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-rw-r--r--lib/cpumask.c9
-rw-r--r--lib/find_bit.c59
-rw-r--r--lib/find_bit_benchmark.c25
3 files changed, 72 insertions, 21 deletions
diff --git a/lib/cpumask.c b/lib/cpumask.c
index 35fe142ebb5e..beca6244671a 100644
--- a/lib/cpumask.c
+++ b/lib/cpumask.c
@@ -33,10 +33,11 @@ EXPORT_SYMBOL(cpumask_next);
int cpumask_next_and(int n, const struct cpumask *src1p,
const struct cpumask *src2p)
{
- while ((n = cpumask_next(n, src1p)) < nr_cpu_ids)
- if (cpumask_test_cpu(n, src2p))
- break;
- return n;
+ /* -1 is a legal arg here. */
+ if (n != -1)
+ cpumask_check(n);
+ return find_next_and_bit(cpumask_bits(src1p), cpumask_bits(src2p),
+ nr_cpumask_bits, n + 1);
}
EXPORT_SYMBOL(cpumask_next_and);
diff --git a/lib/find_bit.c b/lib/find_bit.c
index 6ed74f78380c..ee3df93ba69a 100644
--- a/lib/find_bit.c
+++ b/lib/find_bit.c
@@ -21,22 +21,29 @@
#include <linux/export.h>
#include <linux/kernel.h>
-#if !defined(find_next_bit) || !defined(find_next_zero_bit)
+#if !defined(find_next_bit) || !defined(find_next_zero_bit) || \
+ !defined(find_next_and_bit)
/*
- * This is a common helper function for find_next_bit and
- * find_next_zero_bit. The difference is the "invert" argument, which
- * is XORed with each fetched word before searching it for one bits.
+ * This is a common helper function for find_next_bit, find_next_zero_bit, and
+ * find_next_and_bit. The differences are:
+ * - The "invert" argument, which is XORed with each fetched word before
+ * searching it for one bits.
+ * - The optional "addr2", which is anded with "addr1" if present.
*/
-static unsigned long _find_next_bit(const unsigned long *addr,
- unsigned long nbits, unsigned long start, unsigned long invert)
+static inline unsigned long _find_next_bit(const unsigned long *addr1,
+ const unsigned long *addr2, unsigned long nbits,
+ unsigned long start, unsigned long invert)
{
unsigned long tmp;
if (unlikely(start >= nbits))
return nbits;
- tmp = addr[start / BITS_PER_LONG] ^ invert;
+ tmp = addr1[start / BITS_PER_LONG];
+ if (addr2)
+ tmp &= addr2[start / BITS_PER_LONG];
+ tmp ^= invert;
/* Handle 1st word. */
tmp &= BITMAP_FIRST_WORD_MASK(start);
@@ -47,7 +54,10 @@ static unsigned long _find_next_bit(const unsigned long *addr,
if (start >= nbits)
return nbits;
- tmp = addr[start / BITS_PER_LONG] ^ invert;
+ tmp = addr1[start / BITS_PER_LONG];
+ if (addr2)
+ tmp &= addr2[start / BITS_PER_LONG];
+ tmp ^= invert;
}
return min(start + __ffs(tmp), nbits);
@@ -61,7 +71,7 @@ static unsigned long _find_next_bit(const unsigned long *addr,
unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
unsigned long offset)
{
- return _find_next_bit(addr, size, offset, 0UL);
+ return _find_next_bit(addr, NULL, size, offset, 0UL);
}
EXPORT_SYMBOL(find_next_bit);
#endif
@@ -70,11 +80,21 @@ EXPORT_SYMBOL(find_next_bit);
unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
unsigned long offset)
{
- return _find_next_bit(addr, size, offset, ~0UL);
+ return _find_next_bit(addr, NULL, size, offset, ~0UL);
}
EXPORT_SYMBOL(find_next_zero_bit);
#endif
+#if !defined(find_next_and_bit)
+unsigned long find_next_and_bit(const unsigned long *addr1,
+ const unsigned long *addr2, unsigned long size,
+ unsigned long offset)
+{
+ return _find_next_bit(addr1, addr2, size, offset, 0UL);
+}
+EXPORT_SYMBOL(find_next_and_bit);
+#endif
+
#ifndef find_first_bit
/*
* Find the first set bit in a memory region.
@@ -146,15 +166,19 @@ static inline unsigned long ext2_swab(const unsigned long y)
}
#if !defined(find_next_bit_le) || !defined(find_next_zero_bit_le)
-static unsigned long _find_next_bit_le(const unsigned long *addr,
- unsigned long nbits, unsigned long start, unsigned long invert)
+static inline unsigned long _find_next_bit_le(const unsigned long *addr1,
+ const unsigned long *addr2, unsigned long nbits,
+ unsigned long start, unsigned long invert)
{
unsigned long tmp;
if (unlikely(start >= nbits))
return nbits;
- tmp = addr[start / BITS_PER_LONG] ^ invert;
+ tmp = addr1[start / BITS_PER_LONG];
+ if (addr2)
+ tmp &= addr2[start / BITS_PER_LONG];
+ tmp ^= invert;
/* Handle 1st word. */
tmp &= ext2_swab(BITMAP_FIRST_WORD_MASK(start));
@@ -165,7 +189,10 @@ static unsigned long _find_next_bit_le(const unsigned long *addr,
if (start >= nbits)
return nbits;
- tmp = addr[start / BITS_PER_LONG] ^ invert;
+ tmp = addr1[start / BITS_PER_LONG];
+ if (addr2)
+ tmp &= addr2[start / BITS_PER_LONG];
+ tmp ^= invert;
}
return min(start + __ffs(ext2_swab(tmp)), nbits);
@@ -176,7 +203,7 @@ static unsigned long _find_next_bit_le(const unsigned long *addr,
unsigned long find_next_zero_bit_le(const void *addr, unsigned
long size, unsigned long offset)
{
- return _find_next_bit_le(addr, size, offset, ~0UL);
+ return _find_next_bit_le(addr, NULL, size, offset, ~0UL);
}
EXPORT_SYMBOL(find_next_zero_bit_le);
#endif
@@ -185,7 +212,7 @@ EXPORT_SYMBOL(find_next_zero_bit_le);
unsigned long find_next_bit_le(const void *addr, unsigned
long size, unsigned long offset)
{
- return _find_next_bit_le(addr, size, offset, 0UL);
+ return _find_next_bit_le(addr, NULL, size, offset, 0UL);
}
EXPORT_SYMBOL(find_next_bit_le);
#endif
diff --git a/lib/find_bit_benchmark.c b/lib/find_bit_benchmark.c
index 67b19233c28f..5985a25e6cbc 100644
--- a/lib/find_bit_benchmark.c
+++ b/lib/find_bit_benchmark.c
@@ -35,6 +35,7 @@
#define SPARSE 500
static DECLARE_BITMAP(bitmap, BITMAP_LEN) __initdata;
+static DECLARE_BITMAP(bitmap2, BITMAP_LEN) __initdata;
/*
* This is Schlemiel the Painter's algorithm. It should be called after
@@ -103,6 +104,22 @@ static int __init test_find_last_bit(const void *bitmap, unsigned long len)
return 0;
}
+static int __init test_find_next_and_bit(const void *bitmap,
+ const void *bitmap2, unsigned long len)
+{
+ unsigned long i, cnt;
+ cycles_t cycles;
+
+ cycles = get_cycles();
+ for (cnt = i = 0; i < BITMAP_LEN; cnt++)
+ i = find_next_and_bit(bitmap, bitmap2, BITMAP_LEN, i+1);
+ cycles = get_cycles() - cycles;
+ pr_err("find_next_and_bit:\t\t%llu cycles, %ld iterations\n",
+ (u64)cycles, cnt);
+
+ return 0;
+}
+
static int __init find_bit_test(void)
{
unsigned long nbits = BITMAP_LEN / SPARSE;
@@ -110,23 +127,29 @@ static int __init find_bit_test(void)
pr_err("\nStart testing find_bit() with random-filled bitmap\n");
get_random_bytes(bitmap, sizeof(bitmap));
+ get_random_bytes(bitmap2, sizeof(bitmap2));
test_find_next_bit(bitmap, BITMAP_LEN);
test_find_next_zero_bit(bitmap, BITMAP_LEN);
test_find_last_bit(bitmap, BITMAP_LEN);
test_find_first_bit(bitmap, BITMAP_LEN);
+ test_find_next_and_bit(bitmap, bitmap2, BITMAP_LEN);
pr_err("\nStart testing find_bit() with sparse bitmap\n");
bitmap_zero(bitmap, BITMAP_LEN);
+ bitmap_zero(bitmap2, BITMAP_LEN);
- while (nbits--)
+ while (nbits--) {
__set_bit(prandom_u32() % BITMAP_LEN, bitmap);
+ __set_bit(prandom_u32() % BITMAP_LEN, bitmap2);
+ }
test_find_next_bit(bitmap, BITMAP_LEN);
test_find_next_zero_bit(bitmap, BITMAP_LEN);
test_find_last_bit(bitmap, BITMAP_LEN);
test_find_first_bit(bitmap, BITMAP_LEN);
+ test_find_next_and_bit(bitmap, bitmap2, BITMAP_LEN);
/*
* Everything is OK. Return error just to let user run benchmark