Commit 258ed7d0 authored by Leonardo Bras's avatar Leonardo Bras Committed by Paul Mackerras
Browse files

KVM: PPC: Reduce calls to get current->mm by storing the value locally 



Reduces the number of calls to get_current() in order to get the value of
current->mm by doing it once and storing the value, since it is not
supposed to change inside the same process).

Signed-off-by: default avatarLeonardo Bras <leonardo@linux.ibm.com>
Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
parent 1a9167a2

arch/powerpc/kvm/book3s_64_mmu_hv.c

+6 −5
Original line number Diff line number Diff line
@@ -508,6 +508,7 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, 
	struct vm_area_struct *vma;

	unsigned long rcbits;

	long mmio_update;

	struct mm_struct *mm;



	if (kvm_is_radix(kvm))

		return kvmppc_book3s_radix_page_fault(run, vcpu, ea, dsisr);
@@ -584,6 +585,7 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, 
	is_ci = false;

	pfn = 0;

	page = NULL;

	mm = current->mm;

	pte_size = PAGE_SIZE;

	writing = (dsisr & DSISR_ISSTORE) != 0;

	/* If writing != 0, then the HPTE must allow writing, if we get here */
@@ -592,8 +594,8 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, 
	npages = get_user_pages_fast(hva, 1, writing ? FOLL_WRITE : 0, pages);

	if (npages < 1) {

		/* Check if it's an I/O mapping */

		down_read(&current->mm->mmap_sem);

		vma = find_vma(current->mm, hva);

		down_read(&mm->mmap_sem);

		vma = find_vma(mm, hva);

		if (vma && vma->vm_start <= hva && hva + psize <= vma->vm_end &&

		    (vma->vm_flags & VM_PFNMAP)) {

			pfn = vma->vm_pgoff +
@@ -602,7 +604,7 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, 
			is_ci = pte_ci(__pte((pgprot_val(vma->vm_page_prot))));

			write_ok = vma->vm_flags & VM_WRITE;

		}

		up_read(&current->mm->mmap_sem);

		up_read(&mm->mmap_sem);

		if (!pfn)

			goto out_put;

	} else {
@@ -621,8 +623,7 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, 
			 * hugepage split and collapse.

			 */

			local_irq_save(flags);

			ptep = find_current_mm_pte(current->mm->pgd,

						   hva, NULL, NULL);

			ptep = find_current_mm_pte(mm->pgd, hva, NULL, NULL);

			if (ptep) {

				pte = kvmppc_read_update_linux_pte(ptep, 1);

				if (__pte_write(pte))

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