Re: [PATCH v7 3/8] mm/rmap: Split try_to_munlock from try_to_unmap
From: Jason Gunthorpe <jgg@nvidia.com>
Date: 2021-03-30 18:49:49
Also in:
dri-devel, linux-mm, lkml, nouveau
On Fri, Mar 26, 2021 at 11:08:00AM +1100, Alistair Popple wrote:
+static bool try_to_munlock_one(struct page *page, struct vm_area_struct *vma,
+ unsigned long address, void *arg)
+{Is this function name right?
+ struct page_vma_mapped_walk pvmw = {
+ .page = page,
+ .vma = vma,
+ .address = address,
+ };
+
+ /* munlock has nothing to gain from examining un-locked vmas */
+ if (!(vma->vm_flags & VM_LOCKED))
+ return true;
+
+ while (page_vma_mapped_walk(&pvmw)) {
+ /* PTE-mapped THP are never mlocked */
+ if (!PageTransCompound(page)) {
+ /*
+ * Holding pte lock, we do *not* need
+ * mmap_lock here
+ */
+ mlock_vma_page(page);Because the only action this function seems to take is to call *mlock*_vma_page()
quoted hunk ↗ jump to hunk
+ } + page_vma_mapped_walk_done(&pvmw); + + /* found a mlocked page, no point continuing munlock check */ + return false; + } + + return true; +} + /** * try_to_munlock - try to munlock a page * @page: the page to be munlocked@@ -1796,8 +1821,7 @@ bool try_to_unmap(struct page *page, enum ttu_flags flags) void try_to_munlock(struct page *page) {
But this is also called try_to_munlock ?? /** * try_to_munlock - try to munlock a page * @page: the page to be munlocked * * Called from munlock code. Checks all of the VMAs mapping the page * to make sure nobody else has this page mlocked. The page will be * returned with PG_mlocked cleared if no other vmas have it mlocked. */ So what clears PG_mlocked on this call path? Something needs attention here.. Jason