #define xa_node_shift(node) node->shift @@ -673,6 +679,67 @@ static inline bool xa_iter_skip(void *entry) #define xa_node_shift(node) 0 #endif +void *__xas_next(struct xa_state *); +void *__xas_prev(struct xa_state *); + +/** + * xas_prev() - Move iterator to previous index. + * @xas: XArray operation state. + * + * If the @xas was in an error state, it will remain in an error state + * and this function will return %NULL. If the @xas has never been walked, + * it will have the effect of calling xas_load(). Otherwise one will be + * subtracted from the index and the state will be walked to the correct + * location in the array for the next operation. + * + * If the iterator was referencing index 0, this function wraps + * around to %ULONG_MAX. + * + * Return: The entry at the new index. This may be %NULL or an internal + * entry, although it should never be a node entry. + */ +static inline void *xas_prev(struct xa_state *xas) +{ + struct xa_node *node = xas->xa_node; + + if (unlikely(xas_not_node(node) || node->shift || + xas->xa_offset == 0)) + return __xas_prev(xas); + + xas->xa_index--; + xas->xa_offset--; + return xa_entry(xas->xa, node, xas->xa_offset); +} + +/** + * xas_next() - Move state to next index. + * @xas: XArray operation state. + * + * If the @xas was in an error state, it will remain in an error state + * and this function will return %NULL. If the @xas has never been walked, + * it will have the effect of calling xas_load(). Otherwise one will be + * added to the index and the state will be walked to the correct + * location in the array for the next operation. + * + * If the iterator was referencing index %ULONG_MAX, this function wraps + * around to 0. + * + * Return: The entry at the new index. This may be %NULL or an internal + * entry, although it should never be a node entry. + */ +static inline void *xas_next(struct xa_state *xas) +{ + struct xa_node *node = xas->xa_node; + + if (unlikely(xas_not_node(node) || node->shift || + xas->xa_offset == XA_CHUNK_MASK)) + return __xas_next(xas); + + xas->xa_index++; + xas->xa_offset++; + return xa_entry(xas->xa, node, xas->xa_offset); +} + /** * xas_next_entry() - Advance iterator to next present entry. * @xas: XArray operation state. diff --git a/lib/xarray.c b/lib/xarray.c index f3875b251b41..8c6e83d10554 100644 --- a/lib/xarray.c +++ b/lib/xarray.c @@ -799,6 +799,80 @@ void xas_pause(struct xa_state *xas) } EXPORT_SYMBOL_GPL(xas_pause); +/* + * __xas_prev() - Find the previous entry in the XArray. + * @xas: XArray operation state. + * + * Helper function for xas_prev() which handles all the complex cases + * out of line. + */ +void *__xas_prev(struct xa_state *xas) +{ + void *entry; + + if (!xas_frozen(xas->xa_node)) + xas->xa_index--; + if (xas_not_node(xas->xa_node)) + return xas_load(xas); + + if (xas->xa_offset != get_offset(xas->xa_index, xas->xa_node)) + xas->xa_offset--; + + while (xas->xa_offset == 255) { + xas->xa_offset = xas->xa_node->offset - 1; + xas->xa_node = xa_parent(xas->xa, xas->xa_node); + if (!xas->xa_node) + return set_bounds(xas); + } + + for (;;) { + entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset); + if (!xa_is_node(entry)) + return entry; + + xas->xa_node = xa_to_node(entry); + xas->xa_offset = get_offset(xas->xa_index, xas->xa_node); + } +} +EXPORT_SYMBOL_GPL(__xas_prev); + +/* + * __xas_next() - Find the next entry in the XArray. + * @xas: XArray operation state. + * + * Helper function for xas_next() which handles all the complex cases + * out of line. + */ +void *__xas_next(struct xa_state *xas) +{ + void *entry; + + if (!xas_frozen(xas->xa_node)) + xas->xa_index++; + if (xas_not_node(xas->xa_node)) + return xas_load(xas); + + if (xas->xa_offset != get_offset(xas->xa_index, xas->xa_node)) + xas->xa_offset++; + + while (xas->xa_offset == XA_CHUNK_SIZE) { + xas->xa_offset = xas->xa_node->offset + 1; + xas->xa_node = xa_parent(xas->xa, xas->xa_node); + if (!xas->xa_node) + return set_bounds(xas); + } + + for (;;) { + entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset); + if (!xa_is_node(entry)) + return entry; + + xas->xa_node = xa_to_node(entry); + xas->xa_offset = get_offset(xas->xa_index, xas->xa_node); + } +} +EXPORT_SYMBOL_GPL(__xas_next); + /** * xas_find() - Find the next present entry in the XArray. * @xas: XArray operation state. diff --git a/tools/testing/radix-tree/xarray-test.c b/tools/testing/radix-tree/xarray-test.c index cc5d0b7a1edf..0946eef351e2 100644 --- a/tools/testing/radix-tree/xarray-test.c +++ b/tools/testing/radix-tree/xarray-test.c @@ -79,6 +79,104 @@ void check_xas_error(struct xarray *xa) assert(xas.xa_node == XAS_BOUNDS); } +void check_xas_pause(struct xarray *xa) +{ + XA_STATE(xas, xa, 0); + void *entry; + unsigned int seen; + + xa_store(xa, 0, xa_mk_value(0), GFP_KERNEL); + xa_set_tag(xa, 0, XA_TAG_0); + + seen = 0; + rcu_read_lock(); + xas_for_each_tag(&xas, entry, ULONG_MAX, XA_TAG_0) { + if (!seen++) { + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL); + xa_set_tag(xa, 1, XA_TAG_0); + } + } + rcu_read_unlock(); + /* We don't see an entry that was added after we started */ + assert(seen == 1); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + xas_for_each_tag(&xas, entry, ULONG_MAX, XA_TAG_0) { + if (!seen++) + xa_erase(xa, 1); + } + rcu_read_unlock(); + assert(seen == 1); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + xas_for_each(&xas, entry, ULONG_MAX) { + if (!seen++) + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL); + } + rcu_read_unlock(); + assert(seen == 1); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + xas_for_each(&xas, entry, ULONG_MAX) { + if (!seen++) + xa_erase(xa, 1); + } + rcu_read_unlock(); + assert(seen == 1); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + for (entry = xas_load(&xas); entry; entry = xas_next(&xas)) { + if (!seen++) + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL); + } + rcu_read_unlock(); + assert(seen == 2); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + for (entry = xas_load(&xas); entry; entry = xas_next(&xas)) { + if (!seen++) + xa_erase(xa, 1); + } + rcu_read_unlock(); + assert(seen == 1); + + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL); + seen = 0; + xas_set(&xas, 0); + xas_for_each(&xas, entry, ULONG_MAX) { + if (!seen++) + xas_pause(&xas); + } + assert(seen == 2); + + seen = 0; + xas_set(&xas, 0); + for (entry = xas_load(&xas); entry; entry = xas_next(&xas)) { + if (!seen++) + xas_pause(&xas); + } + assert(seen == 2); + + seen = 0; + xas_set(&xas, 0); + xa_set_tag(xa, 1, XA_TAG_0); + xas_for_each_tag(&xas, entry, ULONG_MAX, XA_TAG_0) { + if (!seen++) + xas_pause(&xas); + } + assert(seen == 2); +} + void check_xas_retry(struct xarray *xa) { XA_STATE(xas, xa, 0); @@ -216,9 +314,109 @@ void check_find(struct xarray *xa) assert(index == 16); } +void check_move_small(struct xarray *xa, unsigned long idx) +{ + XA_STATE(xas, xa, 0); + unsigned long i; + + xa_store(xa, 0, xa_mk_value(0), GFP_KERNEL); + xa_store(xa, idx, xa_mk_value(idx), GFP_KERNEL); + + for (i = 0; i < idx * 4; i++) { + void *entry = xas_next(&xas); + if (i <= idx) + assert(xas.xa_node != XAS_RESTART); + assert(xas.xa_index == i); + if (i == 0 || i == idx) + assert(entry == xa_mk_value(i)); + else + assert(entry == NULL); + } + xas_next(&xas); + assert(xas.xa_index == i); + + do { + void *entry = xas_prev(&xas); + i--; + if (i <= idx) + assert(xas.xa_node != XAS_RESTART); + assert(xas.xa_index == i); + if (i == 0 || i == idx) + assert(entry == xa_mk_value(i)); + else + assert(entry == NULL); + } while (i > 0); + + xas_set(&xas, ULONG_MAX); + assert(xas_next(&xas) == NULL); + assert(xas.xa_index == ULONG_MAX); + assert(xas_next(&xas) == xa_mk_value(0)); + assert(xas.xa_index == 0); + assert(xas_prev(&xas) == NULL); + assert(xas.xa_index == ULONG_MAX); +} + +void check_move(struct xarray *xa) +{ + XA_STATE(xas, xa, (1 << 16) - 1); + unsigned long i; + + for (i = 0; i < (1 << 16); i++) { + xa_store(xa, i, xa_mk_value(i), GFP_KERNEL); + } + + do { + void *entry = xas_prev(&xas); + i--; + assert(entry == xa_mk_value(i)); + assert(i == xas.xa_index); + } while (i != 0); + + assert(xas_prev(&xas) == NULL); + assert(xas.xa_index == ULONG_MAX); + + do { + void *entry = xas_next(&xas); + assert(entry == xa_mk_value(i)); + assert(i == xas.xa_index); + i++; + } while (i < (1 << 16)); + + for (i = (1 << 8); i < (1 << 15); i++) { + xa_erase(xa, i); + } + + i = xas.xa_index; + + do { + void *entry = xas_prev(&xas); + i--; + if ((i < (1 << 8)) || (i >= (1 << 15))) + assert(entry == xa_mk_value(i)); + else + assert(entry == NULL); + assert(i == xas.xa_index); + } while (i != 0); + + assert(xas_prev(&xas) == NULL); + assert(xas.xa_index == ULONG_MAX); + + do { + void *entry = xas_next(&xas); + if ((i < (1 << 8)) || (i >= (1 << 15))) + assert(entry == xa_mk_value(i)); + else + assert(entry == NULL); + assert(i == xas.xa_index); + i++; + } while (i < (1 << 16)); + +} + void xarray_checks(void) { DEFINE_XARRAY(array); + unsigned long i; check_xa_tag(&array); item_kill_tree(&array); @@ -229,6 +427,9 @@ void xarray_checks(void) check_xas_retry(&array); item_kill_tree(&array); + check_xas_pause(&array); + item_kill_tree(&array); + check_xa_load(&array); item_kill_tree(&array); @@ -240,6 +441,19 @@ void xarray_checks(void) check_find(&array); item_kill_tree(&array); + + for (i = 0; i < 16; i++) { + check_move_small(&array, 1UL << i); + item_kill_tree(&array); + } + + for (i = 2; i < 16; i++) { + check_move_small(&array, (1UL << i) - 1); + item_kill_tree(&array); + } + + check_move(&array); + item_kill_tree(&array); } int __weak main(void) -- 2.15.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: [PATCH v4 17/73] xarray: Add xas_next and xas_prev Date: Tue, 5 Dec 2017 16:41:03 -0800 Message-ID: <20171206004159.3755-18-willy@infradead.org> References: <20171206004159.3755-1-willy@infradead.org> Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=References:In-Reply-To:Message-Id: Date:Subject:Cc:To:From:Sender:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=SmmlwI64U8N2ap4/Ob+Did1vwVnG+jPjQ3BfBjvS724=; b=rY+Y5LgRRYMQBvK49VjQco8dl NyiMkIOAIM+VpqvTI3cAD4RpIoFain9gJLVJUuO8vGTq6y/yaPXMlFfi9gimWJchSBh1Qq5t8liFH j/dyfTvquEmFOaF+SNZcjh46RYOgFVstseGvzl1dZYtxpS3TA68fC8lhw2znKTMQOaGOpdpW/0LyF H57LwloHCY96iLf6471DbwJPoz074e5hLOM38YIc37WwfS7hAJq6UvyocpntgDjpy3PPHanN+BwYL O5A+sjxJb/hlo2XnT5va3BTKNx40ACP21QbDB5ziX2DnlSVtYTQDe/JNqoUqj0QPnlr7hJFhMiu7X In-Reply-To: <20171206004159.3755-1-willy@infradead.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Cc: Matthew Wilcox , Ross Zwisler , Jens Axboe , Rehas Sachdeva , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-nilfs@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org From: Matthew Wilcox These two functions move the xas index by one position, and adjust the rest of the iterator state to match it. This is more efficient than calling xas_set() as it keeps the iterator at the leaves of the tree instead of walking the iterator from the root each time. Signed-off-by: Matthew Wilcox --- include/linux/xarray.h | 71 ++++++++++- lib/xarray.c | 74 ++++++++++++ tools/testing/radix-tree/xarray-test.c | 214 +++++++++++++++++++++++++++++++++ 3 files changed, 357 insertions(+), 2 deletions(-) diff --git a/include/linux/xarray.h b/include/linux/xarray.h index b648c1b93d9f..416708ace115 100644 --- a/include/linux/xarray.h +++ b/include/linux/xarray.h @@ -549,6 +549,12 @@ static inline bool xas_not_node(struct xa_node *node) return (unsigned long)node < 4096; } +/* True if the node represents RESTART or an error */ +static inline bool xas_frozen(struct xa_node *node) +{ + return (unsigned long)node & 1; +} + /* True if the node represents head-of-tree, RESTART or BOUNDS */ static inline bool xas_top(struct xa_node *node) { @@ -664,8 +670,8 @@ static inline bool xa_iter_skip(void *entry) } /* - * node->shift is always 0 for the inline iterators unless we're processing - * a multi-index entry. + * node->shift is always 0 for next_entry and next_tag unless we're processing + * a multi-index entry. It can be non-0 for next/prev, so it's not used there. */ #ifdef CONFIG_RADIX_TREE_MULTIORDER #define xa_node_shift(node) node->shift @@ -673,6 +679,67 @@ static inline bool xa_iter_skip(void *entry) #define xa_node_shift(node) 0 #endif +void *__xas_next(struct xa_state *); +void *__xas_prev(struct xa_state *); + +/** + * xas_prev() - Move iterator to previous index. + * @xas: XArray operation state. + * + * If the @xas was in an error state, it will remain in an error state + * and this function will return %NULL. If the @xas has never been walked, + * it will have the effect of calling xas_load(). Otherwise one will be + * subtracted from the index and the state will be walked to the correct + * location in the array for the next operation. + * + * If the iterator was referencing index 0, this function wraps + * around to %ULONG_MAX. + * + * Return: The entry at the new index. This may be %NULL or an internal + * entry, although it should never be a node entry. + */ +static inline void *xas_prev(struct xa_state *xas) +{ + struct xa_node *node = xas->xa_node; + + if (unlikely(xas_not_node(node) || node->shift || + xas->xa_offset == 0)) + return __xas_prev(xas); + + xas->xa_index--; + xas->xa_offset--; + return xa_entry(xas->xa, node, xas->xa_offset); +} + +/** + * xas_next() - Move state to next index. + * @xas: XArray operation state. + * + * If the @xas was in an error state, it will remain in an error state + * and this function will return %NULL. If the @xas has never been walked, + * it will have the effect of calling xas_load(). Otherwise one will be + * added to the index and the state will be walked to the correct + * location in the array for the next operation. + * + * If the iterator was referencing index %ULONG_MAX, this function wraps + * around to 0. + * + * Return: The entry at the new index. This may be %NULL or an internal + * entry, although it should never be a node entry. + */ +static inline void *xas_next(struct xa_state *xas) +{ + struct xa_node *node = xas->xa_node; + + if (unlikely(xas_not_node(node) || node->shift || + xas->xa_offset == XA_CHUNK_MASK)) + return __xas_next(xas); + + xas->xa_index++; + xas->xa_offset++; + return xa_entry(xas->xa, node, xas->xa_offset); +} + /** * xas_next_entry() - Advance iterator to next present entry. * @xas: XArray operation state. diff --git a/lib/xarray.c b/lib/xarray.c index f3875b251b41..8c6e83d10554 100644 --- a/lib/xarray.c +++ b/lib/xarray.c @@ -799,6 +799,80 @@ void xas_pause(struct xa_state *xas) } EXPORT_SYMBOL_GPL(xas_pause); +/* + * __xas_prev() - Find the previous entry in the XArray. + * @xas: XArray operation state. + * + * Helper function for xas_prev() which handles all the complex cases + * out of line. + */ +void *__xas_prev(struct xa_state *xas) +{ + void *entry; + + if (!xas_frozen(xas->xa_node)) + xas->xa_index--; + if (xas_not_node(xas->xa_node)) + return xas_load(xas); + + if (xas->xa_offset != get_offset(xas->xa_index, xas->xa_node)) + xas->xa_offset--; + + while (xas->xa_offset == 255) { + xas->xa_offset = xas->xa_node->offset - 1; + xas->xa_node = xa_parent(xas->xa, xas->xa_node); + if (!xas->xa_node) + return set_bounds(xas); + } + + for (;;) { + entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset); + if (!xa_is_node(entry)) + return entry; + + xas->xa_node = xa_to_node(entry); + xas->xa_offset = get_offset(xas->xa_index, xas->xa_node); + } +} +EXPORT_SYMBOL_GPL(__xas_prev); + +/* + * __xas_next() - Find the next entry in the XArray. + * @xas: XArray operation state. + * + * Helper function for xas_next() which handles all the complex cases + * out of line. + */ +void *__xas_next(struct xa_state *xas) +{ + void *entry; + + if (!xas_frozen(xas->xa_node)) + xas->xa_index++; + if (xas_not_node(xas->xa_node)) + return xas_load(xas); + + if (xas->xa_offset != get_offset(xas->xa_index, xas->xa_node)) + xas->xa_offset++; + + while (xas->xa_offset == XA_CHUNK_SIZE) { + xas->xa_offset = xas->xa_node->offset + 1; + xas->xa_node = xa_parent(xas->xa, xas->xa_node); + if (!xas->xa_node) + return set_bounds(xas); + } + + for (;;) { + entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset); + if (!xa_is_node(entry)) + return entry; + + xas->xa_node = xa_to_node(entry); + xas->xa_offset = get_offset(xas->xa_index, xas->xa_node); + } +} +EXPORT_SYMBOL_GPL(__xas_next); + /** * xas_find() - Find the next present entry in the XArray. * @xas: XArray operation state. diff --git a/tools/testing/radix-tree/xarray-test.c b/tools/testing/radix-tree/xarray-test.c index cc5d0b7a1edf..0946eef351e2 100644 --- a/tools/testing/radix-tree/xarray-test.c +++ b/tools/testing/radix-tree/xarray-test.c @@ -79,6 +79,104 @@ void check_xas_error(struct xarray *xa) assert(xas.xa_node == XAS_BOUNDS); } +void check_xas_pause(struct xarray *xa) +{ + XA_STATE(xas, xa, 0); + void *entry; + unsigned int seen; + + xa_store(xa, 0, xa_mk_value(0), GFP_KERNEL); + xa_set_tag(xa, 0, XA_TAG_0); + + seen = 0; + rcu_read_lock(); + xas_for_each_tag(&xas, entry, ULONG_MAX, XA_TAG_0) { + if (!seen++) { + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL); + xa_set_tag(xa, 1, XA_TAG_0); + } + } + rcu_read_unlock(); + /* We don't see an entry that was added after we started */ + assert(seen == 1); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + xas_for_each_tag(&xas, entry, ULONG_MAX, XA_TAG_0) { + if (!seen++) + xa_erase(xa, 1); + } + rcu_read_unlock(); + assert(seen == 1); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + xas_for_each(&xas, entry, ULONG_MAX) { + if (!seen++) + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL); + } + rcu_read_unlock(); + assert(seen == 1); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + xas_for_each(&xas, entry, ULONG_MAX) { + if (!seen++) + xa_erase(xa, 1); + } + rcu_read_unlock(); + assert(seen == 1); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + for (entry = xas_load(&xas); entry; entry = xas_next(&xas)) { + if (!seen++) + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL); + } + rcu_read_unlock(); + assert(seen == 2); + + seen = 0; + xas_set(&xas, 0); + rcu_read_lock(); + for (entry = xas_load(&xas); entry; entry = xas_next(&xas)) { + if (!seen++) + xa_erase(xa, 1); + } + rcu_read_unlock(); + assert(seen == 1); + + xa_store(xa, 1, xa_mk_value(1), GFP_KERNEL); + seen = 0; + xas_set(&xas, 0); + xas_for_each(&xas, entry, ULONG_MAX) { + if (!seen++) + xas_pause(&xas); + } + assert(seen == 2); + + seen = 0; + xas_set(&xas, 0); + for (entry = xas_load(&xas); entry; entry = xas_next(&xas)) { + if (!seen++) + xas_pause(&xas); + } + assert(seen == 2); + + seen = 0; + xas_set(&xas, 0); + xa_set_tag(xa, 1, XA_TAG_0); + xas_for_each_tag(&xas, entry, ULONG_MAX, XA_TAG_0) { + if (!seen++) + xas_pause(&xas); + } + assert(seen == 2); +} + void check_xas_retry(struct xarray *xa) { XA_STATE(xas, xa, 0); @@ -216,9 +314,109 @@ void check_find(struct xarray *xa) assert(index == 16); } +void check_move_small(struct xarray *xa, unsigned long idx) +{ + XA_STATE(xas, xa, 0); + unsigned long i; + + xa_store(xa, 0, xa_mk_value(0), GFP_KERNEL); + xa_store(xa, idx, xa_mk_value(idx), GFP_KERNEL); + + for (i = 0; i < idx * 4; i++) { + void *entry = xas_next(&xas); + if (i <= idx) + assert(xas.xa_node != XAS_RESTART); + assert(xas.xa_index == i); + if (i == 0 || i == idx) + assert(entry == xa_mk_value(i)); + else + assert(entry == NULL); + } + xas_next(&xas); + assert(xas.xa_index == i); + + do { + void *entry = xas_prev(&xas); + i--; + if (i <= idx) + assert(xas.xa_node != XAS_RESTART); + assert(xas.xa_index == i); + if (i == 0 || i == idx) + assert(entry == xa_mk_value(i)); + else + assert(entry == NULL); + } while (i > 0); + + xas_set(&xas, ULONG_MAX); + assert(xas_next(&xas) == NULL); + assert(xas.xa_index == ULONG_MAX); + assert(xas_next(&xas) == xa_mk_value(0)); + assert(xas.xa_index == 0); + assert(xas_prev(&xas) == NULL); + assert(xas.xa_index == ULONG_MAX); +} + +void check_move(struct xarray *xa) +{ + XA_STATE(xas, xa, (1 << 16) - 1); + unsigned long i; + + for (i = 0; i < (1 << 16); i++) { + xa_store(xa, i, xa_mk_value(i), GFP_KERNEL); + } + + do { + void *entry = xas_prev(&xas); + i--; + assert(entry == xa_mk_value(i)); + assert(i == xas.xa_index); + } while (i != 0); + + assert(xas_prev(&xas) == NULL); + assert(xas.xa_index == ULONG_MAX); + + do { + void *entry = xas_next(&xas); + assert(entry == xa_mk_value(i)); + assert(i == xas.xa_index); + i++; + } while (i < (1 << 16)); + + for (i = (1 << 8); i < (1 << 15); i++) { + xa_erase(xa, i); + } + + i = xas.xa_index; + + do { + void *entry = xas_prev(&xas); + i--; + if ((i < (1 << 8)) || (i >= (1 << 15))) + assert(entry == xa_mk_value(i)); + else + assert(entry == NULL); + assert(i == xas.xa_index); + } while (i != 0); + + assert(xas_prev(&xas) == NULL); + assert(xas.xa_index == ULONG_MAX); + + do { + void *entry = xas_next(&xas); + if ((i < (1 << 8)) || (i >= (1 << 15))) + assert(entry == xa_mk_value(i)); + else + assert(entry == NULL); + assert(i == xas.xa_index); + i++; + } while (i < (1 << 16)); + +} + void xarray_checks(void) { DEFINE_XARRAY(array); + unsigned long i; check_xa_tag(&array); item_kill_tree(&array); @@ -229,6 +427,9 @@ void xarray_checks(void) check_xas_retry(&array); item_kill_tree(&array); + check_xas_pause(&array); + item_kill_tree(&array); + check_xa_load(&array); item_kill_tree(&array); @@ -240,6 +441,19 @@ void xarray_checks(void) check_find(&array); item_kill_tree(&array); + + for (i = 0; i < 16; i++) { + check_move_small(&array, 1UL << i); + item_kill_tree(&array); + } + + for (i = 2; i < 16; i++) { + check_move_small(&array, (1UL << i) - 1); + item_kill_tree(&array); + } + + check_move(&array); + item_kill_tree(&array); } int __weak main(void) -- 2.15.0