[PATCH v2] PC, KVM, CMA: Fix regression caused by wrong get_order() use
From: Alexey Kardashevskiy <hidden>
Date: 2014-08-14 05:03:35
Also in:
kvm, lkml
Subsystem:
kernel virtual machine for powerpc (kvm/powerpc), linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
fc95ca7284bc54953165cba76c3228bd2cdb9591 claims that there is no functional change but this is not true as it calls get_order() (which takes bytes) where it should have called ilog2() and the kernel stops on VM_BUG_ON(). This replaces get_order() with order_base_2() (round-up version of ilog2). Suggested-by: Paul Mackerras <redacted> Cc: Alexander Graf <redacted> Cc: Aneesh Kumar K.V <redacted> Cc: Joonsoo Kim <redacted> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Alexey Kardashevskiy <redacted> --- Changes: v2: * s/ilog2/order_base_2/ * removed cc: [off-list ref] as I got wrong impression that v3.16 is broken --- arch/powerpc/kvm/book3s_hv_builtin.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
index 329d7fd..b9615ba 100644
--- a/arch/powerpc/kvm/book3s_hv_builtin.c
+++ b/arch/powerpc/kvm/book3s_hv_builtin.c@@ -101,7 +101,7 @@ struct kvm_rma_info *kvm_alloc_rma() ri = kmalloc(sizeof(struct kvm_rma_info), GFP_KERNEL); if (!ri) return NULL; - page = cma_alloc(kvm_cma, kvm_rma_pages, get_order(kvm_rma_pages)); + page = cma_alloc(kvm_cma, kvm_rma_pages, order_base_2(kvm_rma_pages)); if (!page) goto err_out; atomic_set(&ri->use_count, 1);
@@ -135,12 +135,12 @@ struct page *kvm_alloc_hpt(unsigned long nr_pages) { unsigned long align_pages = HPT_ALIGN_PAGES; - VM_BUG_ON(get_order(nr_pages) < KVM_CMA_CHUNK_ORDER - PAGE_SHIFT); + VM_BUG_ON(order_base_2(nr_pages) < KVM_CMA_CHUNK_ORDER - PAGE_SHIFT); /* Old CPUs require HPT aligned on a multiple of its size */ if (!cpu_has_feature(CPU_FTR_ARCH_206)) align_pages = nr_pages; - return cma_alloc(kvm_cma, nr_pages, get_order(align_pages)); + return cma_alloc(kvm_cma, nr_pages, order_base_2(align_pages)); } EXPORT_SYMBOL_GPL(kvm_alloc_hpt);
--
2.0.0