From: Matthew Wilcox <willy@infradead.org>
To: Marc Orr <marcorr@google.com>
Cc: kvm@vger.kernel.org, jmattson@google.com, rientjes@google.com,
konrad.wilk@oracle.com, linux-mm@kvack.org,
akpm@linux-foundation.org, pbonzini@redhat.com,
rkrcmar@redhat.com, sean.j.christopherson@intel.com
Subject: Re: [kvm PATCH v4 0/2] use vmalloc to allocate vmx vcpus
Date: Fri, 26 Oct 2018 05:29:48 -0700 [thread overview]
Message-ID: <20181026122948.GQ25444@bombadil.infradead.org> (raw)
In-Reply-To: <20181026075900.111462-1-marcorr@google.com>
On Fri, Oct 26, 2018 at 12:58:58AM -0700, Marc Orr wrote:
> A couple of patches to allocate vmx vcpus with vmalloc instead of
> kalloc, which enables vcpu allocation to succeeed when contiguous
> physical memory is sparse.
A question that may have been asked already, but if so I didn't see it ...
does kvm_vcpu need to be so damn big? It's 22kB with the random .config
I happen to have (which gets rounded to 32kB, an order-3 allocation). If
we can knock 6kB off it (either by allocating pieces separately), it becomes
an order-2 allocation. So, biggest chunks:
struct kvm_vcpu_arch arch; /* 576 21568 */
struct kvm_mmu mmu; /* 336 400 */
struct kvm_mmu nested_mmu; /* 736 400 */
struct fpu user_fpu; /* 2176 4160 */
struct fpu guest_fpu; /* 6336 4160 */
struct kvm_cpuid_entry2 cpuid_entries[80]; /* 10580 3200 */
struct x86_emulate_ctxt emulate_ctxt; /* 13792 2656 */
struct kvm_pmu pmu; /* 17344 1520 */
struct kvm_vcpu_hv hyperv; /* 18872 1872 */
gfn_t gfns[64]; /* 20832 512 */
that's about 19kB of the 22kB right there. Can any of them be shrunk
in size or allocated separately?
next prev parent reply other threads:[~2018-10-26 12:29 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-26 7:58 [kvm PATCH v4 0/2] use vmalloc to allocate vmx vcpus Marc Orr
2018-10-26 7:58 ` [kvm PATCH v4 1/2] kvm: vmx: refactor vmx_msrs struct for vmalloc Marc Orr
2018-10-26 11:02 ` Sean Christopherson
2018-10-26 7:59 ` [kvm PATCH v4 2/2] kvm: vmx: use vmalloc() to allocate vcpus Marc Orr
2018-10-26 12:29 ` Matthew Wilcox [this message]
2018-10-26 14:45 ` [kvm PATCH v4 0/2] use vmalloc to allocate vmx vcpus Matthew Wilcox
2018-10-26 14:49 ` Dave Hansen
2018-10-31 13:06 ` Marc Orr
2018-10-29 1:58 ` Wanpeng Li
2018-10-29 16:25 ` Jim Mattson
2018-10-29 16:48 ` Matthew Wilcox
2018-10-29 18:12 ` Jim Mattson
2018-10-29 19:16 ` Marc Orr
2018-10-29 19:22 ` Marc Orr
2018-10-31 13:17 ` Marc Orr
2018-10-31 13:27 ` Matthew Wilcox
2018-10-31 13:48 ` Marc Orr
2018-10-31 14:21 ` Matthew Wilcox
2018-10-31 21:19 ` Marc Orr
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