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

2024-04-03 Thread Catalin Marinas
On Tue, Apr 02, 2024 at 03:51:37PM +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 lock_mm_and_find_vma() and check vm_flags again, the latency > time reduce 34% in

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

2024-04-03 Thread Kefeng Wang
On 2024/4/3 13:30, Suren Baghdasaryan wrote: On Tue, Apr 2, 2024 at 10:19 PM Suren Baghdasaryan wrote: On Tue, Apr 2, 2024 at 12:53 AM 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

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

2024-04-02 Thread Suren Baghdasaryan
On Tue, Apr 2, 2024 at 10:19 PM Suren Baghdasaryan wrote: > > On Tue, Apr 2, 2024 at 12:53 AM 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

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

2024-04-02 Thread Suren Baghdasaryan
On Tue, Apr 2, 2024 at 12:53 AM 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 lock_mm_and_find_vma() and check vm_flags again, the latency > time reduce 34% in lmbench

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

2024-04-02 Thread Kefeng Wang
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 lock_mm_and_find_vma() and check vm_flags again, the latency time reduce 34% in lmbench 'lat_sig -P 1 prot lat_sig'. Signed-off-by: Kefeng Wang ---