LinuxPPC-Dev Archive on lore.kernel.org

* [PATCH] KVM: PPC: BOOK3S: HV: Don't try to allocate from kernel page allocator for hash page table.
From: Aneesh Kumar K.V @ 2014-05-04 17:25 UTC (permalink / raw)
  To: agraf, benh, paulus; +Cc: linuxppc-dev, kvm, kvm-ppc, Aneesh Kumar K.V

We reserve 5% of total ram for CMA allocation and not using that can
result in us running out of numa node memory with specific
configuration. One caveat is we may not have node local hpt with pinned
vcpu configuration. But currently libvirt also pins the vcpu to cpuset
after creating hash page table.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/powerpc/kvm/book3s_64_mmu_hv.c | 23 ++++++-----------------
 1 file changed, 6 insertions(+), 17 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index fb25ebc0af0c..f32896ffd784 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -52,7 +52,7 @@ static void kvmppc_rmap_reset(struct kvm *kvm);
 
 long kvmppc_alloc_hpt(struct kvm *kvm, u32 *htab_orderp)
 {
-	unsigned long hpt;
+	unsigned long hpt = 0;
 	struct revmap_entry *rev;
 	struct page *page = NULL;
 	long order = KVM_DEFAULT_HPT_ORDER;
@@ -64,22 +64,11 @@ long kvmppc_alloc_hpt(struct kvm *kvm, u32 *htab_orderp)
 	}
 
 	kvm->arch.hpt_cma_alloc = 0;
-	/*
-	 * try first to allocate it from the kernel page allocator.
-	 * We keep the CMA reserved for failed allocation.
-	 */
-	hpt = __get_free_pages(GFP_KERNEL | __GFP_ZERO | __GFP_REPEAT |
-			       __GFP_NOWARN, order - PAGE_SHIFT);
-
-	/* Next try to allocate from the preallocated pool */
-	if (!hpt) {
-		VM_BUG_ON(order < KVM_CMA_CHUNK_ORDER);
-		page = kvm_alloc_hpt(1 << (order - PAGE_SHIFT));
-		if (page) {
-			hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page));
-			kvm->arch.hpt_cma_alloc = 1;
-		} else
-			--order;
+	VM_BUG_ON(order < KVM_CMA_CHUNK_ORDER);
+	page = kvm_alloc_hpt(1 << (order - PAGE_SHIFT));
+	if (page) {
+		hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page));
+		kvm->arch.hpt_cma_alloc = 1;
 	}
 
 	/* Lastly try successively smaller sizes from the page allocator */
-- 
1.9.1

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