diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig | 3 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 32 | ||||
| -rw-r--r-- | lib/Makefile | 1 | ||||
| -rw-r--r-- | lib/cpumask.c | 11 | ||||
| -rw-r--r-- | lib/rational.c | 62 |
5 files changed, 100 insertions, 9 deletions
diff --git a/lib/Kconfig b/lib/Kconfig index 8ade0a7a91e0..9960be04cbbe 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -10,6 +10,9 @@ menu "Library routines" config BITREVERSE tristate +config RATIONAL + boolean + config GENERIC_FIND_FIRST_BIT bool diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 6cdcf38f2da9..116a35051be6 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -336,6 +336,38 @@ config SLUB_STATS out which slabs are relevant to a particular load. Try running: slabinfo -DA +config DEBUG_KMEMLEAK + bool "Kernel memory leak detector" + depends on DEBUG_KERNEL && EXPERIMENTAL && (X86 || ARM) && \ + !MEMORY_HOTPLUG + select DEBUG_SLAB if SLAB + select SLUB_DEBUG if SLUB + select DEBUG_FS if SYSFS + select STACKTRACE if STACKTRACE_SUPPORT + select KALLSYMS + help + Say Y here if you want to enable the memory leak + detector. The memory allocation/freeing is traced in a way + similar to the Boehm's conservative garbage collector, the + difference being that the orphan objects are not freed but + only shown in /sys/kernel/debug/kmemleak. Enabling this + feature will introduce an overhead to memory + allocations. See Documentation/kmemleak.txt for more + details. + + In order to access the kmemleak file, debugfs needs to be + mounted (usually at /sys/kernel/debug). + +config DEBUG_KMEMLEAK_TEST + tristate "Simple test for the kernel memory leak detector" + depends on DEBUG_KMEMLEAK + help + Say Y or M here to build a test for the kernel memory leak + detector. This option enables a module that explicitly leaks + memory. + + If unsure, say N. + config DEBUG_PREEMPT bool "Debug preemptible kernel" depends on DEBUG_KERNEL && PREEMPT && (TRACE_IRQFLAGS_SUPPORT || PPC64) diff --git a/lib/Makefile b/lib/Makefile index 33a40e40e3ee..1f6edefebffe 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -50,6 +50,7 @@ ifneq ($(CONFIG_HAVE_DEC_LOCK),y) endif obj-$(CONFIG_BITREVERSE) += bitrev.o +obj-$(CONFIG_RATIONAL) += rational.o obj-$(CONFIG_CRC_CCITT) += crc-ccitt.o obj-$(CONFIG_CRC16) += crc16.o obj-$(CONFIG_CRC_T10DIF)+= crc-t10dif.o diff --git a/lib/cpumask.c b/lib/cpumask.c index eb23aaa0c7b8..7bb4142a502f 100644 --- a/lib/cpumask.c +++ b/lib/cpumask.c @@ -92,15 +92,8 @@ int cpumask_any_but(const struct cpumask *mask, unsigned int cpu) */ bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node) { - if (likely(slab_is_available())) - *mask = kmalloc_node(cpumask_size(), flags, node); - else { -#ifdef CONFIG_DEBUG_PER_CPU_MAPS - printk(KERN_ERR - "=> alloc_cpumask_var: kmalloc not available!\n"); -#endif - *mask = NULL; - } + *mask = kmalloc_node(cpumask_size(), flags, node); + #ifdef CONFIG_DEBUG_PER_CPU_MAPS if (!*mask) { printk(KERN_ERR "=> alloc_cpumask_var: failed!\n"); diff --git a/lib/rational.c b/lib/rational.c new file mode 100644 index 000000000000..b3c099b5478e --- /dev/null +++ b/lib/rational.c @@ -0,0 +1,62 @@ +/* + * rational fractions + * + * Copyright (C) 2009 emlix GmbH, Oskar Schirmer <os@emlix.com> + * + * helper functions when coping with rational numbers + */ + +#include <linux/rational.h> + +/* + * calculate best rational approximation for a given fraction + * taking into account restricted register size, e.g. to find + * appropriate values for a pll with 5 bit denominator and + * 8 bit numerator register fields, trying to set up with a + * frequency ratio of 3.1415, one would say: + * + * rational_best_approximation(31415, 10000, + * (1 << 8) - 1, (1 << 5) - 1, &n, &d); + * + * you may look at given_numerator as a fixed point number, + * with the fractional part size described in given_denominator. + * + * for theoretical background, see: + * http://en.wikipedia.org/wiki/Continued_fraction + */ + +void rational_best_approximation( + unsigned long given_numerator, unsigned long given_denominator, + unsigned long max_numerator, unsigned long max_denominator, + unsigned long *best_numerator, unsigned long *best_denominator) +{ + unsigned long n, d, n0, d0, n1, d1; + n = given_numerator; + d = given_denominator; + n0 = d1 = 0; + n1 = d0 = 1; + for (;;) { + unsigned long t, a; + if ((n1 > max_numerator) || (d1 > max_denominator)) { + n1 = n0; + d1 = d0; + break; + } + if (d == 0) + break; + t = d; + a = n / d; + d = n % d; + n = t; + t = n0 + a * n1; + n0 = n1; + n1 = t; + t = d0 + a * d1; + d0 = d1; + d1 = t; + } + *best_numerator = n1; + *best_denominator = d1; +} + +EXPORT_SYMBOL(rational_best_approximation); |