Re: [PATCH 1/2] KVM: arm64: vgic: Add memcg accounting to vgic allocations

From: Marc Zyngier <maz@kernel.org>
To: Jia He <justin.he@arm.com>
Cc: James Morse <james.morse@arm.com>,
	Alexandru Elisei <alexandru.elisei@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>, Liu Shixin <liushixin2@huawei.com>,
	Eric Auger <eric.auger@redhat.com>,
	Kees Cook <keescook@chromium.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Shenming Lu <lushenming@huawei.com>,
	Sami Tolvanen <samitolvanen@google.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Xiaoming Ni <nixiaoming@huawei.com>,
	Zenghui Yu <yuzenghui@huawei.com>,
	linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] KVM: arm64: vgic: Add memcg accounting to vgic allocations
Date: Thu, 02 Sep 2021 19:03:32 +0100	[thread overview]
Message-ID: <877dfyx3bf.wl-maz@kernel.org> (raw)
In-Reply-To: <20210902002801.32618-1-justin.he@arm.com>

Jia,

Once again: please add a cover letter when you have a patch
series. It isn't rocket science, and Git will do it for you.

On Thu, 02 Sep 2021 01:28:00 +0100,
Jia He <justin.he@arm.com> wrote:
> 
> Inspired by commit 254272ce6505 ("kvm: x86: Add memcg accounting to KVM
> allocations"), it would be better to make arm64 vgic consistent with
> common kvm codes.
> 
> The memory allocations of VM scope should be charged into VM process
> cgroup, hence change GFP_KERNEL to GFP_KERNEL_ACCOUNT.
> 
> There remained a case in vgic_set_kvm_info() since this allocation is
> global, not in VM scope.
> 
> Signed-off-by: Jia He <justin.he@arm.com>
> ---
>  arch/arm64/kvm/vgic/vgic-debug.c   |  2 +-
>  arch/arm64/kvm/vgic/vgic-init.c    |  2 +-
>  arch/arm64/kvm/vgic/vgic-irqfd.c   |  2 +-
>  arch/arm64/kvm/vgic/vgic-its.c     | 14 +++++++-------
>  arch/arm64/kvm/vgic/vgic-mmio-v3.c |  2 +-
>  arch/arm64/kvm/vgic/vgic-v4.c      |  2 +-
>  6 files changed, 12 insertions(+), 12 deletions(-)
> 
> diff --git a/arch/arm64/kvm/vgic/vgic-debug.c b/arch/arm64/kvm/vgic/vgic-debug.c
> index f38c40a76251..e6a01f210df9 100644
> --- a/arch/arm64/kvm/vgic/vgic-debug.c
> +++ b/arch/arm64/kvm/vgic/vgic-debug.c
> @@ -92,7 +92,7 @@ static void *vgic_debug_start(struct seq_file *s, loff_t *pos)
>  		goto out;
>  	}
>  
> -	iter = kmalloc(sizeof(*iter), GFP_KERNEL);
> +	iter = kmalloc(sizeof(*iter), GFP_KERNEL_ACCOUNT);

This really isn't an allocation made in the context of a VM. I don't
think this hunk belongs here.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.

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