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* KVM: SVM: remove needless mmap_sem acquision from nested_svm_map
@ 2009-09-08 17:47 Marcelo Tosatti
  2009-09-09  8:37 ` Alexander Graf
  2009-09-09 11:56 ` Avi Kivity
  0 siblings, 2 replies; 3+ messages in thread
From: Marcelo Tosatti @ 2009-09-08 17:47 UTC (permalink / raw)
  To: kvm; +Cc: Alexander Graf


nested_svm_map unnecessarily takes mmap_sem around gfn_to_page, since
gfn_to_page / get_user_pages are responsible for it.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Index: kvm/arch/x86/kvm/svm.c
===================================================================
--- kvm.orig/arch/x86/kvm/svm.c
+++ kvm/arch/x86/kvm/svm.c
@@ -1394,10 +1394,7 @@ static void *nested_svm_map(struct vcpu_
 {
 	struct page *page;
 
-	down_read(&current->mm->mmap_sem);
 	page = gfn_to_page(svm->vcpu.kvm, gpa >> PAGE_SHIFT);
-	up_read(&current->mm->mmap_sem);
-
 	if (is_error_page(page))
 		goto error;
 

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: KVM: SVM: remove needless mmap_sem acquision from nested_svm_map
  2009-09-08 17:47 KVM: SVM: remove needless mmap_sem acquision from nested_svm_map Marcelo Tosatti
@ 2009-09-09  8:37 ` Alexander Graf
  2009-09-09 11:56 ` Avi Kivity
  1 sibling, 0 replies; 3+ messages in thread
From: Alexander Graf @ 2009-09-09  8:37 UTC (permalink / raw)
  To: Marcelo Tosatti; +Cc: kvm


On 08.09.2009, at 19:47, Marcelo Tosatti wrote:

>
> nested_svm_map unnecessarily takes mmap_sem around gfn_to_page, since
> gfn_to_page / get_user_pages are responsible for it.

Looks good. Sorry I didn't send it out yet.

(not tested, only looked at the code)

Acked-By: Alexander Graf <agraf@suse.de>


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: KVM: SVM: remove needless mmap_sem acquision from nested_svm_map
  2009-09-08 17:47 KVM: SVM: remove needless mmap_sem acquision from nested_svm_map Marcelo Tosatti
  2009-09-09  8:37 ` Alexander Graf
@ 2009-09-09 11:56 ` Avi Kivity
  1 sibling, 0 replies; 3+ messages in thread
From: Avi Kivity @ 2009-09-09 11:56 UTC (permalink / raw)
  To: Marcelo Tosatti; +Cc: kvm, Alexander Graf

On 09/08/2009 08:47 PM, Marcelo Tosatti wrote:
> nested_svm_map unnecessarily takes mmap_sem around gfn_to_page, since
> gfn_to_page / get_user_pages are responsible for it.
>
>    

Applied, thanks.

-- 
error compiling committee.c: too many arguments to function


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2009-09-09 11:56 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2009-09-08 17:47 KVM: SVM: remove needless mmap_sem acquision from nested_svm_map Marcelo Tosatti
2009-09-09  8:37 ` Alexander Graf
2009-09-09 11:56 ` Avi Kivity

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