| Message ID | 20240607122357.115423-1-david@redhat.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | fs/proc: move page_mapcount() to fs/proc/internal.h | expand |
On Fri, Jun 07, 2024 at 02:23:51PM +0200, David Hildenbrand wrote: > 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/$/pagemap + smaps. I'll see if I can find some time to write > some more. I stumbled upon some of these issues while unifying .{pud/pmd}_entry and .hugetlb_entry. I am not sure what is the current state of pagemap/smaps selftest, but since I am going to need them anyway to keep me in check and making sure I do not break anything hugetlb-related, I might as well write some of them.
With all other page_mapcount() users in the tree gone, move page_mapcount() to fs/proc/internal.h, rename it and extend the documentation to prevent future (ab)use. ... of course, I find some issues while working on that code that I sort first ;) We'll now only end up calling page_mapcount() [now folio_precise_page_mapcount()] on pages mapped via present page table entries. Except for /proc/kpagecount, that still does questionable things, but we'll leave that legacy interface as is for now. Did a quick sanity check. Likely we would want some better selfestest for /proc/$/pagemap + smaps. I'll see if I can find some time to write some more. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jonathan Corbet <corbet@lwn.net> David Hildenbrand (6): fs/proc/task_mmu: indicate PM_FILE for PMD-mapped file THP fs/proc/task_mmu: don't indicate PM_MMAP_EXCLUSIVE without PM_PRESENT fs/proc/task_mmu: properly detect PM_MMAP_EXCLUSIVE per page of PMD-mapped THPs fs/proc/task_mmu: account non-present entries as "maybe shared, but no idea how often" fs/proc: move page_mapcount() to fs/proc/internal.h Documentation/admin-guide/mm/pagemap.rst: drop "Using pagemap to do something useful" Documentation/admin-guide/mm/pagemap.rst | 21 ----- fs/proc/internal.h | 33 ++++++++ fs/proc/page.c | 21 +++-- fs/proc/task_mmu.c | 102 +++++++++++++---------- include/linux/mm.h | 27 +----- 5 files changed, 104 insertions(+), 100 deletions(-) base-commit: 19b8422c5bd56fb5e7085995801c6543a98bda1f