From f22ef333c32cc683922d7e3361a83ebc31b2ac6d Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Fri, 8 Sep 2017 16:17:15 -0700 Subject: cpumask: make cpumask_next() out-of-line Every for_each_XXX_cpu() invocation calls cpumask_next() which is an inline function: static inline unsigned int cpumask_next(int n, const struct cpumask *srcp) { /* -1 is a legal arg here. */ if (n != -1) cpumask_check(n); return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n + 1); } However! find_next_bit() is regular out-of-line function which means "nr_cpu_ids" load and increment happen at the caller resulting in a lot of bloat x86_64 defconfig: add/remove: 3/0 grow/shrink: 8/373 up/down: 155/-5668 (-5513) x86_64 allyesconfig-ish: add/remove: 3/1 grow/shrink: 57/634 up/down: 3515/-28177 (-24662) !!! Some archs redefine find_next_bit() but it is OK: m68k inline but SMP is not supported arm out-of-line unicore32 out-of-line Function call will happen anyway, so move load and increment into callee. Link: http://lkml.kernel.org/r/20170824230010.GA1593@avx2 Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/cpumask.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'lib') diff --git a/lib/cpumask.c b/lib/cpumask.c index 4731a0895760..8b1a1bd77539 100644 --- a/lib/cpumask.c +++ b/lib/cpumask.c @@ -5,6 +5,22 @@ #include #include +/** + * cpumask_next - get the next cpu in a cpumask + * @n: the cpu prior to the place to search (ie. return will be > @n) + * @srcp: the cpumask pointer + * + * Returns >= nr_cpu_ids if no further cpus set. + */ +unsigned int cpumask_next(int n, const struct cpumask *srcp) +{ + /* -1 is a legal arg here. */ + if (n != -1) + cpumask_check(n); + return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n + 1); +} +EXPORT_SYMBOL(cpumask_next); + /** * cpumask_next_and - get the next cpu in *src1p & *src2p * @n: the cpu prior to the place to search (ie. return will be > @n) -- cgit