| Message ID | 20231212073803.3233055-1-vivek.kasireddy@intel.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | mm/gup: Introduce memfd_pin_folios() for pinning memfd folios (v7) | expand |
On 12.12.23 08:37, Vivek Kasireddy wrote: > The first two patches were previously reviewed but not yet merged. > These ones need to be merged first as the fourth patch depends on > the changes introduced in them and they also fix bugs seen in > very specific scenarios (running Qemu with hugetlb=on, blob=true > and rebooting guest VM). > > The third patch introduces memfd_pin_folios() API and the fourth > patch converts udmabuf driver to use folios. The fifth patch shows > how the udmabuf driver can make use of the new API to longterm-pin > the folios. The last patch adds two new udmabuf selftests to verify > data coherency after potential page migration. > We should probably get started with the first two patches, they are independent of the remaining discussion regarding memfd_pin_folios().
The first two patches were previously reviewed but not yet merged. These ones need to be merged first as the fourth patch depends on the changes introduced in them and they also fix bugs seen in very specific scenarios (running Qemu with hugetlb=on, blob=true and rebooting guest VM). The third patch introduces memfd_pin_folios() API and the fourth patch converts udmabuf driver to use folios. The fifth patch shows how the udmabuf driver can make use of the new API to longterm-pin the folios. The last patch adds two new udmabuf selftests to verify data coherency after potential page migration. v2: - Updated the first patch to include review feedback from David and Jason. The main change in this series is the allocation of page in the case of hugetlbfs if it is not found in the page cache. v3: - Made changes to include review feedback from David to improve the comments and readability of code - Enclosed the hugepage alloc code with #ifdef CONFIG_HUGETLB_PAGE v4: - Augmented the commit message of the udmabuf patch that uses pin_user_pages_fd() - Added previously reviewed but unmerged udmabuf patches to this series v5: - Updated the patch that adds pin_user_pages_fd() to include feedback from David to handle simultaneous users trying to add a huge page to the mapping - Replaced find_get_page_flags() with __filemap_get_folio() in the second and third patches to ensure that we only obtain head pages from the mapping v6: (Christoph) - Renamed the new API to memfd_pin_user_pages() - Improved the page cache lookup efficiency by using filemap_get_folios_contig() which uses batches v7: - Rename the new API to memfd_pin_folios() and make it return folios and offsets (David) - Added a new preparatory patch to this series to convert udmabuf driver to use folios This series is tested using following methods: - Run the subtests added in the fifth patch - Run Qemu (master) with the following options and a few additional patches to Spice: qemu-system-x86_64 -m 4096m.... -device virtio-gpu-pci,max_outputs=1,blob=true,xres=1920,yres=1080 -spice port=3001,gl=on,disable-ticketing=on,preferred-codec=gstreamer:h264 -object memory-backend-memfd,hugetlb=on,id=mem1,size=4096M -machine memory-backend=mem1 Cc: David Hildenbrand <david@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Gerd Hoffmann <kraxel@redhat.com> Cc: Dongwon Kim <dongwon.kim@intel.com> Cc: Junxiao Chang <junxiao.chang@intel.com> Vivek Kasireddy (6): udmabuf: Use vmf_insert_pfn and VM_PFNMAP for handling mmap udmabuf: Add back support for mapping hugetlb pages (v6) mm/gup: Introduce memfd_pin_folios() for pinning memfd folios (v7) udmabuf: Convert udmabuf driver to use folios udmabuf: Pin the pages using memfd_pin_folios() API (v5) selftests/dma-buf/udmabuf: Add tests to verify data after page migration drivers/dma-buf/udmabuf.c | 166 +++++++++++------- include/linux/memfd.h | 5 + include/linux/mm.h | 3 + mm/gup.c | 155 ++++++++++++++++ mm/memfd.c | 34 ++++ .../selftests/drivers/dma-buf/udmabuf.c | 151 +++++++++++++++- 6 files changed, 451 insertions(+), 63 deletions(-)