2022-03-08 11:09:16

by Wanpeng Li

Subject: [PATCH] x86/kvm: Don't waste kvmclock memory if there is nopv parameter

From: Wanpeng Li <[email protected]>

When the "nopv" command line parameter is used, it should not waste
memory for kvmclock.

Signed-off-by: Wanpeng Li <[email protected]>
---
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 c5caa73..16333ba 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -239,7 +239,7 @@ static void __init kvmclock_init_mem(void)

static int __init kvm_setup_vsyscall_timeinfo(void)
{
- if (!kvm_para_available() || !kvmclock)
+ if (!kvm_para_available() || !kvmclock || nopv)
return 0;

kvmclock_init_mem();
--
2.7.4

2022-03-09 01:42:10

by Paolo Bonzini

Subject: Re: [PATCH] x86/kvm: Don't waste kvmclock memory if there is nopv parameter

On 3/8/22 09:18, Wanpeng Li wrote:
> From: Wanpeng Li <[email protected]>
>
> When the "nopv" command line parameter is used, it should not waste
> memory for kvmclock.
>
> Signed-off-by: Wanpeng Li <[email protected]>
> ---
> 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 c5caa73..16333ba 100644
> --- a/arch/x86/kernel/kvmclock.c
> +++ b/arch/x86/kernel/kvmclock.c
> @@ -239,7 +239,7 @@ static void __init kvmclock_init_mem(void)
>
> static int __init kvm_setup_vsyscall_timeinfo(void)
> {
> - if (!kvm_para_available() || !kvmclock)
> + if (!kvm_para_available() || !kvmclock || nopv)
> return 0;
>
> kvmclock_init_mem();

Perhaps instead !kvm_para_available() && nopv should clear the kvmclock
variable?

Paolo

2022-03-09 02:28:40

by Wanpeng Li

Subject: Re: [PATCH] x86/kvm: Don't waste kvmclock memory if there is nopv parameter

On Tue, 8 Mar 2022 at 20:13, Paolo Bonzini <[email protected]> wrote:
>
> On 3/8/22 09:18, Wanpeng Li wrote:
> > From: Wanpeng Li <[email protected]>
> >
> > When the "nopv" command line parameter is used, it should not waste
> > memory for kvmclock.
> >
> > Signed-off-by: Wanpeng Li <[email protected]>
> > ---
> > 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 c5caa73..16333ba 100644
> > --- a/arch/x86/kernel/kvmclock.c
> > +++ b/arch/x86/kernel/kvmclock.c
> > @@ -239,7 +239,7 @@ static void __init kvmclock_init_mem(void)
> >
> > static int __init kvm_setup_vsyscall_timeinfo(void)
> > {
> > - if (!kvm_para_available() || !kvmclock)
> > + if (!kvm_para_available() || !kvmclock || nopv)
> > return 0;
> >
> > kvmclock_init_mem();
>
> Perhaps instead !kvm_para_available() && nopv should clear the kvmclock
> variable?

Do you mean if (!kvm_para_available() && nopv) return 0? I
misunderstand why they are the same. :)

Wanpeng

2022-04-08 08:12:51

by Wanpeng Li

Subject: Re: [PATCH] x86/kvm: Don't waste kvmclock memory if there is nopv parameter

ping,
On Tue, 8 Mar 2022 at 16:19, Wanpeng Li <[email protected]> wrote:
>
> From: Wanpeng Li <[email protected]>
>
> When the "nopv" command line parameter is used, it should not waste
> memory for kvmclock.
>
> Signed-off-by: Wanpeng Li <[email protected]>
> ---
> 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 c5caa73..16333ba 100644
> --- a/arch/x86/kernel/kvmclock.c
> +++ b/arch/x86/kernel/kvmclock.c
> @@ -239,7 +239,7 @@ static void __init kvmclock_init_mem(void)
>
> static int __init kvm_setup_vsyscall_timeinfo(void)
> {
> - if (!kvm_para_available() || !kvmclock)
> + if (!kvm_para_available() || !kvmclock || nopv)
> return 0;
>
> kvmclock_init_mem();
> --
> 2.7.4
>

2022-04-09 00:40:16

by Paolo Bonzini

Subject: Re: [PATCH] x86/kvm: Don't waste kvmclock memory if there is nopv parameter

Queued, thanks.

Paolo