Re: [PATCH v4 00/12] mm: make userland page table freeing RCU-safe
From: Andrew Morton <akpm@linux-foundation.org>
Date: 2026-09-22 23:00:24
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On Tue, 22 Sep 2026 16:35:31 +0100 "Lorenzo Stoakes (ARM)" [off-list ref] wrote:
The majority of architectures in the kernel defer page table freeing until an RCU grace period has elapsed, this series converts all remaining architectures to do so too and eliminates CONFIG_MMU_GATHER_RCU_TABLE_FREE altogether. This is important because it enables safe lockless page table walking under RCU alone.
Do we have reason to believe that anyone is seeing any effects from their arch's failure to rcu-free the page tables? This sounds like a rather long-standing wart, yes? The patchset is thinly reviewed and mm.git is bursting at the seams again. I'll play wait-and-see on this series. Feel free to cluebat me if that's a bad call.