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authorChristian Borntraeger <borntraeger@de.ibm.com>2014-03-19 11:18:29 +0100
committerChristian Borntraeger <borntraeger@de.ibm.com>2014-03-25 13:27:10 +0100
commitf6c137ff00a478ae619deea8650829dd2f8e71b9 (patch)
tree6bdaf9f3273aba64328345918fa42900f0054282 /arch/s390/kvm
parent94b3ffcd41a90d2cb0b32ca23aa58a01111d5dc0 (diff)
KVM: s390: randomize sca address
We allocate a page for the 2k sca, so lets use the space to improve hit rate of some internal cpu caches. No need to change the freeing of the page, as this will shift away the page offset bits anyway. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Diffstat (limited to 'arch/s390/kvm')
-rw-r--r--arch/s390/kvm/kvm-s390.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 7337c577e949..a02979f1e1af 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -215,6 +215,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
{
int rc;
char debug_name[16];
+ static unsigned long sca_offset;
rc = -EINVAL;
#ifdef CONFIG_KVM_S390_UCONTROL
@@ -236,6 +237,10 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
kvm->arch.sca = (struct sca_block *) get_zeroed_page(GFP_KERNEL);
if (!kvm->arch.sca)
goto out_err;
+ spin_lock(&kvm_lock);
+ sca_offset = (sca_offset + 16) & 0x7f0;
+ kvm->arch.sca = (struct sca_block *) ((char *) kvm->arch.sca + sca_offset);
+ spin_unlock(&kvm_lock);
sprintf(debug_name, "kvm-%u", current->pid);