From 072c35fb69e238b377bddea576a405ab8ecddf9a Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Mon, 24 Jul 2023 19:54:07 +0100 Subject: [PATCH] FROMGIT: mm: move FAULT_FLAG_VMA_LOCK check down from do_fault() Perform the check at the start of do_read_fault(), do_cow_fault() and do_shared_fault() instead. Should be no performance change from the last commit. Link: https://lkml.kernel.org/r/20230724185410.1124082-8-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Suren Baghdasaryan Cc: Arjun Roy Cc: Eric Dumazet Cc: Punit Agrawal Signed-off-by: Andrew Morton (cherry picked from commit 4e105ec567c874c166a8e5a9b2dd849c8ec2055e https: //git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-unstable) Bug: 293665307 Change-Id: I37be370a0378afd094d880bb8e538e4e7874499e Signed-off-by: Suren Baghdasaryan --- mm/memory.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index e3a683bd9e70..de01fb70f5f0 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4585,6 +4585,11 @@ static vm_fault_t do_read_fault(struct vm_fault *vmf) { vm_fault_t ret = 0; + if (vmf->flags & FAULT_FLAG_VMA_LOCK) { + vma_end_read(vmf->vma); + return VM_FAULT_RETRY; + } + /* * Let's call ->map_pages() first and use ->fault() as fallback * if page by the offset is not ready to be mapped (cold cache or @@ -4612,6 +4617,11 @@ static vm_fault_t do_cow_fault(struct vm_fault *vmf) struct vm_area_struct *vma = vmf->vma; vm_fault_t ret; + if (vmf->flags & FAULT_FLAG_VMA_LOCK) { + vma_end_read(vma); + return VM_FAULT_RETRY; + } + if (unlikely(anon_vma_prepare(vma))) return VM_FAULT_OOM; @@ -4651,6 +4661,11 @@ static vm_fault_t do_shared_fault(struct vm_fault *vmf) struct vm_area_struct *vma = vmf->vma; vm_fault_t ret, tmp; + if (vmf->flags & FAULT_FLAG_VMA_LOCK) { + vma_end_read(vma); + return VM_FAULT_RETRY; + } + ret = __do_fault(vmf); if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY))) return ret; @@ -4695,11 +4710,6 @@ static vm_fault_t do_fault(struct vm_fault *vmf) struct mm_struct *vm_mm = vma->vm_mm; vm_fault_t ret; - if (vmf->flags & FAULT_FLAG_VMA_LOCK){ - vma_end_read(vma); - return VM_FAULT_RETRY; - } - /* * The VMA was not fully populated on mmap() or missing VM_DONTEXPAND */