On Tue, Sep 01, 2026 at 06:11:57PM +0100, Kiryl Shutsemau wrote: > On Tue, Sep 01, 2026 at 04:45:14PM +0100, Lorenzo Stoakes (ARM) wrote: > > > munmap() of 64G worth of THP should be enough to demonstrate the > > > problem. > > > > I mean you're going to hit that from RCU freeing page tables already, which > > most architectures already do right? > > Not at the same rate -- tlb_remove_table() batches into struct > mmu_table_batch. One call_rcu() per MAX_TABLE_BATCH. > > > So if RCU saturation is a problem, that problem already exists, but I've > > not heard of that being a problem at all? > > I did quick test and I don't see a measurable difference in munmap() > wall time of 40G of THPs. I see ~17x more softirqs, but this is > expected. > > The objection is retracted. > > We can return to this later if it is going to be visible anywhere.
Great thanks! :) > > -- > Kiryl Shutsemau / Kirill A. Shutemov -- Cheers, Lorenzo
