From: Nadav Amit <namit@xxxxxxxxxx> This patch-set is intended to remove unnecessary TLB flushes. It is based on feedback from v1 and several bugs I found in v1 myself. Basically, there are 3 optimizations in this patch-set: 1. Avoiding TLB flushes on change_huge_pmd() that are only needed to prevent the A/D bits from changing. 2. Use TLB batching infrastructure to batch flushes across VMAs and do better/fewer flushes. 3. Avoid TLB flushes on permission demotion. Andrea asked for the aforementioned (2) to come after (3), but this is not simple (specifically since change_prot_numa() needs the number of pages affected). There are many changes from v1 to v2 so consider the change log as partial. v1->v2: * Wrong detection of permission demotion [Andrea] * Better comments [Andrea] * Handle THP [Andrea] * Batching across VMAs [Peter Xu] * Avoid open-coding PTE analysis * Fix wrong use of the mmu_gather() Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: Peter Xu <peterx@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Cc: Yu Zhao <yuzhao@xxxxxxxxxx> Cc: Nick Piggin <npiggin@xxxxxxxxx> Cc: x86@xxxxxxxxxx Nadav Amit (5): x86: Detection of Knights Landing A/D leak mm: avoid unnecessary flush on change_huge_pmd() x86/mm: check exec permissions on fault mm/mprotect: use mmu_gather mm/mprotect: do not flush on permission promotion arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/include/asm/pgtable.h | 8 +++ arch/x86/include/asm/pgtable_types.h | 2 + arch/x86/include/asm/tlbflush.h | 80 +++++++++++++++++++++++ arch/x86/kernel/cpu/intel.c | 5 ++ arch/x86/mm/fault.c | 11 +++- fs/exec.c | 6 +- include/asm-generic/tlb.h | 14 +++++ include/linux/huge_mm.h | 5 +- include/linux/mm.h | 5 +- include/linux/pgtable.h | 5 ++ mm/huge_memory.c | 22 ++++--- mm/mprotect.c | 94 +++++++++++++++------------- mm/pgtable-generic.c | 8 +++ mm/userfaultfd.c | 6 +- 15 files changed, 215 insertions(+), 57 deletions(-) -- 2.25.1
