Commit-ID: 9cfa1a0279e22063a727fd204a75cf3672860d83 Gitweb: http://git.kernel.org/tip/9cfa1a0279e22063a727fd204a75cf3672860d83 Author: Andy Lutomirski <[email protected]> AuthorDate: Thu, 25 Jun 2015 18:44:00 +0200 Committer: Ingo Molnar <[email protected]> CommitDate: Mon, 6 Jul 2015 15:23:27 +0200
x86/asm/tsc: Use the full 64-bit TSC in delay_tsc() As a very minor optimization, delay_tsc() was only using the low 32 bits of the TSC. It's a delay function, so just use the whole thing. Signed-off-by: Andy Lutomirski <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Huang Rui <[email protected]> Cc: John Stultz <[email protected]> Cc: Len Brown <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ralf Baechle <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: kvm ML <[email protected]> Link: http://lkml.kernel.org/r/bd1a277c71321b67c4794970cb5ace05efe21ab6.1434501121.git.l...@kernel.org Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/lib/delay.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/lib/delay.c b/arch/x86/lib/delay.c index 9a52ad0..35115f3 100644 --- a/arch/x86/lib/delay.c +++ b/arch/x86/lib/delay.c @@ -49,16 +49,16 @@ static void delay_loop(unsigned long loops) /* TSC based delay: */ static void delay_tsc(unsigned long __loops) { - u32 bclock, now, loops = __loops; + u64 bclock, now, loops = __loops; int cpu; preempt_disable(); cpu = smp_processor_id(); rdtsc_barrier(); - rdtscl(bclock); + bclock = native_read_tsc(); for (;;) { rdtsc_barrier(); - rdtscl(now); + now = native_read_tsc(); if ((now - bclock) >= loops) break; @@ -80,7 +80,7 @@ static void delay_tsc(unsigned long __loops) loops -= (now - bclock); cpu = smp_processor_id(); rdtsc_barrier(); - rdtscl(bclock); + bclock = native_read_tsc(); } } preempt_enable(); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
