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authorMatthew Wilcox (Oracle) <willy@infradead.org>2023-08-18 23:23:34 +0300
committerAndrew Morton <akpm@linux-foundation.org>2023-08-25 02:20:29 +0300
commit40d49a3c9e4a0e5cf7a6fcebc8d4d7d63d1f3f1b (patch)
tree3bd5bfde4e95a2bb85c40cf795a8418eef084760 /mm/memory.c
parent051ddcfeb1bdbae45e660c0db2468d29ca15c6c2 (diff)
downloadlinux-40d49a3c9e4a0e5cf7a6fcebc8d4d7d63d1f3f1b.tar.xz
mm: allow ->huge_fault() to be called without the mmap_lock held
Remove the checks for the VMA lock being held, allowing the page fault path to call into the filesystem instead of retrying with the mmap_lock held. This will improve scalability for DAX page faults. Also update the documentation to match (and fix some other changes that have happened recently). Link: https://lkml.kernel.org/r/20230818202335.2739663-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/memory.c')
-rw-r--r--mm/memory.c22
1 files changed, 2 insertions, 20 deletions
diff --git a/mm/memory.c b/mm/memory.c
index 50f44c1bfa19..7a7e58729510 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4854,13 +4854,8 @@ static inline vm_fault_t create_huge_pmd(struct vm_fault *vmf)
struct vm_area_struct *vma = vmf->vma;
if (vma_is_anonymous(vma))
return do_huge_pmd_anonymous_page(vmf);
- if (vma->vm_ops->huge_fault) {
- if (vmf->flags & FAULT_FLAG_VMA_LOCK) {
- vma_end_read(vma);
- return VM_FAULT_RETRY;
- }
+ if (vma->vm_ops->huge_fault)
return vma->vm_ops->huge_fault(vmf, PE_SIZE_PMD);
- }
return VM_FAULT_FALLBACK;
}
@@ -4880,10 +4875,6 @@ static inline vm_fault_t wp_huge_pmd(struct vm_fault *vmf)
if (vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) {
if (vma->vm_ops->huge_fault) {
- if (vmf->flags & FAULT_FLAG_VMA_LOCK) {
- vma_end_read(vma);
- return VM_FAULT_RETRY;
- }
ret = vma->vm_ops->huge_fault(vmf, PE_SIZE_PMD);
if (!(ret & VM_FAULT_FALLBACK))
return ret;
@@ -4904,13 +4895,8 @@ static vm_fault_t create_huge_pud(struct vm_fault *vmf)
/* No support for anonymous transparent PUD pages yet */
if (vma_is_anonymous(vma))
return VM_FAULT_FALLBACK;
- if (vma->vm_ops->huge_fault) {
- if (vmf->flags & FAULT_FLAG_VMA_LOCK) {
- vma_end_read(vma);
- return VM_FAULT_RETRY;
- }
+ if (vma->vm_ops->huge_fault)
return vma->vm_ops->huge_fault(vmf, PE_SIZE_PUD);
- }
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
return VM_FAULT_FALLBACK;
}
@@ -4927,10 +4913,6 @@ static vm_fault_t wp_huge_pud(struct vm_fault *vmf, pud_t orig_pud)
goto split;
if (vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) {
if (vma->vm_ops->huge_fault) {
- if (vmf->flags & FAULT_FLAG_VMA_LOCK) {
- vma_end_read(vma);
- return VM_FAULT_RETRY;
- }
ret = vma->vm_ops->huge_fault(vmf, PE_SIZE_PUD);
if (!(ret & VM_FAULT_FALLBACK))
return ret;