[PATCH 0/2] Two cleanup patches

[PATCH 0/2] Two cleanup patches

[Dou Liyang]

Here are two cleanup patches, When I test the early boot time stamps
with tip tree today.

Dou Liyang (2):
  x86/tsc: Avoid a double call if tsc can initialize earlier.
  x86/kvmclock: Mark kvm_get_preset_lpj() as __init

 arch/x86/kernel/kvmclock.c |  2 +-
 arch/x86/kernel/tsc.c      | 22 ++++++++++++----------
 2 files changed, 13 insertions(+), 11 deletions(-)

-- 
2.14.3

[PATCH 1/2] x86/tsc: Avoid a double call if TSC initializes earlier.

[Dou Liyang]

static_branch_enable(&__use_tsc) may be called twice in common case, that
is redundant. And there are also some common functions both in
tsc_early_init() and tsc_init().

Move them into a separate helper function, only call it once.
Also fix comments:
 -s/authorative/authoritative
 -s/cyc2ns_init/tsc_init

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
---
 arch/x86/kernel/tsc.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 02e416b87ac1..ba0a6b6e0726 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -182,7 +182,7 @@ static void __init cyc2ns_init_boot_cpu(void)
 }
 
 /*
- * Secondary CPUs do not run through cyc2ns_init(), so set up
+ * Secondary CPUs do not run through tsc_init(), so set up
  * all the scale factors for all CPUs, assuming the same
  * speed as the bootup CPU. (cpufreq notifiers will fix this
  * up if their speed diverges)
@@ -1389,7 +1389,7 @@ static bool __init determine_cpu_tsc_frequencies(bool early)
 	}
 
 	/*
-	 * Trust non-zero tsc_khz as authorative,
+	 * Trust non-zero tsc_khz as authoritative,
 	 * and use it to sanity check cpu_khz,
 	 * which will be off if system timer is off.
 	 */
@@ -1421,6 +1421,14 @@ static unsigned long __init get_loops_per_jiffy(void)
 	return lpj;
 }
 
+static void __init enable_use_tsc(void)
+{
+	/* Sanitize TSC ADJUST before cyc2ns gets initialized */
+	tsc_store_and_check_tsc_adjust(true);
+	cyc2ns_init_boot_cpu();
+	static_branch_enable(&__use_tsc);
+}
+
 void __init tsc_early_init(void)
 {
 	if (!boot_cpu_has(X86_FEATURE_TSC))
@@ -1429,10 +1437,7 @@ void __init tsc_early_init(void)
 		return;
 	loops_per_jiffy = get_loops_per_jiffy();
 
-	/* Sanitize TSC ADJUST before cyc2ns gets initialized */
-	tsc_store_and_check_tsc_adjust(true);
-	cyc2ns_init_boot_cpu();
-	static_branch_enable(&__use_tsc);
+	enable_use_tsc();
 }
 
 void __init tsc_init(void)
@@ -1456,13 +1461,10 @@ void __init tsc_init(void)
 			setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
 			return;
 		}
-		/* Sanitize TSC ADJUST before cyc2ns gets initialized */
-		tsc_store_and_check_tsc_adjust(true);
-		cyc2ns_init_boot_cpu();
+		enable_use_tsc();
 	}
 
 	cyc2ns_init_secondary_cpus();
-	static_branch_enable(&__use_tsc);
 
 	if (!no_sched_irq_time)
 		enable_sched_clock_irqtime();
-- 
2.14.3

Re: [PATCH 1/2] x86/tsc: Avoid a double call if TSC initializes earlier.

[Peter Zijlstra]

On Mon, Jul 30, 2018 at 03:54:20PM +0800, Dou Liyang wrote:
> static_branch_enable(&__use_tsc) may be called twice in common case, that
> is redundant.

It is also really not a problem...

Re: [PATCH 1/2] x86/tsc: Avoid a double call if TSC initializes earlier.

[Dou Liyang]

Hi Peter,

At 07/30/2018 05:34 PM, Peter Zijlstra wrote:
> On Mon, Jul 30, 2018 at 03:54:20PM +0800, Dou Liyang wrote:
>> static_branch_enable(&__use_tsc) may be called twice in common case, that
>> is redundant.
> 
> It is also really not a problem...
> 

Yes, right. Just avoid the second useless setting.

Thanks,
	dou

> 
> 

Re: [PATCH 1/2] x86/tsc: Avoid a double call if TSC initializes earlier.

[Pavel Tatashin]

On Mon, Jul 30, 2018 at 3:55 AM Dou Liyang <douly.fnst@cn.fujitsu.com> wrote:
>
> static_branch_enable(&__use_tsc) may be called twice in common case, that
> is redundant. And there are also some common functions both in
> tsc_early_init() and tsc_init().
>
> Move them into a separate helper function, only call it once.
> Also fix comments:
>  -s/authorative/authoritative
>  -s/cyc2ns_init/tsc_init
>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
> Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>

Hi Dou,

Nice cleanup.
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>

Thank you,
Pavel

> ---
>  arch/x86/kernel/tsc.c | 22 ++++++++++++----------
>  1 file changed, 12 insertions(+), 10 deletions(-)
>
> diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
> index 02e416b87ac1..ba0a6b6e0726 100644
> --- a/arch/x86/kernel/tsc.c
> +++ b/arch/x86/kernel/tsc.c
> @@ -182,7 +182,7 @@ static void __init cyc2ns_init_boot_cpu(void)
>  }
>
>  /*
> - * Secondary CPUs do not run through cyc2ns_init(), so set up
> + * Secondary CPUs do not run through tsc_init(), so set up
>   * all the scale factors for all CPUs, assuming the same
>   * speed as the bootup CPU. (cpufreq notifiers will fix this
>   * up if their speed diverges)
> @@ -1389,7 +1389,7 @@ static bool __init determine_cpu_tsc_frequencies(bool early)
>         }
>
>         /*
> -        * Trust non-zero tsc_khz as authorative,
> +        * Trust non-zero tsc_khz as authoritative,
>          * and use it to sanity check cpu_khz,
>          * which will be off if system timer is off.
>          */
> @@ -1421,6 +1421,14 @@ static unsigned long __init get_loops_per_jiffy(void)
>         return lpj;
>  }
>
> +static void __init enable_use_tsc(void)
> +{
> +       /* Sanitize TSC ADJUST before cyc2ns gets initialized */
> +       tsc_store_and_check_tsc_adjust(true);
> +       cyc2ns_init_boot_cpu();
> +       static_branch_enable(&__use_tsc);
> +}
> +
>  void __init tsc_early_init(void)
>  {
>         if (!boot_cpu_has(X86_FEATURE_TSC))
> @@ -1429,10 +1437,7 @@ void __init tsc_early_init(void)
>                 return;
>         loops_per_jiffy = get_loops_per_jiffy();
>
> -       /* Sanitize TSC ADJUST before cyc2ns gets initialized */
> -       tsc_store_and_check_tsc_adjust(true);
> -       cyc2ns_init_boot_cpu();
> -       static_branch_enable(&__use_tsc);
> +       enable_use_tsc();
>  }
>
>  void __init tsc_init(void)
> @@ -1456,13 +1461,10 @@ void __init tsc_init(void)
>                         setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
>                         return;
>                 }
> -               /* Sanitize TSC ADJUST before cyc2ns gets initialized */
> -               tsc_store_and_check_tsc_adjust(true);
> -               cyc2ns_init_boot_cpu();
> +               enable_use_tsc();
>         }
>
>         cyc2ns_init_secondary_cpus();
> -       static_branch_enable(&__use_tsc);
>
>         if (!no_sched_irq_time)
>                 enable_sched_clock_irqtime();
> --
> 2.14.3
>
>
>

[tip:x86/timers] x86/tsc: Consolidate init code

[tip-bot for Dou Liyang]

Commit-ID:  608008a45798fe9e2aee04f99b5270ea57c1376f
Gitweb:     https://git.kernel.org/tip/608008a45798fe9e2aee04f99b5270ea57c1376f
Author:     Dou Liyang <douly.fnst@cn.fujitsu.com>
AuthorDate: Mon, 30 Jul 2018 15:54:20 +0800
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Mon, 30 Jul 2018 19:33:35 +0200

x86/tsc: Consolidate init code

Split out suplicated code from tsc_early_init() and tsc_init() into a
common helper and fixup some comment typos.

[ tglx: Massaged changelog and renamed function ]

Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/20180730075421.22830-2-douly.fnst@cn.fujitsu.com

---
 arch/x86/kernel/tsc.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 02e416b87ac1..1463468ba9a0 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -182,7 +182,7 @@ static void __init cyc2ns_init_boot_cpu(void)
 }
 
 /*
- * Secondary CPUs do not run through cyc2ns_init(), so set up
+ * Secondary CPUs do not run through tsc_init(), so set up
  * all the scale factors for all CPUs, assuming the same
  * speed as the bootup CPU. (cpufreq notifiers will fix this
  * up if their speed diverges)
@@ -1389,7 +1389,7 @@ static bool __init determine_cpu_tsc_frequencies(bool early)
 	}
 
 	/*
-	 * Trust non-zero tsc_khz as authorative,
+	 * Trust non-zero tsc_khz as authoritative,
 	 * and use it to sanity check cpu_khz,
 	 * which will be off if system timer is off.
 	 */
@@ -1421,6 +1421,14 @@ static unsigned long __init get_loops_per_jiffy(void)
 	return lpj;
 }
 
+static void __init tsc_enable_sched_clock(void)
+{
+	/* Sanitize TSC ADJUST before cyc2ns gets initialized */
+	tsc_store_and_check_tsc_adjust(true);
+	cyc2ns_init_boot_cpu();
+	static_branch_enable(&__use_tsc);
+}
+
 void __init tsc_early_init(void)
 {
 	if (!boot_cpu_has(X86_FEATURE_TSC))
@@ -1429,10 +1437,7 @@ void __init tsc_early_init(void)
 		return;
 	loops_per_jiffy = get_loops_per_jiffy();
 
-	/* Sanitize TSC ADJUST before cyc2ns gets initialized */
-	tsc_store_and_check_tsc_adjust(true);
-	cyc2ns_init_boot_cpu();
-	static_branch_enable(&__use_tsc);
+	tsc_enable_sched_clock();
 }
 
 void __init tsc_init(void)
@@ -1456,13 +1461,10 @@ void __init tsc_init(void)
 			setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
 			return;
 		}
-		/* Sanitize TSC ADJUST before cyc2ns gets initialized */
-		tsc_store_and_check_tsc_adjust(true);
-		cyc2ns_init_boot_cpu();
+		tsc_enable_sched_clock();
 	}
 
 	cyc2ns_init_secondary_cpus();
-	static_branch_enable(&__use_tsc);
 
 	if (!no_sched_irq_time)
 		enable_sched_clock_irqtime();

[PATCH 2/2] x86/kvmclock: Mark kvm_get_preset_lpj() as __init

[Dou Liyang]

kvm_get_preset_lpj() just be called at kvmclock_init(), So mark it
 __init as well.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: kvm@vger.kernel.org
Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
---
 arch/x86/kernel/kvmclock.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index 91b94c0ae4e3..d2edd7e6c294 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -145,7 +145,7 @@ static unsigned long kvm_get_tsc_khz(void)
 	return pvclock_tsc_khz(this_cpu_pvti());
 }
 
-static void kvm_get_preset_lpj(void)
+static void __init kvm_get_preset_lpj(void)
 {
 	unsigned long khz;
 	u64 lpj;
-- 
2.14.3

Re: [PATCH 2/2] x86/kvmclock: Mark kvm_get_preset_lpj() as __init

[Pavel Tatashin]

On Mon, Jul 30, 2018 at 3:55 AM Dou Liyang <douly.fnst@cn.fujitsu.com> wrote:
>
> kvm_get_preset_lpj() just be called at kvmclock_init(), So mark it
>  __init as well.

Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>

Thank you,
Pavel

[tip:x86/timers] x86/kvmclock: Mark kvm_get_preset_lpj() as __init

[tip-bot for Dou Liyang]

Commit-ID:  1088c6eef261939bda8346ec35b513790a2111d5
Gitweb:     https://git.kernel.org/tip/1088c6eef261939bda8346ec35b513790a2111d5
Author:     Dou Liyang <douly.fnst@cn.fujitsu.com>
AuthorDate: Mon, 30 Jul 2018 15:54:21 +0800
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Mon, 30 Jul 2018 19:33:35 +0200

x86/kvmclock: Mark kvm_get_preset_lpj() as __init

kvm_get_preset_lpj() is only called from kvmclock_init(), so mark it __init
as well.

Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc:   Radim Krčmář<rkrcmar@redhat.com>
Cc:  <kvm@vger.kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: kvm@vger.kernel.org
Link: https://lkml.kernel.org/r/20180730075421.22830-3-douly.fnst@cn.fujitsu.com

---
 arch/x86/kernel/kvmclock.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index 91b94c0ae4e3..d2edd7e6c294 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -145,7 +145,7 @@ static unsigned long kvm_get_tsc_khz(void)
 	return pvclock_tsc_khz(this_cpu_pvti());
 }
 
-static void kvm_get_preset_lpj(void)
+static void __init kvm_get_preset_lpj(void)
 {
 	unsigned long khz;
 	u64 lpj;