From: Jiang, Yunhong <yunhong.jiang@intel.com>
Date: Fri, 28 Oct 2016 23:29:05 +0000 (+0000)
Subject: Merge "Fix imprecise timer interrupts by  eliminating TSC clockevents frequency round... 
X-Git-Tag: danube.1.0~28
X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=commitdiff_plain;h=f2e379228d244be691bee350da1cb3d820cb6dfb;hp=c0946a21d3e299d73620b6fee2327f5f0f6ebb32;p=kvmfornfv.git

Merge "Fix imprecise timer interrupts by  eliminating TSC clockevents frequency roundoff error"
---

diff --git a/kernel/arch/x86/kernel/apic/apic.c b/kernel/arch/x86/kernel/apic/apic.c
index 2f69e3b18..d2eee3e1b 100644
--- a/kernel/arch/x86/kernel/apic/apic.c
+++ b/kernel/arch/x86/kernel/apic/apic.c
@@ -305,7 +305,7 @@ int lapic_get_maxlvt(void)
 
 /* Clock divisor */
 #define APIC_DIVISOR 16
-#define TSC_DIVISOR  32
+#define TSC_DIVISOR  8
 
 /*
  * This function sets up the local APIC timer, with a timeout of
@@ -557,7 +557,7 @@ static void setup_APIC_timer(void)
 				    CLOCK_EVT_FEAT_DUMMY);
 		levt->set_next_event = lapic_next_deadline;
 		clockevents_config_and_register(levt,
-						(tsc_khz / TSC_DIVISOR) * 1000,
+						tsc_khz * (1000 / TSC_DIVISOR),
 						0xF, ~0UL);
 	} else
 		clockevents_register_device(levt);