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charset="UTF-8" X-Rspam-User: X-Rspamd-Server: rspam03 X-Stat-Signature: n4mhqyoxb756cqoz1iofpw137mxs8omd X-Rspamd-Queue-Id: 8106140006 X-HE-Tag: 1674680119-202631 X-HE-Meta: U2FsdGVkX1+98EXqjKkd1bHPlRAVOsGVb+EBhjiik/lCLCdLlcRp+G54U3igvYg8LggjcAMqbonIaU6YTNFs7SYKdRcAswtC6xEHj4xPrjwij0PkYa2NOwE4uXm7RInTeKlTkFYx30RdkjabZQZN/YN05K5FjX42TkA2p7imWHOZFmbKAYre5TgktdLeHYG63GRqeXd6vnrRZSJLiFFoTviOhFuuAxFgbGxM8JQJ4nqNL0kNpc617MK7RlY3n6RkPEO/LIRVheKszwQLtKoNOsYv3Wv1QEQDNAqVzkUwpDDbkYmlK9stRlO6y1mX/8nn9fNDDFbS/x0rFFatWG1Ag0XitupglCWssBXPFhB4tNAnMUoEf/AP/LO/Iyoh1D8z+m8b9oANiaRElAwpRTybRyO5qgr+gxSX371hMj8Nmh8Q6kU4DbfLxZbWilcxqgtMJTj8SsTASn4/c0eXRQhRVRASxewhXeIIC6FM5B3Ohyu6JHyiKclzg7/BcGH4Dh2XwzvDysvSnetO+yB3ZGvlCVoDCxpe7BSluc3q5+5KA1Ly4mNQ0lHqp9pXzH4/pFRbz+f4/7qnWOf2A0x4/7rIZJiArFo402YmcbQMsXH47UaSrfRRNllD24uvW1V8ZgKLSABQSzemrvG+Ug8Oh3BZYK7T3yI+ML9thKJsQ+vGaiFOzHCc7eApxFgT39fRRi/+FDVsAQMTTMZE4bSuxpF4phijEioFPS2/BcYrVebQU3suNK10uJLkapTg8ais0/jwscfKAU7BqUAlcs9oU3iPokyvQti7hToJdCiZ7a4xJ0GXlaADiSKeV0mwHyDVc1GMeQ+j0DsTScPelrOYT6WPyqiYaEgqAV/KAuRrRH8qeFj6rqNujRJ+xUjUzAgKC+0Jeb7vCkHV1WkTuxuNVVCGFn89pJMgd+7etIJSYJqPjpth866mWY71Kl5rgUdNPTeUailGBpbSWaq/qHEsw4y BEciVrh9 GjYOFY2iTn0Zy85JoJabelTdiRkBQW9NWXRwoT5TwLNeLhZNJoEbxnrYNeby2rmX/q42oJdEJz1oLROqC0om1h1KEXbeSmRICG5YrDIzsUF+YDKy3yX5/VwTxcNwD00ms4/q3JcJ0jrHG6/OZjkvVCTA309VJsH5v3FldhxguKMpJXU3uAdzsSPQhXAAlL5w1nBjtHGXUb+CDiiLBcBhxelqMek2up/+D9wkfye//If3A3NM/SHxvfoO0txasEbVv31rP33VIHJ6NHGPVUQ04oq4laVVN6oNpviA0+li42E/9YteSy0ZJ2WZWehtSAXJ03XjAwxJoa8zs0NqSk/lbArnCG3hSzEa9jZgyAE8Habq11H/Dy8xxh5eUmN1qXADY8Gyd38aFUwWCIgfGM44J6skqjqV+emu285Yl 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, Jan 25, 2023 at 1:23 PM Dan Williams wrote: > > Commit 6e9f05dc66f9 ("libnvdimm/pfn_dev: increase MAX_STRUCT_PAGE_SIZE") > > ...updated MAX_STRUCT_PAGE_SIZE to account for sizeof(struct page) > potentially doubling in the case of CONFIG_KMSAN=y. Unfortunately this > doubles the amount of capacity stolen from user addressable capacity for > everyone, regardless of whether they are using the debug option. Revert > that change, mandate that MAX_STRUCT_PAGE_SIZE never exceed 64, but > allow for debug scenarios to proceed with creating debug sized page maps > with a compile option to support debug scenarios. > > Note that this only applies to cases where the page map is permanent, > i.e. stored in a reservation of the pmem itself ("--map=dev" in "ndctl > create-namespace" terms). For the "--map=mem" case, since the allocation > is ephemeral for the lifespan of the namespace, there are no explicit > restriction. However, the implicit restriction, of having enough > available "System RAM" to store the page map for the typically large > pmem, still applies. > > Fixes: 6e9f05dc66f9 ("libnvdimm/pfn_dev: increase MAX_STRUCT_PAGE_SIZE") > Cc: > Cc: Alexander Potapenko > Cc: Marco Elver > Reported-by: Jeff Moyer Thanks -- that BUILD_BUG_ON() has been a nuisance for some of my debug configs. Acked-by: Yu Zhao