xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

KVM: Introduce kvm_unmap_hva_range() for kvm_mmu_notifier_invalidate_range_start()

Browse Source 
When we tested KVM under memory pressure, with THP enabled on the host,
we noticed that MMU notifier took a long time to invalidate huge pages.

Since the invalidation was done with mmu_lock held, it not only wasted
the CPU but also made the host harder to respond.

This patch mitigates this by using kvm_handle_hva_range().

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Cc: Alexander Graf <agraf@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This commit is contained in:
Takuya Yoshikawa
2012-07-02 17:56:33 +09:00
committed by Marcelo Tosatti
parent 84504ef386
commit b3ae209697
5 changed files with 16 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
virt/kvm/kvm_main.c
View File

@@ -332,8 +332,7 @@ static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
* count is also read inside the mmu_lock critical section.
*/
kvm->mmu_notifier_count++;
for (; start < end; start += PAGE_SIZE)
need_tlb_flush |= kvm_unmap_hva(kvm, start);
need_tlb_flush = kvm_unmap_hva_range(kvm, start, end);
need_tlb_flush |= kvm->tlbs_dirty;
/* we've to flush the tlb before the pages can be freed */
if (need_tlb_flush)