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charset=us-ascii Content-Disposition: inline In-Reply-To: <24d5ec20-9c9e-93aa-11f4-c4619f51f7d1@redhat.com> ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1655444817; a=rsa-sha256; cv=none; b=n0sMkMdhGbbNefBxOPkHJPjpwUJfEqS8WWlDVG6O4wnivBLrSQzFftaY+NrlXAZ6ZE3aHB fIcPcHwxNIYa3JWWeKEq08/VynJR4dHqPBDS/mc4JHuIqxhlqQClR9J8py8Ggv7PR/He5L XPgJni0+2zYPQnJPOCkWkxgjjolkBIo= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=M8mPJFXa; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=y9n6WNPT; spf=pass (imf10.hostedemail.com: domain of osalvador@suse.de designates 195.135.220.29 as permitted sender) smtp.mailfrom=osalvador@suse.de; dmarc=pass (policy=none) header.from=suse.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1655444817; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=3nN0uwMwYHIGnvGf1je2kTJf72RD7LvC05n350gAJao=; b=r+k0g8wx6Hi6M3Y3DoV5acXlWBFmfd5yHDwCFM1NXFUpI9LxQ4kwpdsFRyOdTebqdkaJpA 1IMzRChJSbSWF3szOeTN45RXsCOHbWTifAsISlf8x8EEg6hciSoB6Rrm42i/WZm100Qunt 1d5g6D5voc25QCvC7nnXghLB0xGCmpM= X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 40908C0072 X-Stat-Signature: dpis3g9gq54m8as7g3zxkwfhe84qa5uy Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=M8mPJFXa; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=y9n6WNPT; spf=pass (imf10.hostedemail.com: domain of osalvador@suse.de designates 195.135.220.29 as permitted sender) smtp.mailfrom=osalvador@suse.de; dmarc=pass (policy=none) header.from=suse.de X-Rspam-User: X-HE-Tag: 1655444817-195069 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 Thu, Jun 16, 2022 at 09:30:33AM +0200, David Hildenbrand wrote: > IIRC, that was used to skip these patches on the offlining path before > we provided the ranges to offline_pages(). Yeah, it was designed for that purpose back then. > I'd not mess with PG_reserved, and give them a clearer name, to not > confuse them with other, ordinary, vmemmap pages that are not > self-hosted (maybe in the future we might want to flag all vmemmap pages > with a new type?). Not sure whether a new type is really needed, or to put it another way, I cannot see the benefit. > > I'd just try reusing the flag PG_owner_priv_1. And eventually, flag all > (v)memmap pages with a type PG_memmap. However, the latter would be > optional and might not be strictly required > > > So what think could make sense is > > /* vmemmap pages that are self-hosted and cannot be optimized/freed. */ > PG_vmemmap_self_hosted = PG_owner_priv_1, Sure, I just lightly tested the below, and seems to work, but not sure whether that is what you are referring to. @Munchun: thoughts? diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index e66f7aa3191d..a4556afd7bda 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -193,6 +193,11 @@ enum pageflags { /* Only valid for buddy pages. Used to track pages that are reported */ PG_reported = PG_uptodate, + +#ifdef CONFIG_MEMORY_HOTPLUG + /* For self-hosted memmap pages */ + PG_vmemmap_self_hosted = PG_owner_priv_1, +#endif }; #define PAGEFLAGS_MASK ((1UL << NR_PAGEFLAGS) - 1) @@ -628,6 +633,10 @@ PAGEFLAG_FALSE(SkipKASanPoison, skip_kasan_poison) */ __PAGEFLAG(Reported, reported, PF_NO_COMPOUND) +#ifdef CONFIG_MEMORY_HOTPLUG +PAGEFLAG(Vmemmap_self_hosted, vmemmap_self_hosted, PF_ANY) +#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))); + + if (PageVmemmap_self_hosted(memmap)) + return; vmemmap_pages = hugetlb_optimize_vmemmap_pages(h); if (!vmemmap_pages) @@ -199,10 +207,10 @@ static struct ctl_table hugetlb_vmemmap_sysctls[] = { static __init int hugetlb_vmemmap_sysctls_init(void) { /* - * If "memory_hotplug.memmap_on_memory" is enabled or "struct page" - * crosses page boundaries, the vmemmap pages cannot be optimized. + * If "struct page" crosses page boundaries, the vmemmap pages cannot + * be optimized. */ - if (!mhp_memmap_on_memory() && is_power_of_2(sizeof(struct page))) + if (is_power_of_2(sizeof(struct page))) register_sysctl_init("vm", hugetlb_vmemmap_sysctls); return 0; diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 1213d0c67a53..863966c2c6f1 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -45,8 +45,6 @@ #ifdef CONFIG_MHP_MEMMAP_ON_MEMORY static int memmap_on_memory_set(const char *val, const struct kernel_param *kp) { - if (hugetlb_optimize_vmemmap_enabled()) - return 0; return param_set_bool(val, kp); } @@ -1032,6 +1030,7 @@ int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages, { unsigned long end_pfn = pfn + nr_pages; int ret; + int i; ret = kasan_add_zero_shadow(__va(PFN_PHYS(pfn)), PFN_PHYS(nr_pages)); if (ret) @@ -1039,6 +1038,12 @@ int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages, move_pfn_range_to_zone(zone, pfn, nr_pages, NULL, MIGRATE_UNMOVABLE); + /* + * Let us flag self-hosted memmap + */ + for (i = 0; i < nr_pages; i++) + SetPageVmemmap_self_hosted(pfn_to_page(pfn + i)); + /* * It might be that the vmemmap_pages fully span sections. If that is * the case, mark those sections online here as otherwise they will be -- Oscar Salvador SUSE Labs