linux-stable/virt
Paolo Bonzini b9b33da2aa KVM: try __get_user_pages_fast even if not in atomic context
We are currently cutting hva_to_pfn_fast short if we do not want an
immediate exit, which is represented by !async && !atomic.  However,
this is unnecessary, and __get_user_pages_fast is *much* faster
because the regular get_user_pages takes pmd_lock/pte_lock.
In fact, when many CPUs take a nested vmexit at the same time
the contention on those locks is visible, and this patch removes
about 25% (compared to 4.18) from vmexit.flat on a 16 vCPU
nested guest.

Suggested-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-08-06 17:59:07 +02:00
..
kvm KVM: try __get_user_pages_fast even if not in atomic context 2018-08-06 17:59:07 +02:00
lib KVM: eventfd: fix NULL deref irqbypass consumer 2017-01-12 14:42:34 +01:00
Makefile virt: Add virt directory to the top Makefile 2015-10-01 15:06:44 +02:00