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(p200300cbc70dee00b271fb6ca9314769.dip0.t-ipconnect.de. [2003:cb:c70d:ee00:b271:fb6c:a931:4769]) by smtp.gmail.com with ESMTPSA id 20-20020a05600c22d400b004054dcbf92asm981775wmg.20.2023.10.12.02.31.19 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 12 Oct 2023 02:31:20 -0700 (PDT) Message-ID: <0feef130-59dd-0a31-ed06-e3849a52c75e@redhat.com> Date: Thu, 12 Oct 2023 11:31:19 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.15.1 Subject: Re: [PATCH v6 4/9] mm: thp: Introduce anon_orders and anon_always_mask sysfs files To: Andrew Morton , Michael Ellerman Cc: Ryan Roberts , "Aneesh Kumar K.V" , Matthew Wilcox , Yin Fengwei , Yu Zhao , Catalin Marinas , Anshuman Khandual , Yang Shi , "Huang, Ying" , Zi Yan , Luis Chamberlain , Itaru Kitayama , "Kirill A. Shutemov" , John Hubbard , David Rientjes , Vlastimil Babka , Hugh Dickins , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org References: <20230929114421.3761121-1-ryan.roberts@arm.com> <20230929114421.3761121-5-ryan.roberts@arm.com> <20230929155530.a51e68e03e47a06b6b84c689@linux-foundation.org> <87fs2mrqld.fsf@mail.lhotse> <20231009172029.e558c08dd90d9b94fec3a036@linux-foundation.org> From: David Hildenbrand Organization: Red Hat In-Reply-To: <20231009172029.e558c08dd90d9b94fec3a036@linux-foundation.org> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 43169160015 X-Stat-Signature: sy1kwu5gsm95jp6ytmxe7wg1ryewx76u X-HE-Tag: 1697103085-70480 X-HE-Meta: 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 ZBkkoyxE 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 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 10.10.23 02:20, Andrew Morton wrote: > On Sun, 08 Oct 2023 09:54:22 +1100 Michael Ellerman wrote: > >>> I don't know why powerpc's PTE_INDEX_SIZE is variable. >> >> To allow a single vmlinux to boot using either the Hashed Page Table >> MMU, or Radix Tree MMU, which have different page table geometry. >> >> That's a pretty crucial feature for distros, so that they can build a >> single kernel to boot on Power8/9/10. > > Dumb question: why can't distros ship two kernels and have the boot > loader (or something else) pick the appropriate one? One answer I keep hearing over and over again is "test matrix explosion". So distros only do it when unavoidable: for example, when differing PAGE_SIZE is required (e.g., 4k vs 64k) or we're dealing with RT support (RT vs !RT). -- Cheers, David / dhildenb