[PATCH v2 0/7] arch/mm/fault: accelerate pagefault when badaccess

[Kefeng Wang]

On 2024/4/4 4:45, Andrew Morton wrote:
> On Wed, 3 Apr 2024 16:37:58 +0800 Kefeng Wang <wangkefeng.wang at huawei.com> wrote:
> 
>> After VMA lock-based page fault handling enabled, if bad access met
>> under per-vma lock, it will fallback to mmap_lock-based handling,
>> so it leads to unnessary mmap lock and vma find again. A test from
>> lmbench shows 34% improve after this changes on arm64,
>>
>>    lat_sig -P 1 prot lat_sig 0.29194 -> 0.19198
>>
>> Only build test on other archs except arm64.
> 
> Thanks.  So we now want a bunch of architectures to runtime test this.  Do
> we have a selftest in place which will adequately do this?

I don't find such selftest, and badaccess would lead to coredump, the
performance should not affect most scene, so no selftest is acceptable.
lmbench is easy to use to measure the performance.