From mboxrd@z Thu Jan 1 00:00:00 1970 From: Baoquan He Subject: Re: [PATCH 17/21] mm: free_area_init: allow defining max_zone_pfn in descending order Date: Thu, 23 Apr 2020 10:57:20 +0800 Message-ID: <20200423025720.GA4247@MiWiFi-R3L-srv> References: <20200412194859.12663-1-rppt@kernel.org> <20200412194859.12663-18-rppt@kernel.org> <20200423025311.GZ4247@MiWiFi-R3L-srv> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20200423025311.GZ4247@MiWiFi-R3L-srv> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+glpr-linux-riscv=m.gmane-mx.org@lists.infradead.org To: Mike Rapoport Cc: Rich Felker , linux-ia64@vger.kernel.org, linux-doc@vger.kernel.org, Catalin Marinas , Heiko Carstens , Michal Hocko , "James E.J. Bottomley" , Max Filippov , Guo Ren , linux-csky@vger.kernel.org, linux-parisc@vger.kernel.org, sparclinux@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-riscv@lists.infradead.org, Greg Ungerer , linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-c6x-dev@linux-c6x.org, Brian Cain , Jonathan Corbet , linux-sh@vger.kernel.org, Michael Ellerman , Helge Deller , x86@kernel.org, Russell King , Ley Foon Tan List-Id: linux-arch.vger.kernel.org On 04/23/20 at 10:53am, Baoquan He wrote: > On 04/12/20 at 10:48pm, Mike Rapoport wrote: > > From: Mike Rapoport > > > > Some architectures (e.g. ARC) have the ZONE_HIGHMEM zone below the > > ZONE_NORMAL. Allowing free_area_init() parse max_zone_pfn array even it is > > sorted in descending order allows using free_area_init() on such > > architectures. > > > > Add top -> down traversal of max_zone_pfn array in free_area_init() and use > > the latter in ARC node/zone initialization. > > Or maybe leave ARC as is. The change in this patchset doesn't impact > ARC's handling about zone initialization, leaving it as is can reduce > the complication in implementation of free_area_init(), which is a > common function. So I personally don't see a strong motivation to have > this patch. OK, seems this patch is prepared to simplify free_area_init_node(), so take back what I said at above. Then this looks necessary, even though it introduces special case into common function free_area_init(). Reviewed-by: Baoquan He > > > > > Signed-off-by: Mike Rapoport > > --- > > arch/arc/mm/init.c | 36 +++++++----------------------------- > > mm/page_alloc.c | 24 +++++++++++++++++++----- > > 2 files changed, 26 insertions(+), 34 deletions(-) > > > > diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c > > index 0920c969c466..41eb9be1653c 100644 > > --- a/arch/arc/mm/init.c > > +++ b/arch/arc/mm/init.c > > @@ -63,11 +63,13 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size) > > > > low_mem_sz = size; > > in_use = 1; > > + memblock_add_node(base, size, 0); > > } else { > > #ifdef CONFIG_HIGHMEM > > high_mem_start = base; > > high_mem_sz = size; > > in_use = 1; > > + memblock_add_node(base, size, 1); > > #endif > > } > > > > @@ -83,8 +85,7 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size) > > */ > > void __init setup_arch_memory(void) > > { > > - unsigned long zones_size[MAX_NR_ZONES]; > > - unsigned long zones_holes[MAX_NR_ZONES]; > > + unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 }; > > > > init_mm.start_code = (unsigned long)_text; > > init_mm.end_code = (unsigned long)_etext; > > @@ -115,7 +116,6 @@ void __init setup_arch_memory(void) > > * the crash > > */ > > > > - memblock_add_node(low_mem_start, low_mem_sz, 0); > > memblock_reserve(CONFIG_LINUX_LINK_BASE, > > __pa(_end) - CONFIG_LINUX_LINK_BASE); > > > > @@ -133,22 +133,7 @@ void __init setup_arch_memory(void) > > memblock_dump_all(); > > > > /*----------------- node/zones setup --------------------------*/ > > - memset(zones_size, 0, sizeof(zones_size)); > > - memset(zones_holes, 0, sizeof(zones_holes)); > > - > > - zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn; > > - zones_holes[ZONE_NORMAL] = 0; > > - > > - /* > > - * We can't use the helper free_area_init(zones[]) because it uses > > - * PAGE_OFFSET to compute the @min_low_pfn which would be wrong > > - * when our kernel doesn't start at PAGE_OFFSET, i.e. > > - * PAGE_OFFSET != CONFIG_LINUX_RAM_BASE > > - */ > > - free_area_init_node(0, /* node-id */ > > - zones_size, /* num pages per zone */ > > - min_low_pfn, /* first pfn of node */ > > - zones_holes); /* holes */ > > + max_zone_pfn[ZONE_NORMAL] = max_low_pfn; > > > > #ifdef CONFIG_HIGHMEM > > /* > > @@ -168,20 +153,13 @@ void __init setup_arch_memory(void) > > min_high_pfn = PFN_DOWN(high_mem_start); > > max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz); > > > > - zones_size[ZONE_NORMAL] = 0; > > - zones_holes[ZONE_NORMAL] = 0; > > - > > - zones_size[ZONE_HIGHMEM] = max_high_pfn - min_high_pfn; > > - zones_holes[ZONE_HIGHMEM] = 0; > > - > > - free_area_init_node(1, /* node-id */ > > - zones_size, /* num pages per zone */ > > - min_high_pfn, /* first pfn of node */ > > - zones_holes); /* holes */ > > + max_zone_pfn[ZONE_HIGHMEM] = max_high_pfn; > > > > high_memory = (void *)(min_high_pfn << PAGE_SHIFT); > > kmap_init(); > > #endif > > + > > + free_area_init(max_zone_pfn); > > } > > > > /* > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > > index 343d87b8697d..376434c7a78b 100644 > > --- a/mm/page_alloc.c > > +++ b/mm/page_alloc.c > > @@ -7429,7 +7429,8 @@ static void check_for_memory(pg_data_t *pgdat, int nid) > > void __init free_area_init(unsigned long *max_zone_pfn) > > { > > unsigned long start_pfn, end_pfn; > > - int i, nid; > > + int i, nid, zone; > > + bool descending = false; > > > > /* Record where the zone boundaries are */ > > memset(arch_zone_lowest_possible_pfn, 0, > > @@ -7439,13 +7440,26 @@ void __init free_area_init(unsigned long *max_zone_pfn) > > > > start_pfn = find_min_pfn_with_active_regions(); > > > > + /* > > + * Some architecturs, e.g. ARC may have ZONE_HIGHMEM below > > + * ZONE_NORMAL. For such cases we allow max_zone_pfn sorted in the > > + * descending order > > + */ > > + if (MAX_NR_ZONES > 1 && max_zone_pfn[0] > max_zone_pfn[1]) > > + descending = true; > > + > > for (i = 0; i < MAX_NR_ZONES; i++) { > > - if (i == ZONE_MOVABLE) > > + if (descending) > > + zone = MAX_NR_ZONES - i - 1; > > + else > > + zone = i; > > + > > + if (zone == ZONE_MOVABLE) > > continue; > > > > - end_pfn = max(max_zone_pfn[i], start_pfn); > > - arch_zone_lowest_possible_pfn[i] = start_pfn; > > - arch_zone_highest_possible_pfn[i] = end_pfn; > > + end_pfn = max(max_zone_pfn[zone], start_pfn); > > + arch_zone_lowest_possible_pfn[zone] = start_pfn; > > + arch_zone_highest_possible_pfn[zone] = end_pfn; > > > > start_pfn = end_pfn; > > } > > -- > > 2.25.1 > >