mainline inclusion from mainline-v6.8-rc1 commit e4621e70469c3ac6e1b6914f1c42941a8a6e44d2 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I9CUEQ CVE: NA ------------------------------------------------- Use folio_prealloc() helper and convert to use a folio in do_cow_fault(), which save five compound_head() calls. Link: https://lkml.kernel.org/r/20231118023232.1409103-5-wangkefeng.wang@huawei.co... Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> (cherry picked from commit e4621e70469c3ac6e1b6914f1c42941a8a6e44d2) Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> --- mm/memory.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index 07ff01d09abf..a80af245a682 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4971,6 +4971,7 @@ static vm_fault_t do_read_fault(struct vm_fault *vmf) static vm_fault_t do_cow_fault(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; + struct folio *folio; vm_fault_t ret; ret = vmf_can_call_fault(vmf); @@ -4979,16 +4980,11 @@ static vm_fault_t do_cow_fault(struct vm_fault *vmf) if (ret) return ret; - vmf->cow_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vmf->address); - if (!vmf->cow_page) + folio = folio_prealloc(vma->vm_mm, vma, vmf->address, false); + if (!folio) return VM_FAULT_OOM; - if (mem_cgroup_charge(page_folio(vmf->cow_page), vma->vm_mm, - GFP_KERNEL)) { - put_page(vmf->cow_page); - return VM_FAULT_OOM; - } - folio_throttle_swaprate(page_folio(vmf->cow_page), GFP_KERNEL); + vmf->cow_page = &folio->page; ret = __do_fault(vmf); if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY))) @@ -4997,7 +4993,7 @@ static vm_fault_t do_cow_fault(struct vm_fault *vmf) return ret; copy_user_highpage(vmf->cow_page, vmf->page, vmf->address, vma); - __SetPageUptodate(vmf->cow_page); + __folio_mark_uptodate(folio); ret |= finish_fault(vmf); unlock_page(vmf->page); @@ -5006,7 +5002,7 @@ static vm_fault_t do_cow_fault(struct vm_fault *vmf) goto uncharge_out; return ret; uncharge_out: - put_page(vmf->cow_page); + folio_put(folio); return ret; } -- 2.27.0