[PATCH v2 2/7] arm64: mm: accelerate pagefault when VM_FAULT_BADACCESS

[Catalin Marinas]

On Wed, Apr 03, 2024 at 04:38:00PM +0800, Kefeng Wang wrote:
> The vm_flags of vma already checked under per-VMA lock, if it is a
> bad access, directly set fault to VM_FAULT_BADACCESS and handle error,
> no need to retry with mmap_lock again, the latency time reduces 34% in
> 'lat_sig -P 1 prot lat_sig' from lmbench testcase.
> 
> Since the page faut is handled under per-VMA lock, count it as a vma lock
> event with VMA_LOCK_SUCCESS.
> 
> Reviewed-by: Suren Baghdasaryan <surenb at google.com>
> Signed-off-by: Kefeng Wang <wangkefeng.wang at huawei.com>

Reviewed-by: Catalin Marinas <catalin.marinas at arm.com>