Re: [PATCH] KVM x86: remove memset, use vzalloc and don't assignthe same value to a variable twice

From: Jesper Juhl
Date: Tue Nov 02 2010 - 00:22:13 EST


On Tue, 2 Nov 2010, Takuya Yoshikawa wrote:

> 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>

Signed-off-by: Jesper-juhl <jj@xxxxxxxxxxxxx>


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