From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: ARC-Seal: i=1; a=rsa-sha256; t=1522169534; cv=none; d=google.com; s=arc-20160816; b=Y0cL4EwqPAjcnjRnhDX1inHOe3DLja1mItJXrtY73x865ujrhV9MvknI9z5w4S/tKs L6TFjsgLr4eeD3k1c6NzhfGqUp6hortUrUdb0nTMa3LTxoHqmcOWiuTR+FyUJEhRsOBG ruP+E+PdnzgZTjvXd3abTRQ8+EpjEPjtsOHj4qO/I1t03WhypkhhoAc51wDTqVDbMHVA MOonc6hn4mLBk28pYe/AZHrl4k7r7SV1FS+8tBKpJ1Yj3eR/NTTJQRJb25EyZmpPqwtU opYiNeUtO/w268ZT1JqbBudvrQNqe8Q0xAZEIYxxlyejUwnGpC94HDq1yOF2txffEH9v KFOg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=cc:to:subject:message-id:date:from:references:in-reply-to :mime-version:arc-authentication-results; bh=fpTu0XMT7RHL0wQ8oipUUHDiPWFNbA8LO8g2LeHdXz4=; b=rprwaJQpCbb+msr7zjyQsUi348jxUSR62n/RUJdwHdC2WZ3VxElJ2iXg1FxwzXABqH HtnQzbh66wBehhCoy0TQWqoauz8r0FtoGTuBfSXYu12U9BwxVIFNqwfQ8EGcq8K1ZNeG VviZ0JM6j0xDITU1hQupqRoeWtYUfrWBG9zqAsLgQ8kV0WvW5uCNtxs5imCdrXqBdtE+ O2OwV8v7px/T0ShYVJjPZGJudeOunzUJb5s4AozuW3LWAiMkW+uKWtSz5EOUflZ8Isqj D7MXjKyhii9TJsJ1CMSPrYbZqS46mEjEpYeCq9aloLrRVf90C3pbEPZbuj1ze+hZ3fPg YJcw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of dvacek@redhat.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=dvacek@redhat.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Authentication-Results: mx.google.com; spf=pass (google.com: domain of dvacek@redhat.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=dvacek@redhat.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com X-Google-Smtp-Source: AIpwx49ob9hcTtqasxqry/WotEBx+XpCl6wA4GqrY51SsR/mVs1ZqH6OpTmEBSVpzDxLhWREjsttUPMoDx3Y5HVZ0Hs= MIME-Version: 1.0 In-Reply-To: <1521894282-6454-2-git-send-email-hejianet@gmail.com> References: <1521894282-6454-1-git-send-email-hejianet@gmail.com> <1521894282-6454-2-git-send-email-hejianet@gmail.com> From: Daniel Vacek Date: Tue, 27 Mar 2018 18:52:13 +0200 Message-ID: Subject: Re: [PATCH v2 1/5] mm: page_alloc: remain memblock_next_valid_pfn() when CONFIG_HAVE_ARCH_PFN_VALID is enable To: Jia He Cc: Andrew Morton , Michal Hocko , Catalin Marinas , Mel Gorman , Will Deacon , Mark Rutland , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Pavel Tatashin , Daniel Jordan , AKASHI Takahiro , Gioh Kim , Steven Sistare , Eugeniu Rosca , Vlastimil Babka , open list , linux-mm@kvack.org, James Morse , Ard Biesheuvel , Steve Capper , x86@kernel.org, Greg Kroah-Hartman , Kate Stewart , Philippe Ombredanne , Johannes Weiner , Kemi Wang , Petr Tesarik , YASUAKI ISHIMATSU , Andrey Ryabinin , Nikolay Borisov , Jia He Content-Type: text/plain; charset="UTF-8" X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1595821857199891353?= X-GMAIL-MSGID: =?utf-8?q?1596110442017548118?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Sat, Mar 24, 2018 at 1:24 PM, Jia He wrote: > Commit b92df1de5d28 ("mm: page_alloc: skip over regions of invalid pfns > where possible") optimized the loop in memmap_init_zone(). But it causes > possible panic bug. So Daniel Vacek reverted it later. > > But memblock_next_valid_pfn is valid when CONFIG_HAVE_ARCH_PFN_VALID is > enabled. And as verified by Eugeniu Rosca, arm can benifit from this > commit. So remain the memblock_next_valid_pfn. It is not dependent on CONFIG_HAVE_ARCH_PFN_VALID option but on arm(64) implementation of pfn_valid() function, IIUC. So it should really be moved from generic source file to arm specific location. I'd say somewhere close to the pfn_valid() implementation. Such as to arch/arm{,64}/mm/ init.c-ish? --nX > Signed-off-by: Jia He > --- > include/linux/memblock.h | 4 ++++ > mm/memblock.c | 29 +++++++++++++++++++++++++++++ > mm/page_alloc.c | 11 ++++++++++- > 3 files changed, 43 insertions(+), 1 deletion(-) > > diff --git a/include/linux/memblock.h b/include/linux/memblock.h > index 0257aee..efbbe4b 100644 > --- a/include/linux/memblock.h > +++ b/include/linux/memblock.h > @@ -203,6 +203,10 @@ void __next_mem_pfn_range(int *idx, int nid, unsigned long *out_start_pfn, > i >= 0; __next_mem_pfn_range(&i, nid, p_start, p_end, p_nid)) > #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ > > +#ifdef CONFIG_HAVE_ARCH_PFN_VALID > +unsigned long memblock_next_valid_pfn(unsigned long pfn); > +#endif > + > /** > * for_each_free_mem_range - iterate through free memblock areas > * @i: u64 used as loop variable > diff --git a/mm/memblock.c b/mm/memblock.c > index ba7c878..bea5a9c 100644 > --- a/mm/memblock.c > +++ b/mm/memblock.c > @@ -1102,6 +1102,35 @@ void __init_memblock __next_mem_pfn_range(int *idx, int nid, > *out_nid = r->nid; > } > > +#ifdef CONFIG_HAVE_ARCH_PFN_VALID > +unsigned long __init_memblock memblock_next_valid_pfn(unsigned long pfn) > +{ > + struct memblock_type *type = &memblock.memory; > + unsigned int right = type->cnt; > + unsigned int mid, left = 0; > + phys_addr_t addr = PFN_PHYS(++pfn); > + > + do { > + mid = (right + left) / 2; > + > + if (addr < type->regions[mid].base) > + right = mid; > + else if (addr >= (type->regions[mid].base + > + type->regions[mid].size)) > + left = mid + 1; > + else { > + /* addr is within the region, so pfn is valid */ > + return pfn; > + } > + } while (left < right); > + > + if (right == type->cnt) > + return -1UL; > + else > + return PHYS_PFN(type->regions[right].base); > +} > +#endif /*CONFIG_HAVE_ARCH_PFN_VALID*/ > + > /** > * memblock_set_node - set node ID on memblock regions > * @base: base of area to set node ID for > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index c19f5ac..2a967f7 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -5483,8 +5483,17 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, > if (context != MEMMAP_EARLY) > goto not_early; > > - if (!early_pfn_valid(pfn)) > + if (!early_pfn_valid(pfn)) { > +#if (defined CONFIG_HAVE_MEMBLOCK) && (defined CONFIG_HAVE_ARCH_PFN_VALID) > + /* > + * Skip to the pfn preceding the next valid one (or > + * end_pfn), such that we hit a valid pfn (or end_pfn) > + * on our next iteration of the loop. > + */ > + pfn = memblock_next_valid_pfn(pfn) - 1; > +#endif > continue; > + } > if (!early_pfn_in_nid(pfn, nid)) > continue; > if (!update_defer_init(pgdat, pfn, end_pfn, &nr_initialised)) > -- > 2.7.4 >