I tested the entire patchset because I'm very interested in fault retries with userfaultfd and the series has been stable and worked well on x86. Tested-by: Brian Geffon <bgeffon@xxxxxxxxxx> On Thu, Feb 20, 2020 at 7:54 AM Peter Xu <peterx@xxxxxxxxxx> wrote: > > [Resend v6] > > This is v6 of the series. It is majorly a rebase to 5.6-rc2, nothing > else to be expected (plus some tests after the rebase). Instead of > rewrite the cover letter I decided to use what we have for v5. > > Adding extra CCs for both Bobby Powers <bobbypowers@xxxxxxxxx> and > Brian Geffon <bgeffon@xxxxxxxxxx>. > > Online repo: https://github.com/xzpeter/linux/tree/mm-pf-signal-retry > > Any review comment is appreciated. Thanks, > > =============== v5 cover letter ================== > > This is v5 of the series. As Matthew suggested, I split the previous > patch "mm: Return faster for non-fatal signals in user mode faults" > into a few smaller ones: > > 1. One patch to introduce fatal_signal_pending(), and use it in > archs that can directly apply > > 2. A few more patches to let the rest archs to use the new helper. > With that we can have an unified entry for signal detection > > 3. One last patch to change fatal_signal_pending() to detect > userspace non-fatal signal > > Nothing should have changed in the rest patches. Because the fault > retry patches will depend on the previous ones, I decided to simply > repost all the patches. > > Here's the new patchset layout: > > Patch 1-2: cleanup, and potential bugfix of hugetlbfs on fault retry > > Patch 3-9: let page fault to respond to non-fatal signals faster > > Patch 10: remove the userfaultfd NOPAGE emulation > > Patch 11-14: allow page fault to retry more than once > > Patch 15-16: let gup code to use FAULT_FLAG_KILLABLE too > > I would really appreciate any review comments for the series, > especially for the first two patches which IMHO are even not related > to this patchset and they should either cleanup or fix things. > > Smoke tested on x86 only. > > Thanks, > > v5: > - split "mm: Return faster for non-fatal signals in user mode faults" > into a few more patches, let all archs to use an unified entry for > fast signal handling (fatal_signal_pending) > > v4: > - use lore.kernel.org for all the links in commit messages [Kirill] > - one more patch ("mm/gup: Fix __get_user_pages() on fault retry of > hugetlb") to fix hugetlb path on fault retry > - one more patch ("mm/gup: Allow to react to fatal signals") to: > - use down_read_killable() properly [Linus] > - pass in FAULT_FLAG_KILLABLE for all GUP [Linus] > - one more patch ("mm/userfaultfd: Honor FAULT_FLAG_KILLABLE in fault > path") to let handle_userfaultfd() respect FAULT_FLAG_KILLABLE. > Should have no functional change after previous two new patches. > > v3: > - check fatal signals in __get_user_page_locked() [Linus] > - add r-bs > > v2: > - resent previous version, rebase only > > =============== v1 cover letter ================== > > This series is split out of userfaultfd-wp series to only cover the > general page fault changes, since it seems to make sense itself. > > Basically it does two things: > > (a) Allows the page fault handlers to be more interactive on not > only SIGKILL, but also the rest of userspace signals (especially > for user-mode faults), and, > > (b) Allows the page fault retry (VM_FAULT_RETRY) to happen for more > than once. > > I'm keeping the CC list as in uffd-wp v5, hopefully I'm not sending > too much spams... > > And, instead of writting again the cover letter, I'm just copy-pasting > my previous link here which has more details on why we do this: > > https://patchwork.kernel.org/cover/10691991/ > > The major change from that latest version should be that we introduced > a new page fault flag FAULT_FLAG_INTERRUPTIBLE as suggested by Linus > [1] to represents that we would like the fault handler to respond to > non-fatal signals. Also, we're more careful now on when to do the > immediate return of the page fault for such signals. For example, now > we'll only check against signal_pending() for user-mode page faults > and we keep the kernel-mode page fault patch untouched for it. More > information can be found in separate patches. > > The patchset is only lightly tested on x86. > > All comments are greatly welcomed. Thanks, > > [1] https://lkml.org/lkml/2019/6/25/1382 > > Peter Xu (16): > mm/gup: Rename "nonblocking" to "locked" where proper > mm/gup: Fix __get_user_pages() on fault retry of hugetlb > mm: Introduce fault_signal_pending() > x86/mm: Use helper fault_signal_pending() > arc/mm: Use helper fault_signal_pending() > arm64/mm: Use helper fault_signal_pending() > powerpc/mm: Use helper fault_signal_pending() > sh/mm: Use helper fault_signal_pending() > mm: Return faster for non-fatal signals in user mode faults > userfaultfd: Don't retake mmap_sem to emulate NOPAGE > mm: Introduce FAULT_FLAG_DEFAULT > mm: Introduce FAULT_FLAG_INTERRUPTIBLE > mm: Allow VM_FAULT_RETRY for multiple times > mm/gup: Allow VM_FAULT_RETRY for multiple times > mm/gup: Allow to react to fatal signals > mm/userfaultfd: Honor FAULT_FLAG_KILLABLE in fault path > > arch/alpha/mm/fault.c | 6 +-- > arch/arc/mm/fault.c | 35 +++++-------- > arch/arm/mm/fault.c | 7 +-- > arch/arm64/mm/fault.c | 26 +++------ > arch/hexagon/mm/vm_fault.c | 5 +- > arch/ia64/mm/fault.c | 5 +- > arch/m68k/mm/fault.c | 7 +-- > arch/microblaze/mm/fault.c | 5 +- > arch/mips/mm/fault.c | 5 +- > arch/nds32/mm/fault.c | 5 +- > arch/nios2/mm/fault.c | 7 +-- > arch/openrisc/mm/fault.c | 5 +- > arch/parisc/mm/fault.c | 8 ++- > arch/powerpc/mm/fault.c | 20 ++----- > arch/riscv/mm/fault.c | 9 +--- > arch/s390/mm/fault.c | 10 ++-- > arch/sh/mm/fault.c | 13 +++-- > arch/sparc/mm/fault_32.c | 5 +- > arch/sparc/mm/fault_64.c | 5 +- > arch/um/kernel/trap.c | 3 +- > arch/unicore32/mm/fault.c | 8 ++- > arch/x86/mm/fault.c | 30 +++++------ > arch/xtensa/mm/fault.c | 5 +- > drivers/gpu/drm/ttm/ttm_bo_vm.c | 12 +++-- > fs/userfaultfd.c | 62 ++++++++++------------ > include/linux/mm.h | 81 ++++++++++++++++++++++++---- > include/linux/sched/signal.h | 14 +++++ > mm/filemap.c | 2 +- > mm/gup.c | 93 +++++++++++++++++++++------------ > mm/hugetlb.c | 17 +++--- > mm/internal.h | 6 +-- > 31 files changed, 281 insertions(+), 240 deletions(-) > > -- > 2.24.1 >
