IF YOU WOULD LIKE TO GET AN ACCOUNT, please write an
email to Administrator. User accounts are meant only to access repo
and report issues and/or generate pull requests.
This is a purpose-specific Git hosting for
BaseALT
projects. Thank you for your understanding!
Только зарегистрированные пользователи имеют доступ к сервису!
Для получения аккаунта, обратитесь к администратору.
When retpolines are enabled they have high overhead in the inner loop
inside kvm_handle_hva_range() that iterates over the provided memory area.
Let's mark this function and its TDP MMU equivalent __always_inline so
compiler will be able to change the call to the actual handler function
inside each of them into a direct one.
This significantly improves performance on the unmap test on the existing
kernel memslot code (tested on a Xeon 8167M machine):
30 slots in use:
Test Before After Improvement
Unmap 0.0353s 0.0334s 5%
Unmap 2M 0.00104s 0.000407s 61%
509 slots in use:
Test Before After Improvement
Unmap 0.0742s 0.0740s None
Unmap 2M 0.00221s 0.00159s 28%
Looks like having an indirect call in these functions (and, so, a
retpoline) might have interfered with unrolling of the whole loop in the
CPU.
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <732d3fe9eb68aa08402a638ab0309199fa89ae56.1612810129.git.maciej.szmigiero@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
8f5c44f953