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
Cc: david@redhat.com, cornelia.huck@de.ibm.com,
mgorman@techsingularity.net, aarcange@redhat.com,
amit.shah@redhat.com, pbonzini@redhat.com, willy@infradead.org,
wei.w.wang@intel.com, liliang.opensource@gmail.com,
yang.zhang.wz@gmail.com, quan.xu@aliyun.com
Subject: [PATCH v14 2/5] lib/xbitmap: add xb_find_next_bit() and xb_zero()
Date: Thu, 17 Aug 2017 11:26:53 +0800 [thread overview]
Message-ID: <1502940416-42944-3-git-send-email-wei.w.wang@intel.com> (raw)
In-Reply-To: <1502940416-42944-1-git-send-email-wei.w.wang@intel.com>
xb_find_next_bit() is used to find the next "1" or "0" bit in the
given range. xb_zero() is used to zero the given range of bits.
Signed-off-by: Wei Wang <wei.w.wang@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
---
include/linux/xbitmap.h | 3 +++
lib/xbitmap.c | 39 +++++++++++++++++++++++++++++++++++++++
2 files changed, 42 insertions(+)
diff --git a/include/linux/xbitmap.h b/include/linux/xbitmap.h
index 5edbf84..739d08c 100644
--- a/include/linux/xbitmap.h
+++ b/include/linux/xbitmap.h
@@ -38,6 +38,9 @@ static inline void xb_init(struct xb *xb)
int xb_set_bit(struct xb *xb, unsigned long bit);
bool xb_test_bit(const struct xb *xb, unsigned long bit);
void xb_clear_bit(struct xb *xb, unsigned long bit);
+void xb_zero(struct xb *xb, unsigned long start, unsigned long end);
+unsigned long xb_find_next_bit(struct xb *xb, unsigned long start,
+ unsigned long end, bool set);
/* Check if the xb tree is empty */
static inline bool xb_is_empty(const struct xb *xb)
diff --git a/lib/xbitmap.c b/lib/xbitmap.c
index cc766d9..2267ac2 100644
--- a/lib/xbitmap.c
+++ b/lib/xbitmap.c
@@ -174,3 +174,42 @@ void xb_preload(gfp_t gfp)
}
}
EXPORT_SYMBOL(xb_preload);
+
+/**
+ * xb_zero - zero a range of bits in the xbitmap
+ * @xb: the xbitmap that the bits reside in
+ * @start: the start of the range, inclusive
+ * @end: the end of the range, inclusive
+ */
+void xb_zero(struct xb *xb, unsigned long start, unsigned long end)
+{
+ unsigned long i;
+
+ for (i = start; i <= end; i++)
+ xb_clear_bit(xb, i);
+}
+EXPORT_SYMBOL(xb_zero);
+
+/**
+ * xb_find_next_bit - find next 1 or 0 in the give range of bits
+ * @xb: the xbitmap that the bits reside in
+ * @start: the start of the range, inclusive
+ * @end: the end of the range, inclusive
+ * @set: the polarity (1 or 0) of the next bit to find
+ *
+ * Return the index of the found bit in the xbitmap. If the returned index
+ * exceeds @end, it indicates that no such bit is found in the given range.
+ */
+unsigned long xb_find_next_bit(struct xb *xb, unsigned long start,
+ unsigned long end, bool set)
+{
+ unsigned long i;
+
+ for (i = start; i <= end; i++) {
+ if (xb_test_bit(xb, i) == set)
+ break;
+ }
+
+ return i;
+}
+EXPORT_SYMBOL(xb_find_next_bit);
--
2.7.4
--
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next prev parent reply other threads:[~2017-08-17 3:38 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-17 3:26 [PATCH v14 0/5] Virtio-balloon Enhancement Wei Wang
2017-08-17 3:26 ` [PATCH v14 1/5] lib/xbitmap: Introduce xbitmap Wei Wang
2017-08-19 20:30 ` kbuild test robot
2017-08-17 3:26 ` Wei Wang [this message]
2017-08-17 3:26 ` [PATCH v14 3/5] virtio-balloon: VIRTIO_BALLOON_F_SG Wei Wang
2017-08-18 2:22 ` Michael S. Tsirkin
2017-08-18 7:39 ` Wei Wang
2017-08-21 20:22 ` Michael S. Tsirkin
2017-08-19 21:37 ` kbuild test robot
2017-08-17 3:26 ` [PATCH v14 4/5] mm: support reporting free page blocks Wei Wang
2017-08-18 13:46 ` Michal Hocko
2017-08-21 6:12 ` Wei Wang
2017-08-21 6:14 ` Michal Hocko
2017-08-18 17:23 ` Michael S. Tsirkin
2017-08-21 6:18 ` Michal Hocko
2017-08-17 3:26 ` [PATCH v14 5/5] virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_VQ Wei Wang
2017-08-18 2:13 ` Michael S. Tsirkin
2017-08-18 8:41 ` Wei Wang
2017-08-18 18:26 ` Michael S. Tsirkin
2017-08-21 5:21 ` Wei Wang
2017-08-18 2:28 ` Michael S. Tsirkin
2017-08-18 8:36 ` Wei Wang
2017-08-18 18:10 ` Michael S. Tsirkin
2017-08-21 5:28 ` [virtio-dev] " Wei Wang
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