From fc25cace5d623ee263d9e6ec457cf18cc9831c2e Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Fri, 7 Jun 2024 14:23:52 +0200 Subject: [PATCH] fs/proc/task_mmu: indicate PM_FILE for PMD-mapped file THP [ Upstream commit 3f9f022e975d930709848a86a1c79775b0585202 ] Patch series "fs/proc: move page_mapcount() to fs/proc/internal.h". With all other page_mapcount() users in the tree gone, move page_mapcount() to fs/proc/internal.h, rename it and extend the documentation to prevent future (ab)use. ... of course, I find some issues while working on that code that I sort first ;) We'll now only end up calling page_mapcount() [now folio_precise_page_mapcount()] on pages mapped via present page table entries. Except for /proc/kpagecount, that still does questionable things, but we'll leave that legacy interface as is for now. Did a quick sanity check. Likely we would want some better selfestest for /proc/$/pagemap + smaps. I'll see if I can find some time to write some more. This patch (of 6): Looks like we never taught pagemap_pmd_range() about the existence of PMD-mapped file THPs. Seems to date back to the times when we first added support for non-anon THPs in the form of shmem THP. Link: https://lkml.kernel.org/r/20240607122357.115423-1-david@redhat.com Link: https://lkml.kernel.org/r/20240607122357.115423-2-david@redhat.com Signed-off-by: David Hildenbrand Fixes: 800d8c63b2e9 ("shmem: add huge pages support") Acked-by: Kirill A. Shutemov Reviewed-by: Lance Yang Reviewed-by: Oscar Salvador Cc: David Hildenbrand Cc: Jonathan Corbet Cc: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin --- fs/proc/task_mmu.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 9205d3dd4..0397bbb79 100755 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1568,6 +1568,8 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end, } #endif + if (page && !PageAnon(page)) + flags |= PM_FILE; if (page && !migration && page_mapcount(page) == 1) flags |= PM_MMAP_EXCLUSIVE;