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bh=zG2cqcDSXyzEvp5pVF9J1GNp84hIzLKr5Bwlm1OtUos=; b=gU/WiIJ1BU4DQUQMKdQb6/svhRWKwGQsRZBds3/5sGYpdgR4WMz9LDyZNieFLEdIicT/0i X5yZTflhYx4w5nvlAc9tBS0i4RMhTktT7AMzHgEjUwl+ggXvhjjlJie5rViHvDPkdihX6/ e6dT/NjCLP4pM85lKHZe3+41SYMGKpw= X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 8E2494009A X-Stat-Signature: fms6fqx3qbfp7cui7tafspiszukjerfe Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=fYDb7qEj; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b="UKL/MDgb"; spf=pass (imf01.hostedemail.com: domain of osalvador@suse.de designates 195.135.220.28 as permitted sender) smtp.mailfrom=osalvador@suse.de; dmarc=pass (policy=none) header.from=suse.de X-Rspam-User: X-HE-Tag: 1655459664-950044 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, Jun 17, 2022 at 09:43:33AM +0200, David Hildenbrand wrote: > VmemmapSelfHosted, then the function names get nicer. Definitely. > > > +#endif > > + > > /* > > * On an anonymous page mapped into a user virtual memory area, > > * page->mapping points to its anon_vma, not to a struct address_space; > > diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c > > index 1089ea8a9c98..e2de7ed27e9e 100644 > > --- a/mm/hugetlb_vmemmap.c > > +++ b/mm/hugetlb_vmemmap.c > > @@ -101,6 +101,14 @@ void hugetlb_vmemmap_free(struct hstate *h, struct page *head) > > { > > unsigned long vmemmap_addr = (unsigned long)head; > > unsigned long vmemmap_end, vmemmap_reuse, vmemmap_pages; > > + struct mem_section *ms = __pfn_to_section(page_to_pfn(head)); > > + struct page *memmap; > > + > > + memmap = sparse_decode_mem_map(ms->section_mem_map, > > + pfn_to_section_nr(page_to_pfn(head))); > > Why can't we check the head page directly? Either I need more coffee or > this can be simplified. Uhm, maybe I'm the one who needs coffe here but we have something like: [ hot-plugges section ] [memmap pages][normal pages] we only mark as VmemmapSelfHosted the memmap pages. head page points to [normal pages] range, that is why we need to go and get its mem_map to see whether those pages are marked. Does it make sense? Or am I missing something? > > + > > + if (PageVmemmap_self_hosted(memmap)) > > Maybe that's the right place for a comment, an ascii art, and how it is > safe to only check the first vmemmap page due to alignment restrictions. Yes, definitely worth putting in a comment. > > + /* > > + * Let us flag self-hosted memmap > > + */ > > I think that comment can be dropped because the code does exactly that. Yeah, was mainly to picture it, but it needs to go as it is worthless. -- Oscar Salvador SUSE Labs