[tip:x86/timers] x86/timers: Move simple_udelay_calibration() past kvmclock_init()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Commit-ID:  ccb64941f375a6eb21b1b20136730eb7d1716068
Gitweb:     http://git.kernel.org/tip/ccb64941f375a6eb21b1b20136730eb7d1716068
Author:     Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
AuthorDate: Mon, 11 Sep 2017 14:51:11 -0400
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Mon, 25 Sep 2017 15:22:45 +0200

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@xxxxxxxxxx>
Cc: baolu.lu@xxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/20170911185111.20636-1-boris.ostrovsky@xxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

---
 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 c63d2b4..b403110 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();
--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Stable Commits]     [Linux Stable Kernel]     [Linux Kernel]     [Linux USB Devel]     [Linux Video &Media]     [Linux Audio Users]     [Yosemite News]     [Linux SCSI]

  Powered by Linux