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Date: Thu, 19 Jun 2014 03:58:36 +0200 From: Michal Nazarewicz <mina86@...a86.com> To: Peter Zijlstra <peterz@...radead.org>, Thomas Gleixner <tglx@...utronix.de> Cc: x86@...nel.org, linux-kernel@...r.kernel.org, Michal Nazarewicz <mina86@...a86.com> Subject: [PATCH] x86: tsc: get rid of custom DIV_ROUND When invoced for positive values, DIV_ROUND macro defined in arch/x86/kernel/tsc.c behaves exactly like DIV_ROUND_CLOSEST from include/linux/kernel.h file, so remove the custom macro in favour of the shared one. Signed-off-by: Michal Nazarewicz <mina86@...a86.com> --- arch/x86/kernel/tsc.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) No changes after compilation: $ ll tsc.o.* -rw------- 1 mpn eng 46497 Jun 19 03:54 tsc.o.after -rw------- 1 mpn eng 46497 Jun 19 03:55 tsc.o.before $ objdump -d tsc.o.before >tsc.s.before $ objdump -d tsc.o.after >tsc.s.after $ diff -u tsc.s.before tsc.s.after --- tsc.s.before 2014-06-19 03:56:54.880545041 +0200 +++ tsc.s.after 2014-06-19 03:56:54.884545079 +0200 @@ -1,5 +1,5 @@ -tsc.o.before: file format elf64-x86-64 +tsc.o.after: file format elf64-x86-64 Disassembly of section .text: $ diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 57e5ce1..02f21c0 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -234,9 +234,6 @@ static inline unsigned long long cycles_2_ns(unsigned long long cyc) return ns; } -/* XXX surely we already have this someplace in the kernel?! */ -#define DIV_ROUND(n, d) (((n) + ((d) / 2)) / (d)) - static void set_cyc2ns_scale(unsigned long cpu_khz, int cpu) { unsigned long long tsc_now, ns_now; @@ -259,7 +256,8 @@ static void set_cyc2ns_scale(unsigned long cpu_khz, int cpu) * time function is continuous; see the comment near struct * cyc2ns_data. */ - data->cyc2ns_mul = DIV_ROUND(NSEC_PER_MSEC << CYC2NS_SCALE_FACTOR, cpu_khz); + data->cyc2ns_mul = DIV_ROUND_CLOSEST( + NSEC_PER_MSEC << CYC2NS_SCALE_FACTOR, cpu_khz); data->cyc2ns_shift = CYC2NS_SCALE_FACTOR; data->cyc2ns_offset = ns_now - mul_u64_u32_shr(tsc_now, data->cyc2ns_mul, CYC2NS_SCALE_FACTOR); -- 2.0.0.526.g5318336 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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