* [PATCH] KVM: PPC: Allocate vcpu struct using vmalloc
@ 2010-02-19 11:24 ` Alexander Graf
0 siblings, 0 replies; 6+ messages in thread
From: Alexander Graf @ 2010-02-19 11:24 UTC (permalink / raw)
To: kvm-ppc; +Cc: kvm list
We used to use get_free_pages to allocate our vcpu struct. Unfortunately
that call failed on me several times after my machine had a big enough
uptime, as memory became too fragmented by then.
Fortunately, we don't need it to be page aligned any more! We can just
vmalloc it and everything's great.
Signed-off-by: Alexander Graf <agraf@suse.de>
---
arch/powerpc/kvm/book3s.c | 7 +++----
1 files changed, 3 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index f842d1d..794c94b 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -1110,8 +1110,7 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
struct kvm_vcpu *vcpu;
int err;
- vcpu_book3s = (struct kvmppc_vcpu_book3s *)__get_free_pages( GFP_KERNEL | __GFP_ZERO,
- get_order(sizeof(struct kvmppc_vcpu_book3s)));
+ vcpu_book3s = vmalloc(sizeof(struct kvmppc_vcpu_book3s));
if (!vcpu_book3s) {
err = -ENOMEM;
goto out;
@@ -1149,7 +1148,7 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
return vcpu;
free_vcpu:
- free_pages((long)vcpu_book3s, get_order(sizeof(struct kvmppc_vcpu_book3s)));
+ vfree(vcpu_book3s);
out:
return ERR_PTR(err);
}
@@ -1160,7 +1159,7 @@ void kvmppc_core_vcpu_free(struct kvm_vcpu *vcpu)
__destroy_context(vcpu_book3s->context_id);
kvm_vcpu_uninit(vcpu);
- free_pages((long)vcpu_book3s, get_order(sizeof(struct kvmppc_vcpu_book3s)));
+ vfree(vcpu_book3s);
}
extern int __kvmppc_vcpu_entry(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu);
--
1.6.0.2
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH] KVM: PPC: Allocate vcpu struct using vmalloc
@ 2010-02-19 11:24 ` Alexander Graf
0 siblings, 0 replies; 6+ messages in thread
From: Alexander Graf @ 2010-02-19 11:24 UTC (permalink / raw)
To: kvm-ppc; +Cc: kvm list
We used to use get_free_pages to allocate our vcpu struct. Unfortunately
that call failed on me several times after my machine had a big enough
uptime, as memory became too fragmented by then.
Fortunately, we don't need it to be page aligned any more! We can just
vmalloc it and everything's great.
Signed-off-by: Alexander Graf <agraf@suse.de>
---
arch/powerpc/kvm/book3s.c | 7 +++----
1 files changed, 3 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index f842d1d..794c94b 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -1110,8 +1110,7 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
struct kvm_vcpu *vcpu;
int err;
- vcpu_book3s = (struct kvmppc_vcpu_book3s *)__get_free_pages( GFP_KERNEL | __GFP_ZERO,
- get_order(sizeof(struct kvmppc_vcpu_book3s)));
+ vcpu_book3s = vmalloc(sizeof(struct kvmppc_vcpu_book3s));
if (!vcpu_book3s) {
err = -ENOMEM;
goto out;
@@ -1149,7 +1148,7 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
return vcpu;
free_vcpu:
- free_pages((long)vcpu_book3s, get_order(sizeof(struct kvmppc_vcpu_book3s)));
+ vfree(vcpu_book3s);
out:
return ERR_PTR(err);
}
@@ -1160,7 +1159,7 @@ void kvmppc_core_vcpu_free(struct kvm_vcpu *vcpu)
__destroy_context(vcpu_book3s->context_id);
kvm_vcpu_uninit(vcpu);
- free_pages((long)vcpu_book3s, get_order(sizeof(struct kvmppc_vcpu_book3s)));
+ vfree(vcpu_book3s);
}
extern int __kvmppc_vcpu_entry(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu);
--
1.6.0.2
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: PPC: Allocate vcpu struct using vmalloc
[not found] ` <1266578673-32254-1-git-send-email-agraf-l3A5Bk7waGM@public.gmane.org>
@ 2010-02-21 12:29 ` Avi Kivity
0 siblings, 0 replies; 6+ messages in thread
From: Avi Kivity @ 2010-02-21 12:29 UTC (permalink / raw)
To: Alexander Graf; +Cc: kvm-ppc-u79uwXL29TY76Z2rM5mHXA, kvm list
On 02/19/2010 01:24 PM, Alexander Graf wrote:
> We used to use get_free_pages to allocate our vcpu struct. Unfortunately
> that call failed on me several times after my machine had a big enough
> uptime, as memory became too fragmented by then.
>
> Fortunately, we don't need it to be page aligned any more! We can just
> vmalloc it and everything's great.
>
Applied, thanks.
We have the same problem in x86 (though never observed it in practice);
my plan there is to split the various structure so they take less than a
page.
--
error compiling committee.c: too many arguments to function
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: PPC: Allocate vcpu struct using vmalloc
@ 2010-02-21 12:29 ` Avi Kivity
0 siblings, 0 replies; 6+ messages in thread
From: Avi Kivity @ 2010-02-21 12:29 UTC (permalink / raw)
To: Alexander Graf; +Cc: kvm-ppc-u79uwXL29TY76Z2rM5mHXA, kvm list
On 02/19/2010 01:24 PM, Alexander Graf wrote:
> We used to use get_free_pages to allocate our vcpu struct. Unfortunately
> that call failed on me several times after my machine had a big enough
> uptime, as memory became too fragmented by then.
>
> Fortunately, we don't need it to be page aligned any more! We can just
> vmalloc it and everything's great.
>
Applied, thanks.
We have the same problem in x86 (though never observed it in practice);
my plan there is to split the various structure so they take less than a
page.
--
error compiling committee.c: too many arguments to function
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: PPC: Allocate vcpu struct using vmalloc
2010-02-19 11:24 ` Alexander Graf
(?)
(?)
@ 2010-02-21 14:50 ` Alexander Graf
-1 siblings, 0 replies; 6+ messages in thread
From: Alexander Graf @ 2010-02-21 14:50 UTC (permalink / raw)
To: kvm-ppc
On 21.02.2010, at 13:29, Avi Kivity wrote:
> On 02/19/2010 01:24 PM, Alexander Graf wrote:
>> We used to use get_free_pages to allocate our vcpu struct. Unfortunately
>> that call failed on me several times after my machine had a big enough
>> uptime, as memory became too fragmented by then.
>>
>> Fortunately, we don't need it to be page aligned any more! We can just
>> vmalloc it and everything's great.
>>
>
> Applied, thanks.
>
> We have the same problem in x86 (though never observed it in practice); my plan there is to split the various structure so they take less than a page.
That was my original idea too, but then I looked over the code again and realized that I never need to access the vcpu struct from critical sections, as we moved everything we need there to the PACA.
I also did experience it several times on PPC. But then again, I'm fairly sure the Book3S vcpu struct is a _lot_ larger than the average x86 vcpu struct ;-). I'd need to actually measure it up, but I'm pretty sure it's > 64k.
Alex
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: PPC: Allocate vcpu struct using vmalloc
2010-02-19 11:24 ` Alexander Graf
` (2 preceding siblings ...)
(?)
@ 2010-02-21 15:08 ` Avi Kivity
-1 siblings, 0 replies; 6+ messages in thread
From: Avi Kivity @ 2010-02-21 15:08 UTC (permalink / raw)
To: kvm-ppc
On 02/21/2010 04:50 PM, Alexander Graf wrote:
> On 21.02.2010, at 13:29, Avi Kivity wrote:
>
>
>> On 02/19/2010 01:24 PM, Alexander Graf wrote:
>>
>>> We used to use get_free_pages to allocate our vcpu struct. Unfortunately
>>> that call failed on me several times after my machine had a big enough
>>> uptime, as memory became too fragmented by then.
>>>
>>> Fortunately, we don't need it to be page aligned any more! We can just
>>> vmalloc it and everything's great.
>>>
>>>
>> Applied, thanks.
>>
>> We have the same problem in x86 (though never observed it in practice); my plan there is to split the various structure so they take less than a page.
>>
> That was my original idea too, but then I looked over the code again and realized that I never need to access the vcpu struct from critical sections, as we moved everything we need there to the PACA.
>
> I also did experience it several times on PPC. But then again, I'm fairly sure the Book3S vcpu struct is a _lot_ larger than the average x86 vcpu struct ;-). I'd need to actually measure it up, but I'm pretty sure it's> 64k.
>
Right, x86 is around 8k, which is the thread stack size, and if we can't
allocate that we're really dead.
--
error compiling committee.c: too many arguments to function
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2010-02-21 15:08 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2010-02-19 11:24 [PATCH] KVM: PPC: Allocate vcpu struct using vmalloc Alexander Graf
2010-02-19 11:24 ` Alexander Graf
[not found] ` <1266578673-32254-1-git-send-email-agraf-l3A5Bk7waGM@public.gmane.org>
2010-02-21 12:29 ` Avi Kivity
2010-02-21 12:29 ` Avi Kivity
2010-02-21 14:50 ` Alexander Graf
2010-02-21 15:08 ` Avi Kivity
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