Messages in this thread Patch in this message | | | From | Dimitris Papastamos <> | Subject | [PATCH] regmap: Optimize the lookup path to use binary search | Date | Mon, 3 Oct 2011 10:50:14 +0100 |
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Since there are more lookups than insertions in a typical scenario, optimize the linear search into a binary search. For this to work, we need to keep reg_defaults sorted upon insertions, for now be lazy and use sort().
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com> --- drivers/base/regmap/regcache.c | 29 ++++++++++++++++++++++++----- 1 files changed, 24 insertions(+), 5 deletions(-)
diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c index f32c08c..b10e38f 100644 --- a/drivers/base/regmap/regcache.c +++ b/drivers/base/regmap/regcache.c @@ -12,6 +12,7 @@ #include <linux/slab.h> #include <trace/events/regmap.h> +#include <linux/sort.h> #include "internal.h" @@ -356,14 +357,30 @@ unsigned int regcache_get_val(const void *base, unsigned int idx, int regcache_lookup_reg(struct regmap *map, unsigned int reg) { - unsigned int i; - - for (i = 0; i < map->num_reg_defaults; i++) - if (map->reg_defaults[i].reg == reg) - return i; + unsigned int min, max, index; + + min = 0; + max = map->num_reg_defaults - 1; + do { + index = (min + max) / 2; + if (map->reg_defaults[index].reg == reg) + return index; + if (map->reg_defaults[index].reg < reg) + min = index + 1; + else + max = index; + } while (min <= max); return -1; } +static int regcache_insert_cmp(const void *a, const void *b) +{ + const struct reg_default *_a = a; + const struct reg_default *_b = b; + + return _a->reg - _b->reg; +} + int regcache_insert_reg(struct regmap *map, unsigned int reg, unsigned int val) { @@ -378,5 +395,7 @@ int regcache_insert_reg(struct regmap *map, unsigned int reg, map->num_reg_defaults++; map->reg_defaults[map->num_reg_defaults - 1].reg = reg; map->reg_defaults[map->num_reg_defaults - 1].def = val; + sort(map->reg_defaults, map->num_reg_defaults, + sizeof(struct reg_default), regcache_insert_cmp, NULL); return 0; } -- 1.7.6.4
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