Recently, I got a report get_user_pages_fast helps app's launching time due to reducing uninterruptible sleep time because it could reduce mmap_sem lock contentions when app is launching.
To support gupf in ARM-non-LPAE, first patch reorders memory type table to use 5th bit of the page table. Second patch introduces L_PTE_SPECIAL for arm so that last patch can support get_user_pags_fast. I would greatly appreciate if guys review that I screw up something, especially, architecture stuffs. * from RFC * Remove CPU_v7M - Catalin * define DEV_NONSHARED to SHARED - Catalin * https://lkml.kernel.org/r/20180910165011.zcighyuabshsm...@armageddon.cambridge.arm.com Minchan Kim (3): arm: mm: reordering memory type table arm: mm: introduce L_PTE_SPECIAL arm: mm: support get_user_pages_fast arch/arm/Kconfig | 2 +- arch/arm/include/asm/pgtable-2level.h | 22 ++- arch/arm/include/asm/pgtable-3level.h | 6 - arch/arm/include/asm/pgtable.h | 13 ++ arch/arm/mm/Makefile | 6 + arch/arm/mm/gup.c | 221 ++++++++++++++++++++++++++ arch/arm/mm/proc-macros.S | 4 +- 7 files changed, 259 insertions(+), 15 deletions(-) create mode 100644 arch/arm/mm/gup.c -- 2.19.0.397.gdd90340f6a-goog
