[v18,05/10] xbitmap: add more operations

Message ID	1511963726-34070-6-git-send-email-wei.w.wang@intel.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org> From: Wei Wang <wei.w.wang@intel.com> To: virtio-dev@lists.oasis-open.org, linux-kernel@vger.kernel.org, qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, linux-mm@kvack.org, mst@redhat.com, mhocko@kernel.org, akpm@linux-foundation.org, mawilcox@microsoft.com Date: Wed, 29 Nov 2017 21:55:21 +0800 Message-Id: <1511963726-34070-6-git-send-email-wei.w.wang@intel.com> In-Reply-To: <1511963726-34070-1-git-send-email-wei.w.wang@intel.com> References: <1511963726-34070-1-git-send-email-wei.w.wang@intel.com> Subject: [Qemu-devel] [PATCH v18 05/10] xbitmap: add more operations Precedence: list Cc: aarcange@redhat.com, yang.zhang.wz@gmail.com, david@redhat.com, penguin-kernel@I-love.SAKURA.ne.jp, liliang.opensource@gmail.com, willy@infradead.org, amit.shah@redhat.com, wei.w.wang@intel.com, quan.xu@aliyun.com, cornelia.huck@de.ibm.com, pbonzini@redhat.com, nilal@redhat.com, mgorman@techsingularity.net Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" <qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org>

diff --git a/include/linux/xbitmap.h b/include/linux/xbitmap.h index b4d8375..eddf0d5e 100644 --- a/include/linux/xbitmap.h +++ b/include/linux/xbitmap.h @@ -33,8 +33,14 @@ static inline void xb_init(struct xb *xb) } int xb_set_bit(struct xb *xb, unsigned long bit); +int xb_preload_and_set_bit(struct xb *xb, unsigned long bit, gfp_t gfp); bool xb_test_bit(const struct xb *xb, unsigned long bit); -int xb_clear_bit(struct xb *xb, unsigned long bit); +void xb_clear_bit(struct xb *xb, unsigned long bit); +unsigned long xb_find_next_set_bit(struct xb *xb, unsigned long start, + unsigned long end); +unsigned long xb_find_next_zero_bit(struct xb *xb, unsigned long start, + unsigned long end); +void xb_clear_bit_range(struct xb *xb, unsigned long start, unsigned long end); static inline bool xb_empty(const struct xb *xb) { diff --git a/lib/xbitmap.c b/lib/xbitmap.c index 182aa29..816dd3e 100644 --- a/lib/xbitmap.c +++ b/lib/xbitmap.c @@ -3,6 +3,13 @@ #include <linux/bitmap.h> #include <linux/slab.h> +/* + * Developer notes: locks are required to gurantee there is no concurrent + * calls of xb_set_bit, xb_clear_bit, xb_clear_bit_range, xb_test_bit, + * xb_find_next_set_bit, or xb_find_next_clear_bit to operate on the same + * ida bitamp. + */ + /** * xb_set_bit - set a bit in the xbitmap * @xb: the xbitmap tree used to record the bit @@ -70,6 +77,28 @@ int xb_set_bit(struct xb *xb, unsigned long bit) EXPORT_SYMBOL(xb_set_bit); /** + * xb_preload_and_set_bit - preload the memory and set a bit in the xbitmap + * @xb: the xbitmap tree used to record the bit + * @bit: index of the bit to set + * + * A wrapper of the xb_preload() and xb_set_bit(). + * Returns: 0 on success; -EAGAIN or -ENOMEM on error. + */ +int xb_preload_and_set_bit(struct xb *xb, unsigned long bit, gfp_t gfp) +{ + int ret = 0; + + if (!xb_preload(gfp)) + return -ENOMEM; + + ret = xb_set_bit(xb, bit); + xb_preload_end(); + + return ret; +} +EXPORT_SYMBOL(xb_preload_and_set_bit); + +/** * xb_clear_bit - clear a bit in the xbitmap * @xb: the xbitmap tree used to record the bit * @bit: index of the bit to clear @@ -115,6 +144,56 @@ void xb_clear_bit(struct xb *xb, unsigned long bit) EXPORT_SYMBOL(xb_clear_bit); /** + * xb_clear_bit - clear a range of bits in the xbitmap + * @start: the start of the bit range, inclusive + * @end: the end of the bit range, inclusive + * + * This function is used to clear a bit in the xbitmap. If all the bits of the + * bitmap are 0, the bitmap will be freed. + */ +void xb_clear_bit_range(struct xb *xb, unsigned long start, unsigned long end) +{ + struct radix_tree_root *root = &xb->xbrt; + struct radix_tree_node *node; + void **slot; + struct ida_bitmap *bitmap; + unsigned int nbits; + + for (; start < end; start = (start | (IDA_BITMAP_BITS - 1)) + 1) { + unsigned long index = start / IDA_BITMAP_BITS; + unsigned long bit = start % IDA_BITMAP_BITS; + + bitmap = __radix_tree_lookup(root, index, &node, &slot); + if (radix_tree_exception(bitmap)) { + unsigned long ebit = bit + 2; + unsigned long tmp = (unsigned long)bitmap; + + nbits = min(end - start + 1, BITS_PER_LONG - ebit); + + if (ebit >= BITS_PER_LONG) + continue; + bitmap_clear(&tmp, ebit, nbits); + if (tmp == RADIX_TREE_EXCEPTIONAL_ENTRY) + __radix_tree_delete(root, node, slot); + else + rcu_assign_pointer(*slot, (void *)tmp); + } else if (bitmap) { + nbits = min(end - start + 1, IDA_BITMAP_BITS - bit); + + if (nbits != IDA_BITMAP_BITS) + bitmap_clear(bitmap->bitmap, bit, nbits); + + if (nbits == IDA_BITMAP_BITS || + bitmap_empty(bitmap->bitmap, IDA_BITMAP_BITS)) { + kfree(bitmap); + __radix_tree_delete(root, node, slot); + } + } + } +} +EXPORT_SYMBOL(xb_clear_bit_range); + +/** * xb_test_bit - test a bit in the xbitmap * @xb: the xbitmap tree used to record the bit * @bit: index of the bit to test @@ -143,6 +222,80 @@ bool xb_test_bit(const struct xb *xb, unsigned long bit) } EXPORT_SYMBOL(xb_test_bit); +static unsigned long xb_find_next_bit(struct xb *xb, unsigned long start, + unsigned long end, bool set) +{ + struct radix_tree_root *root = &xb->xbrt; + struct radix_tree_node *node; + void **slot; + struct ida_bitmap *bmap; + unsigned long ret = end + 1; + + for (; start < end; start = (start | (IDA_BITMAP_BITS - 1)) + 1) { + unsigned long index = start / IDA_BITMAP_BITS; + unsigned long bit = start % IDA_BITMAP_BITS; + + bmap = __radix_tree_lookup(root, index, &node, &slot); + if (radix_tree_exception(bmap)) { + unsigned long tmp = (unsigned long)bmap; + unsigned long ebit = bit + 2; + + if (ebit >= BITS_PER_LONG) + continue; + if (set) + ret = find_next_bit(&tmp, BITS_PER_LONG, ebit); + else + ret = find_next_zero_bit(&tmp, BITS_PER_LONG, + ebit); + if (ret < BITS_PER_LONG) + return ret - 2 + IDA_BITMAP_BITS * index; + } else if (bmap) { + if (set) + ret = find_next_bit(bmap->bitmap, + IDA_BITMAP_BITS, bit); + else + ret = find_next_zero_bit(bmap->bitmap, + IDA_BITMAP_BITS, bit); + if (ret < IDA_BITMAP_BITS) + return ret + index * IDA_BITMAP_BITS; + } else if (!bmap && !set) { + return start; + } + } + + return ret; +} + +/** + * xb_find_next_set_bit - find the next set bit in a range + * @xb: the xbitmap to search + * @start: the start of the range, inclusive + * @end: the end of the range, inclusive + * + * Returns: the index of the found bit, or @end + 1 if no such bit is found. + */ +unsigned long xb_find_next_set_bit(struct xb *xb, unsigned long start, + unsigned long end) +{ + return xb_find_next_bit(xb, start, end, 1); +} +EXPORT_SYMBOL(xb_find_next_set_bit); + +/** + * xb_find_next_zero_bit - find the next zero bit in a range + * @xb: the xbitmap to search + * @start: the start of the range, inclusive + * @end: the end of the range, inclusive + * + * Returns: the index of the found bit, or @end + 1 if no such bit is found. + */ +unsigned long xb_find_next_zero_bit(struct xb *xb, unsigned long start, + unsigned long end) +{ + return xb_find_next_bit(xb, start, end, 0); +} +EXPORT_SYMBOL(xb_find_next_zero_bit); + #ifndef __KERNEL__ static DEFINE_XB(xb1); @@ -160,6 +313,31 @@ void xbitmap_check_bit(unsigned long bit) xb_preload_end(); } +static void xbitmap_check_bit_range(void) +{ + /* Set a range of bits */ + assert(!xb_preload_and_set_bit(&xb1, 1060, GFP_KERNEL)); + assert(!xb_preload_and_set_bit(&xb1, 1061, GFP_KERNEL)); + assert(!xb_preload_and_set_bit(&xb1, 1064, GFP_KERNEL)); + assert(!xb_preload_and_set_bit(&xb1, 1065, GFP_KERNEL)); + assert(!xb_preload_and_set_bit(&xb1, 8180, GFP_KERNEL)); + assert(!xb_preload_and_set_bit(&xb1, 8181, GFP_KERNEL)); + assert(!xb_preload_and_set_bit(&xb1, 8190, GFP_KERNEL)); + assert(!xb_preload_and_set_bit(&xb1, 8191, GFP_KERNEL)); + + /* Test a range of bits */ + assert(xb_find_next_set_bit(&xb1, 0, 10000) == 1060); + assert(xb_find_next_zero_bit(&xb1, 1061, 10000) == 1062); + assert(xb_find_next_set_bit(&xb1, 1062, 10000) == 1064); + assert(xb_find_next_zero_bit(&xb1, 1065, 10000) == 1066); + assert(xb_find_next_set_bit(&xb1, 1066, 10000) == 8180); + assert(xb_find_next_zero_bit(&xb1, 8180, 10000) == 8182); + xb_clear_bit_range(&xb1, 0, 20000); + assert(xb_find_next_set_bit(&xb1, 0, 10000) == 10001); + + assert(xb_find_next_zero_bit(&xb1, 20000, 30000) == 20000); +} + void xbitmap_checks(void) { xb_init(&xb1); @@ -171,6 +349,8 @@ void xbitmap_checks(void) xbitmap_check_bit(1025); xbitmap_check_bit((1UL << 63) | (1UL << 24)); xbitmap_check_bit((1UL << 63) | (1UL << 24) | 70); + + xbitmap_check_bit_range(); } int __weak main(void) diff --git a/tools/include/linux/bitmap.h b/tools/include/linux/bitmap.h index ca16027..8d0bc1b 100644 --- a/tools/include/linux/bitmap.h +++ b/tools/include/linux/bitmap.h @@ -37,6 +37,40 @@ static inline void bitmap_zero(unsigned long *dst, int nbits) } } +static inline void __bitmap_clear(unsigned long *map, unsigned int start, + int len) +{ + unsigned long *p = map + BIT_WORD(start); + const unsigned int size = start + len; + int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); + unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); + + while (len - bits_to_clear >= 0) { + *p &= ~mask_to_clear; + len -= bits_to_clear; + bits_to_clear = BITS_PER_LONG; + mask_to_clear = ~0UL; + p++; + } + if (len) { + mask_to_clear &= BITMAP_LAST_WORD_MASK(size); + *p &= ~mask_to_clear; + } +} + +static inline __always_inline void bitmap_clear(unsigned long *map, + unsigned int start, + unsigned int nbits) +{ + if (__builtin_constant_p(nbits) && nbits == 1) + __clear_bit(start, map); + else if (__builtin_constant_p(start & 7) && IS_ALIGNED(start, 8) && + __builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8)) + memset((char *)map + start / 8, 0, nbits / 8); + else + __bitmap_clear(map, start, nbits); +} + static inline void bitmap_fill(unsigned long *dst, unsigned int nbits) { unsigned int nlongs = BITS_TO_LONGS(nbits); diff --git a/tools/include/linux/kernel.h b/tools/include/linux/kernel.h index 0ad8844..3c992ae 100644 --- a/tools/include/linux/kernel.h +++ b/tools/include/linux/kernel.h @@ -13,6 +13,8 @@ #define UINT_MAX (~0U) #endif +#define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0) + #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d)) #define PERF_ALIGN(x, a) __PERF_ALIGN_MASK(x, (typeof(x))(a)-1)

[v18,05/10] xbitmap: add more operations

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