renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-15 08:44:14 +08:00
Code

s390/mm: remove useless hugepage address alignment

Browse Source 
The failing address alignment to HPAGE_MASK in do_exception(), for
hugetlb faults, was useless from the beginning. With 2 GB hugepage
support it became wrong, but w/o further negative impact. Now it
could have negative performance impact because it breaks the cacheline
optimization for process_huge_page().

Therefore, remove it.

Note that we still have failing address alignment by HW to PAGE_SIZE,
for all page faults, not just hugetlb faults. So this patch will not
fix UFFD_FEATURE_EXACT_ADDRESS for userfaultfd handling. It will just
move the failing address for hugetlb faults a bit closer to the real
address, at 4K page granularity, similar to normal page faults.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This commit is contained in:
Gerald Schaefer 2022-08-19 19:40:11 +02:00 committed by Vasily Gorbik
parent b90cb10531
commit ff03b88467
1 changed files with 0 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/s390/mm/fault.c
View File

@ -421,8 +421,6 @@ retry:
if (unlikely(!(vma->vm_flags & access))) if (unlikely(!(vma->vm_flags & access)))
goto out_up; goto out_up;
if (is_vm_hugetlb_page(vma))
address &= HPAGE_MASK;
/* /*
* If for any reason at all we couldn't handle the fault, * If for any reason at all we couldn't handle the fault,
* make sure we exit gracefully rather than endlessly redo * make sure we exit gracefully rather than endlessly redo