From ccb64941f375a6eb21b1b20136730eb7d1716068 Mon Sep 17 00:00:00 2001
From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Date: Mon, 11 Sep 2017 14:51:11 -0400
Subject: [PATCH] x86/timers: Move simple_udelay_calibration() past
kvmclock_init()
simple_udelay_calibration() relies on x86_platform's calibration ops.
For KVM these ops are set late in setup_arch() and so
simple_udelay_calibration() ends up using native version.
Besides being possibly incorrect, this significantly increases kernel
boot time. For example, on my laptop executing start_kernel() by a guest
takes ~10 times more than when KVM's ops are used.
Since early_xdbc_setup_hardware() relies on calibration having been
performed move it too.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: baolu.lu@linux.intel.com
Link: https://lkml.kernel.org/r/20170911185111.20636-1-boris.ostrovsky@oracle.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/kernel/setup.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index c63d2b4dd5c8c..b40311027c15e 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1029,8 +1029,6 @@ void __init setup_arch(char **cmdline_p)
*/
init_hypervisor_platform();
- tsc_early_delay_calibrate();
-
x86_init.resources.probe_roms();
/* after parse_early_param, so could debug it */
@@ -1115,9 +1113,6 @@ void __init setup_arch(char **cmdline_p)
memblock_set_current_limit(ISA_END_ADDRESS);
e820__memblock_setup();
- if (!early_xdbc_setup_hardware())
- early_xdbc_register_console();
-
reserve_bios_regions();
if (efi_enabled(EFI_MEMMAP)) {
@@ -1223,6 +1218,10 @@ void __init setup_arch(char **cmdline_p)
kvmclock_init();
#endif
+ tsc_early_delay_calibrate();
+ if (!early_xdbc_setup_hardware())
+ early_xdbc_register_console();
+
x86_init.paging.pagetable_init();
kasan_init();
--
2.30.2