Hi Jesper, (dropped some addresses from Cc)
> > Jesper Juhl wrote:
> There's definately a positive size impact for the generated object code
> and we save having to do the call to memset() and the cost of a vzalloc()
> call looks more or less the same as a call to vmalloc() to me.
> > This patch is not based on kvm.git, I guess.
> >
> Nope. It was generated against mainline git as of a couple of days ago. I
> can generate a version against kvm.git if you prefer.
Sorry, I should have said more clearly.
kvm_vm_ioctl_get_dirty_log() has been changed since latest mainline kernel was released.
Furthermore, vmalloc() in it is to be removed soon, currently in kvm's next.
I have checked all vmalloc() + memset() in kvm, and there are three remaining.
See the patch below.
- I have tested on x86.
- I can test ppc later if needed, but this is so trivial that Alex will see
no problem about this, probably.
So please write your Signed-off-by and ask Avi and Marcelo to apply.
Thanks,
Takuya
===
Subject: [PATCH] KVM: replace vmalloc and memset with vzalloc
Let's use newly introduced vzalloc().
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@xxxxxxxxxxxxx>
Cc: Jesper Juhl <jj@xxxxxxxxxxxxx>
---
arch/powerpc/kvm/book3s.c | 4 +---
virt/kvm/kvm_main.c | 9 ++-------
2 files changed, 3 insertions(+), 10 deletions(-)
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index e316847..badc983 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -1307,12 +1307,10 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
int err = -ENOMEM;
unsigned long p;
- vcpu_book3s = vmalloc(sizeof(struct kvmppc_vcpu_book3s));
+ vcpu_book3s = vzalloc(sizeof(struct kvmppc_vcpu_book3s));
if (!vcpu_book3s)
goto out;
- memset(vcpu_book3s, 0, sizeof(struct kvmppc_vcpu_book3s));
-
vcpu_book3s->shadow_vcpu = (struct kvmppc_book3s_shadow_vcpu *)
kzalloc(sizeof(*vcpu_book3s->shadow_vcpu), GFP_KERNEL);
if (!vcpu_book3s->shadow_vcpu)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index dbe1d6a..bd44a81 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -606,13 +606,11 @@ int __kvm_set_memory_region(struct kvm *kvm,
/* Allocate if a slot is being created */
#ifndef CONFIG_S390
if (npages && !new.rmap) {
- new.rmap = vmalloc(npages * sizeof(*new.rmap));
+ new.rmap = vzalloc(npages * sizeof(*new.rmap));
if (!new.rmap)
goto out_free;
- memset(new.rmap, 0, npages * sizeof(*new.rmap));
-
new.user_alloc = user_alloc;
new.userspace_addr = mem->userspace_addr;
}
@@ -635,14 +633,11 @@ int __kvm_set_memory_region(struct kvm *kvm,
>> KVM_HPAGE_GFN_SHIFT(level));
lpages -= base_gfn >> KVM_HPAGE_GFN_SHIFT(level);
- new.lpage_info[i] = vmalloc(lpages * sizeof(*new.lpage_info[i]));
+ new.lpage_info[i] = vzalloc(lpages * sizeof(*new.lpage_info[i]));
if (!new.lpage_info[i])
goto out_free;
- memset(new.lpage_info[i], 0,
- lpages * sizeof(*new.lpage_info[i]));
-
if (base_gfn & (KVM_PAGES_PER_HPAGE(level) - 1))
new.lpage_info[i][0].write_count = 1;
if ((base_gfn+npages) & (KVM_PAGES_PER_HPAGE(level) - 1))
--
1.7.0.4
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