From: Alexey Dobriyan <adobriyan@xxxxxxxxx> Subject: kstrtox: uninline everything I've made a mistake of looking into lib/kstrtox.o code generation. The only function remotely performance critical is _parse_integer() (via /proc/*/map_files/*), everything else is not. Uninline everything, shrink lib/kstrtox.o by ~20 % ! Space savings on x86_64: add/remove: 0/0 grow/shrink: 0/23 up/down: 0/-1269 (-1269 !!!) Function old new delta kstrtoull 16 13 -3 kstrtouint 59 48 -11 kstrtou8 60 49 -11 kstrtou16 61 50 -11 _kstrtoul 46 35 -11 kstrtoull_from_user 95 83 -12 kstrtoul_from_user 95 83 -12 kstrtoll 93 80 -13 kstrtouint_from_user 124 83 -41 kstrtou8_from_user 125 83 -42 kstrtou16_from_user 126 83 -43 kstrtos8 101 50 -51 kstrtos16 102 51 -51 kstrtoint 100 49 -51 _kstrtol 93 35 -58 kstrtobool_from_user 156 75 -81 kstrtoll_from_user 165 83 -82 kstrtol_from_user 165 83 -82 kstrtoint_from_user 172 83 -89 kstrtos8_from_user 173 83 -90 kstrtos16_from_user 174 83 -91 _parse_integer 136 10 -126 _kstrtoull 308 101 -207 Total: Before=3421236, After=3419967, chg -0.04% Link: https://lkml.kernel.org/r/YZDsFDhHst4m2Pnt@localhost.localdomain Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- lib/kstrtox.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/lib/kstrtox.c~kstrtox-uninline-everything +++ a/lib/kstrtox.c @@ -22,6 +22,7 @@ #include "kstrtox.h" +noinline const char *_parse_integer_fixup_radix(const char *s, unsigned int *base) { if (*base == 0) { @@ -47,6 +48,7 @@ const char *_parse_integer_fixup_radix(c * * Don't you dare use this function. */ +noinline unsigned int _parse_integer_limit(const char *s, unsigned int base, unsigned long long *p, size_t max_chars) { @@ -85,6 +87,7 @@ unsigned int _parse_integer_limit(const return rv; } +noinline unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long *p) { return _parse_integer_limit(s, base, p, INT_MAX); @@ -125,6 +128,7 @@ static int _kstrtoull(const char *s, uns * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. * Preferred over simple_strtoull(). Return code must be checked. */ +noinline int kstrtoull(const char *s, unsigned int base, unsigned long long *res) { if (s[0] == '+') @@ -148,6 +152,7 @@ EXPORT_SYMBOL(kstrtoull); * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. * Preferred over simple_strtoll(). Return code must be checked. */ +noinline int kstrtoll(const char *s, unsigned int base, long long *res) { unsigned long long tmp; @@ -219,6 +224,7 @@ EXPORT_SYMBOL(_kstrtol); * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. * Preferred over simple_strtoul(). Return code must be checked. */ +noinline int kstrtouint(const char *s, unsigned int base, unsigned int *res) { unsigned long long tmp; @@ -249,6 +255,7 @@ EXPORT_SYMBOL(kstrtouint); * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. * Preferred over simple_strtol(). Return code must be checked. */ +noinline int kstrtoint(const char *s, unsigned int base, int *res) { long long tmp; @@ -264,6 +271,7 @@ int kstrtoint(const char *s, unsigned in } EXPORT_SYMBOL(kstrtoint); +noinline int kstrtou16(const char *s, unsigned int base, u16 *res) { unsigned long long tmp; @@ -279,6 +287,7 @@ int kstrtou16(const char *s, unsigned in } EXPORT_SYMBOL(kstrtou16); +noinline int kstrtos16(const char *s, unsigned int base, s16 *res) { long long tmp; @@ -294,6 +303,7 @@ int kstrtos16(const char *s, unsigned in } EXPORT_SYMBOL(kstrtos16); +noinline int kstrtou8(const char *s, unsigned int base, u8 *res) { unsigned long long tmp; @@ -309,6 +319,7 @@ int kstrtou8(const char *s, unsigned int } EXPORT_SYMBOL(kstrtou8); +noinline int kstrtos8(const char *s, unsigned int base, s8 *res) { long long tmp; @@ -333,6 +344,7 @@ EXPORT_SYMBOL(kstrtos8); * [oO][NnFf] for "on" and "off". Otherwise it will return -EINVAL. Value * pointed to by res is updated upon finding a match. */ +noinline int kstrtobool(const char *s, bool *res) { if (!s) _
