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protected-headers=v1; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Subject: Re: [PATCH v9 01/10] memblock: Introduce MEMBLOCK_LLMAP MIME-Version: 1.0 On Tue, Sep 08, 2026 at 10:40:16AM +0300, Mike Rapoport wrote: > On Mon, Sep 07, 2026 at 10:50:12AM +0100, Vincent Donnefort wrote: > > On Sun, Sep 06, 2026 at 10:33:11PM +0300, Mike Rapoport wrote: > > > On Wed, Sep 02, 2026 at 11:47:03AM +0100, Vincent Donnefort wrote: > > > > Keeping last-level mappings is interesting on some architectures as= it > > > > allows mapping/unmapping pages from the kernel direct map without t= he > > > > risk of splitting blocks which, under the break-before-make rule, m= ay > > > > trigger page-faults the kernel can't handle. > > > >=20 > > > > However, mapping the entire direct map at PTE-level is costly. So > > > > instead, create a new memblock flag MEMBLOCK_LLMAP to enable the sy= stem > > >=20 > > > I believe MEMBLOCK_PTE_MAP sounds more descriptive. > >=20 > > The idea was to have something close from NOMAP, to emphasis it is one = or the > > other. But PTE_MAP sounds good too. >=20 > Could be PTEMAP if you prefer. > My point was that unlike PTE, "LL" is not perceived as last-level, it > should be looked up. We were discussing the concept of enabling entire block mappings to be removed at once from the linear map, so at that point "PTE"MAP may no longer be accurate. I imagine that in some scenarios we might be able to go to PUD mappings for something like VPR (say systems with a fair amount of system memory and we want to carve out 4 GiB for VPR, split into four 1 GiB chunks). 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