include/uapi/linux/restrictedmem.h | 1 + mm/restrictedmem.c | 27 ++++++++++++------- .../restrictedmem_hugepage_test.c | 25 +++++++++++++++++ 3 files changed, 43 insertions(+), 10 deletions(-)
Hello, This patchset builds upon the memfd_restricted() system call that has been discussed in the ‘KVM: mm: fd-based approach for supporting KVM’ patch series, at https://lore.kernel.org/lkml/20221202061347.1070246-1-chao.p.peng@linux.intel.com/T/#m7e944d7892afdd1d62a03a287bd488c56e377b0c The tree can be found at: https://github.com/googleprodkernel/linux-cc/tree/restrictedmem-rmfd-hugepage Following the RFC to provide mount for memfd_restricted() syscall at https://lore.kernel.org/lkml/cover.1676507663.git.ackerleytng@google.com/T/#u, this patchset adds the RMFD_HUGEPAGE flag to the memfd_restricted() syscall, which will hint the kernel to use Transparent HugePages to back restrictedmem pages. This supplements the interface proposed earlier, which requires the creation of a tmpfs mount to be passed to memfd_restricted(), with a more direct per-file hint. Dependencies: + Sean’s iteration of the ‘KVM: mm: fd-based approach for supporting KVM’ patch series at https://github.com/sean-jc/linux/tree/x86/upm_base_support + Proposed fix for restrictedmem_getattr() as mentioned on the mailing list at https://lore.kernel.org/lkml/diqzzga0fv96.fsf@ackerleytng-cloudtop-sg.c.googlers.com/ + Hugh’s patch: https://lore.kernel.org/lkml/c140f56a-1aa3-f7ae-b7d1-93da7d5a3572@google.com/, which provides functionality in shmem that reads the VM_HUGEPAGE flag in key functions shmem_is_huge() and shmem_get_inode() Future work/TODOs: + man page for the memfd_restricted() syscall + Support for per file NUMA binding hints Ackerley Tng (2): mm: restrictedmem: Add flag as THP allocation hint for memfd_restricted() syscall selftests: restrictedmem: Add selftest for RMFD_HUGEPAGE include/uapi/linux/restrictedmem.h | 1 + mm/restrictedmem.c | 27 ++++++++++++------- .../restrictedmem_hugepage_test.c | 25 +++++++++++++++++ 3 files changed, 43 insertions(+), 10 deletions(-) -- 2.39.2.637.g21b0678d19-goog
On Sat, Feb 18, 2023 at 12:43:00AM +0000, Ackerley Tng wrote: > Hello, > > This patchset builds upon the memfd_restricted() system call that has > been discussed in the ‘KVM: mm: fd-based approach for supporting KVM’ > patch series, at > https://lore.kernel.org/lkml/20221202061347.1070246-1-chao.p.peng@linux.intel.com/T/#m7e944d7892afdd1d62a03a287bd488c56e377b0c > > The tree can be found at: > https://github.com/googleprodkernel/linux-cc/tree/restrictedmem-rmfd-hugepage > > Following the RFC to provide mount for memfd_restricted() syscall at > https://lore.kernel.org/lkml/cover.1676507663.git.ackerleytng@google.com/T/#u, > this patchset adds the RMFD_HUGEPAGE flag to the memfd_restricted() > syscall, which will hint the kernel to use Transparent HugePages to > back restrictedmem pages. > > This supplements the interface proposed earlier, which requires the > creation of a tmpfs mount to be passed to memfd_restricted(), with a > more direct per-file hint. > > Dependencies: > > + Sean’s iteration of the ‘KVM: mm: fd-based approach for supporting > KVM’ patch series at > https://github.com/sean-jc/linux/tree/x86/upm_base_support > + Proposed fix for restrictedmem_getattr() as mentioned on the mailing > list at > https://lore.kernel.org/lkml/diqzzga0fv96.fsf@ackerleytng-cloudtop-sg.c.googlers.com/ > + Hugh’s patch: > https://lore.kernel.org/lkml/c140f56a-1aa3-f7ae-b7d1-93da7d5a3572@google.com/, > which provides functionality in shmem that reads the VM_HUGEPAGE > flag in key functions shmem_is_huge() and shmem_get_inode() Will Hugh's patch be merged into 6.3 ? I didn't find it in 6.2-rc8. IMHO this patch won't work without Hugh's patch, or at least need another way, e.g. HMEM_SB(inode->i_sb)->huge. > > Future work/TODOs: > + man page for the memfd_restricted() syscall > + Support for per file NUMA binding hints > > Ackerley Tng (2): > mm: restrictedmem: Add flag as THP allocation hint for > memfd_restricted() syscall > selftests: restrictedmem: Add selftest for RMFD_HUGEPAGE > > include/uapi/linux/restrictedmem.h | 1 + > mm/restrictedmem.c | 27 ++++++++++++------- > .../restrictedmem_hugepage_test.c | 25 +++++++++++++++++ > 3 files changed, 43 insertions(+), 10 deletions(-) > > -- > 2.39.2.637.g21b0678d19-goog >
Yuan Yao <yuan.yao@linux.intel.com> writes: > On Sat, Feb 18, 2023 at 12:43:00AM +0000, Ackerley Tng wrote: >> Hello, >> This patchset builds upon the memfd_restricted() system call that has >> been discussed in the ‘KVM: mm: fd-based approach for supporting KVM’ >> patch series, at >> https://lore.kernel.org/lkml/20221202061347.1070246-1-chao.p.peng@linux.intel.com/T/#m7e944d7892afdd1d62a03a287bd488c56e377b0c >> The tree can be found at: >> https://github.com/googleprodkernel/linux-cc/tree/restrictedmem-rmfd-hugepage >> Following the RFC to provide mount for memfd_restricted() syscall at >> https://lore.kernel.org/lkml/cover.1676507663.git.ackerleytng@google.com/T/#u, >> this patchset adds the RMFD_HUGEPAGE flag to the memfd_restricted() >> syscall, which will hint the kernel to use Transparent HugePages to >> back restrictedmem pages. >> This supplements the interface proposed earlier, which requires the >> creation of a tmpfs mount to be passed to memfd_restricted(), with a >> more direct per-file hint. >> Dependencies: >> + Sean’s iteration of the ‘KVM: mm: fd-based approach for supporting >> KVM’ patch series at >> https://github.com/sean-jc/linux/tree/x86/upm_base_support >> + Proposed fix for restrictedmem_getattr() as mentioned on the mailing >> list at >> >> https://lore.kernel.org/lkml/diqzzga0fv96.fsf@ackerleytng-cloudtop-sg.c.googlers.com/ >> + Hugh’s patch: >> >> https://lore.kernel.org/lkml/c140f56a-1aa3-f7ae-b7d1-93da7d5a3572@google.com/, >> which provides functionality in shmem that reads the VM_HUGEPAGE >> flag in key functions shmem_is_huge() and shmem_get_inode() > Will Hugh's patch be merged into 6.3 ? I didn't find it in 6.2-rc8. > IMHO this patch won't work without Hugh's patch, or at least need > another way, e.g. HMEM_SB(inode->i_sb)->huge. Hugh's patch is still pending discussion and may not be merged so soon. These patches will not work without Hugh's patch. I would like to understand what the community thinks of the proposed interface (RMFD_HUGEPAGE flag, passed to the memfd_restricted() syscall). If this interface is favorably received, we can definitely find another way for shmem to support this interface. If I understand correctly, SHMEM_SB(inode->i_sb)->huge checks the state of hugepage-ness for the superblock. Since the proposed interface will only affect a single file, we will need something closer to bool shmem_is_huge(struct vm_area_struct *vma, struct inode *inode, pgoff_t index, bool shmem_huge_force) { ... if (SHMEM_I(inode)->flags & VM_HUGEPAGE) return true; ... } from Hugh's patch.
© 2016 - 2024 Red Hat, Inc.