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charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 502438000F X-Stat-Signature: kdrhexuyzr9qxabprz5sajjqu8ypwiig X-Rspam-User: X-Spamd-Result: default: False [2.89 / 9.00]; IRL_BL_25(2.00)[52.25.139.140:received]; SUBJECT_HAS_UNDERSCORES(1.00)[]; BAYES_HAM(-0.21)[65.92%]; RCVD_NO_TLS_LAST(0.10)[]; MIME_GOOD(-0.10)[text/plain]; BAD_REP_POLICIES(0.10)[]; DKIM_TRACE(0.00)[kernel.org:+]; TO_MATCH_ENVRCPT_SOME(0.00)[]; DMARC_POLICY_ALLOW(0.00)[kernel.org,none]; FROM_EQ_ENVFROM(0.00)[]; RCPT_COUNT_TWELVE(0.00)[13]; MIME_TRACE(0.00)[0:+]; RCVD_COUNT_THREE(0.00)[4]; ARC_SIGNED(0.00)[hostedemail.com:s=arc-20220608:i=1]; PREVIOUSLY_DELIVERED(0.00)[linux-mm@kvack.org]; R_DKIM_ALLOW(0.00)[kernel.org:s=k20201202]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; FROM_HAS_DN(0.00)[]; R_SPF_ALLOW(0.00)[+a:ams.source.kernel.org]; TO_DN_SOME(0.00)[]; TO_DN_EQ_ADDR_SOME(0.00)[] X-Rspamd-Server: rspam08 X-HE-Tag: 1670441401-140028 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Dec 7, 2022 at 8:54 AM Christophe Leroy wrote: > > > > Le 07/12/2022 =C3=A0 16:36, Thomas Gleixner a =C3=A9crit : > > > > The "use free space in existing mappings" mechanism is not required to > > be PMD_SIZE based, right? > > > > Large page size, strict separation: > > > > struct mod_alloc_type_params { > > [MOD_ALLOC_TYPE_TEXT] =3D { > > .mapto_type =3D MOD_ALLOC_TYPE_TEXT, > > .flags =3D FLAG_SHARED_PMD | FLAG_SECOND= _ADDRESS_SPACE, > > .granularity =3D PMD_SIZE, > > .alignment =3D MOD_ARCH_ALIGNMENT, > > .start[0] =3D MODULES_VADDR, > > .end[0] =3D MODULES_END, > > .start[1] =3D MODULES_VADDR_2ND, > > .end[1] =3D MODULES_END_2ND, > > .pgprot =3D PAGE_KERNEL_EXEC, > > .fill =3D text_poke, > > .invalidate =3D text_poke_invalidate, > > }, > > Don't restrict implementation to PMD_SIZE only. > > On powerpc 8xx: > - PMD_SIZE is 4 Mbytes > - Large pages are 512 kbytes and 8 Mbytes. > > It even has large pages of size 16 kbytes when build for 4k normal page > size. IIUC, these customizations would fit nicely with this design. I will see ho= w much I can prototype with powerpc without the actual hardwares. Thanks, Song