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bh=3E/iTIUJJkvc1INMX+hV7mwu+9e7TWyhmO9W4jtcTrE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mklI3sjRGVRE2S0fjtQ9dVh3DGS7T6DusRIAlI0MIptSQ6T8wc46BR/RWzKMyzCHX bqKriBixydwP6TDfRV1UevEH+6KQiaaF7FNRWIYCLT3mYQEHHoybn3vEJgwDu9ORhz mkE+b83p9fDYJ7YFUkYyzaI3yv6BMqCStFpPcDtdMEjtVPO/BJzv92gqH5+fz0/ZR6 1V5kOvDfOEWEhOOUkpxHHTePtKRnPwwIZ4dpiDntJ9fUsdHLJoveAJq6uibuo3uON/ yUjEDN8HKJEajwxJQpiWA5RQ/70KWoqs5HiIAHBVS3THgLiSUGRISJjA5SORYQ1q/M AWnU2iR6CPjNg== Date: Wed, 8 Feb 2023 11:44:42 +0200 From: Mike Rapoport To: David Hildenbrand Cc: Matthew Wilcox , Hyeonggon Yoo <42.hyeyoo@gmail.com>, Vlastimil Babka , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Roman Gushchin , HORIGUCHI =?utf-8?B?TkFPWUEo5aCA5Y+jIOebtOS5nyk=?= , Joe Perches , Petr Mladek , Andy Shevchenko , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Alexander Potapenko , Marco Elver Subject: Re: [RFC v3 2/4] mm: move PG_slab flag to page_type Message-ID: References: <20221218101901.373450-1-42.hyeyoo@gmail.com> <20221218101901.373450-3-42.hyeyoo@gmail.com> <15fda061-72d9-2ee9-0e9f-6f0f732a7382@suse.cz> <59630801-42b4-22e8-0ef6-5a5b8636dfbd@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <59630801-42b4-22e8-0ef6-5a5b8636dfbd@redhat.com> X-Stat-Signature: aw5z3es1do783rtuctzwy31e7nojwcd3 X-Rspam-User: X-Rspamd-Queue-Id: 78DB9140015 X-Rspamd-Server: rspam06 X-HE-Tag: 1675849500-663683 X-HE-Meta: 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 5xPHuJKE QmjDtWaZlVihpAUXACq336ooj8mTrFD/PoDc4qiq1Ll0vsc6CNyI49sUOwYLykFh+Z2ZjbMCzNKC6/GgREr0VCD0/3IUlF5JjNrv77Bg1Zecg/jfhzKJ6PG7anechUioxGs2fSqkbTR27wXO42Q7G7mYwg2Z+GHqUQ7JCVtixja83LRiso+GRIo/Lmk08X2n6JWQh5qin45HdIy10RvrR+vCKGGov3SHqEJSOjFxyHbzLuoBos4uSc6YuDRQhEwa+TUB2ICaPIipE9WARDd6RutQhWcHSHy9h32s+yKIVEQJEqaxlLmGjgKVLqjIyBB5SWyTWnrn8t/cPJPYkBeH6lX50boZGXt8+ffpSbxNGK/ZFIE8yVd9mDqE+7CRa9roPndYIxErTH/lRO+sKpG/Gfcv7V59niQAIorWjKvwpnpXoJqI= 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 Fri, Feb 03, 2023 at 05:04:01PM +0100, David Hildenbrand wrote: > On 30.01.23 06:11, Matthew Wilcox wrote: > > On Mon, Jan 30, 2023 at 01:34:59PM +0900, Hyeonggon Yoo wrote: > > > > Seems like quite some changes to page_type to accomodate SLAB, which is > > > > hopefully going away soon(TM). Could we perhaps avoid that? > > > > > > If it could be done with less changes, I'll try to avoid that. > > > > Let me outline the idea I had for removing PG_slab: > > > > Observe that PG_reserved and PG_slab are mutually exclusive. Also, > > I recall that there are SetPageReserved() calls on pages allocated via slab. I did a quick scan, and it seems that all allocated reserved pages come from alloc_pages() or vmalloc(). BTW, looking at the current usage of SetPageReserved, it seems that some are bogus/historical and some would justify a different page type if we are to have 15 bits for PG_kernel. > -- > Thanks, > > David / dhildenb -- Sincerely yours, Mike.