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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: D8A6A140015 X-Stat-Signature: 9b9ebafmqs5pmia3whqbpcpufo4cxo6h X-Rspam-User: X-HE-Tag: 1756472991-733895 X-HE-Meta: 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 GR0gZuNh ribXx0aF3kj9IYDUzma2Sf93MK5F5DHtJSLJvwMNSKe2d49yu9++LLokfuaXFxDu5RuqjV+/UnpQ81y0bMQFsi7APbar4C5iZE1xFpKyJzTDSuK5KYUP5ozxH40NbxRPsZfxwomb+ZufZgGt6zcIf/cZuW2bCwxIFpIxHrJQ/S19R6UTVB0jVp6OdWOC6l37n3i8WMl+rxhQiwAJDO2NiQmKs9JMJJRKtJ9ZiY20z5vfJEZ4tWj0gdd0agVAnNa2YdpYwGkWVt8BVy9MG7Xrc8dnK7I2Z3mFHCn3TM+VqqYXqjOWlJYUfqAGCl12ANCQshc9UJYZ+2K2QzQX1nJ1m4tZD8FG8nsZFJIQ62xjXgCS4YKYJJWC3/UTpIC0U3Yy3hWzjEm24cEYQdIVxABEO01+cjquE5anr+7sFNTpTon6vfe9vbVrY34kBvYs/Qbi94meucwHg+WdZ7/2muo6py51/LgJbYqZYkG3L 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: List-Subscribe: List-Unsubscribe: > > It seems a bit arbitrary, like we open-code this (at risk of making a mistake) > in some places but not others. [...] >> >> One could argue that maybe one would want a order_to_pages() helper (that >> could use BIT() internally), but I am certainly not someone that would >> suggest that at this point ... :) > > I mean maybe. > > Anyway as I said none of this is massively important, the open-coding here is > correct, just seems silly. Maybe we really want a ORDER_PAGES() and PAGES_ORDER(). But I mean, we also have PHYS_PFN() PFN_PHYS() and see how many "<< PAGE_SIZE" etc we are using all over the place. > >> >>> >>>> + >>>> /* >>>> * compound_nr() returns the number of pages in this potentially compound >>>> * page. compound_nr() can be called on a tail page, and is defined to >>>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c >>>> index baead29b3e67b..426bc404b80cc 100644 >>>> --- a/mm/page_alloc.c >>>> +++ b/mm/page_alloc.c >>>> @@ -6833,6 +6833,7 @@ static int __alloc_contig_verify_gfp_mask(gfp_t gfp_mask, gfp_t *gfp_cc_mask) >>>> int alloc_contig_range_noprof(unsigned long start, unsigned long end, >>>> acr_flags_t alloc_flags, gfp_t gfp_mask) > > Funny btw th > >>>> { >>>> + const unsigned int order = ilog2(end - start); >>>> unsigned long outer_start, outer_end; >>>> int ret = 0; >>>> >>>> @@ -6850,6 +6851,9 @@ int alloc_contig_range_noprof(unsigned long start, unsigned long end, >>>> PB_ISOLATE_MODE_CMA_ALLOC : >>>> PB_ISOLATE_MODE_OTHER; >>>> >>>> + if (WARN_ON_ONCE((gfp_mask & __GFP_COMP) && order > MAX_FOLIO_ORDER)) >>>> + return -EINVAL; >>> >>> Possibly not worth it for a one off, but be nice to have this as a helper function, like: >>> >>> static bool is_valid_order(gfp_t gfp_mask, unsigned int order) >>> { >>> return !(gfp_mask & __GFP_COMP) || order <= MAX_FOLIO_ORDER; >>> } >>> >>> Then makes this: >>> >>> if (WARN_ON_ONCE(!is_valid_order(gfp_mask, order))) >>> return -EINVAL; >>> >>> Kinda self-documenting! >> >> I don't like it -- especially forwarding __GFP_COMP. >> >> is_valid_folio_order() to wrap the order check? Also not sure. > > OK, it's not a big deal. > > Can we have a comment explaining this though? As people might be confused > as to why we check this here and not elsewhere. I can add a comment. -- Cheers David / dhildenb