Messages in this thread | | | Date | Wed, 17 Dec 2014 09:38:57 +0800 | From | "Chen, Tiejun" <> | Subject | Re: [PATCH] kvm: iommu: Add cond_resched to legacy device assignment code |
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On 2014/12/16 23:47, Joerg Roedel wrote: > From: Joerg Roedel <jroedel@suse.de> > > When assigning devices to large memory guests (>=128GB guest > memory in the failure case) the functions to create the > IOMMU page-tables for the whole guest might run for a very > long time. On non-preemptible kernels this might cause > Soft-Lockup warnings. Fix these by adding a cond_resched() > to the mapping and unmapping loops. > > Signed-off-by: Joerg Roedel <jroedel@suse.de> > --- > virt/kvm/iommu.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c > index c1e6ae9..ac427e8 100644 > --- a/virt/kvm/iommu.c > +++ b/virt/kvm/iommu.c
This file is already gone after one latest commit c274e03af705, "kvm: x86: move assigned-dev.c and iommu.c to arch/x86/" is introduced, so you need to pull your tree firstly :)
Tiejun
> @@ -137,7 +137,7 @@ int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot) > > gfn += page_size >> PAGE_SHIFT; > > - > + cond_resched(); > } > > return 0; > @@ -311,6 +311,8 @@ static void kvm_iommu_put_pages(struct kvm *kvm, > kvm_unpin_pages(kvm, pfn, unmap_pages); > > gfn += unmap_pages; > + > + cond_resched(); > } > } > >
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