> On Feb 3, 2021, at 1:44 AM, Will Deacon <will@xxxxxxxxxx> wrote: > > On Tue, Feb 02, 2021 at 01:35:38PM -0800, Nadav Amit wrote: >>> On Feb 2, 2021, at 3:00 AM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: >>> >>> On Tue, Feb 02, 2021 at 01:32:36AM -0800, Nadav Amit wrote: >>>>> On Feb 1, 2021, at 3:36 AM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: >>>>> >>>>> >>>>> https://lkml.kernel.org/r/20210127235347.1402-1-will@xxxxxxxxxx >>>> >>>> I have seen this series, and applied my patches on it. >>>> >>>> Despite Will’s patches, there were still inconsistencies between fullmm >>>> and need_flush_all. >>>> >>>> Am I missing something? >>> >>> I wasn't aware you were on top. I'll look again. >> >> Looking on arm64’s tlb_flush() makes me think that there is currently a bug >> that this patch fixes. Arm64’s tlb_flush() does: >> >> /* >> * If we're tearing down the address space then we only care about >> * invalidating the walk-cache, since the ASID allocator won't >> * reallocate our ASID without invalidating the entire TLB. >> */ >> if (tlb->fullmm) { >> if (!last_level) >> flush_tlb_mm(tlb->mm); >> return; >> } >> >> But currently tlb_mmu_finish() can mistakenly set fullmm incorrectly (if >> mm_tlb_flush_nested() is true), which might skip the TLB flush. > > But in that case isn't 'freed_tables' set to 1, so 'last_level' will be > false and we'll do the flush in the code above? Indeed. You are right. So no rush.
