diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/cpumask.c | 9 | ||||
| -rw-r--r-- | lib/find_bit.c | 59 | ||||
| -rw-r--r-- | lib/find_bit_benchmark.c | 25 |
3 files changed, 72 insertions, 21 deletions
diff --git a/lib/cpumask.c b/lib/cpumask.c index 35fe142..beca624 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 6ed74f7..ee3df93 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 67b1923..5985a25 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 |
