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Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Vishal Moola , Ingo Molnar , Lu Baolu , Jason Gunthorpe , Steven Rostedt , x86@kernel.org, linux-mm@kvack.org, regressions@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: don't defer freeing kernel page tables while booting Message-ID: References: <41a59ba9-039e-454f-8d31-f647db802ada@kernel.org> <20260924072819.33277-1-mikhail.v.gavrilov@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260924072819.33277-1-mikhail.v.gavrilov@gmail.com> X-Stat-Signature: p4nh1a8g1ac7u3ybeqr7bun4ercotx3u X-Rspam-User: X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 399AE1C0004 X-HE-Tag: 1790235506-962789 X-HE-Meta: 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 ATNb/t74 virHcrFhxFxBz07Dgrs4sDB8xBrCW/MRZgCjbPGzT8RAx1C9hAsYyCMX3IfTBjx+aE+kZZxWHt9mTs5mrzav4QOLWV0q/H4UEVtT1LVYCCuASGP8SbC824Ahwbh2eArBkj5fKZXRE7NbHT4QcMxJaDwupTphQiJwJtJ6db4GJgT36dAq7KnIYOBHhFQqPxbKtmZ4ljwtt3BMvi5IFCcX2+FsnOW9YfDslAWLGJHcBOOZk4+pWV74JnQeh2rgxUsRC809fjvQv7nCO8k6Bof3Gl6n0of72uXileZnQF46qkdSRACCe4mA6u/zeJYq8GwWc/muVxar5L5Y2bcU= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Sep 24, 2026 at 12:28:19PM +0500, Mikhail Gavrilov wrote: > On 9/24/26 09:07, David Hildenbrand (Arm) wrote: > > Should we instead simply skip the > > > > schedule_work(&kernel_pgtable_work.work); > > > > and rely on anybody freeing stuff later to just free that one alongside? > > > > That avoids throwing in more freeing handling. > > Yes, that is simpler, and the early table then goes through the same > IOMMU flush as every other one, so there is no need to reason about > what an IOMMU can see during boot. The only cost is that it waits on > the list until the next kernel page table is freed after boot. > > I'll send a v2 that way once I have booted it here. Please wait for me to have a look through this issue before respinning, please. -- Cheers, Lorenzo