Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753140AbbLID25 (ORCPT ); Tue, 8 Dec 2015 22:28:57 -0500 Received: from szxga03-in.huawei.com ([119.145.14.66]:33548 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751497AbbLID24 (ORCPT ); Tue, 8 Dec 2015 22:28:56 -0500 Message-ID: <56679FDC.1080800@huawei.com> Date: Wed, 9 Dec 2015 11:28:28 +0800 From: Xishi Qiu User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Taku Izumi CC: , , , , , , , Subject: Re: [PATCH v3 2/2] mm: Introduce kernelcore=mirror option References: <1449631109-14756-1-git-send-email-izumi.taku@jp.fujitsu.com> <1449631177-14863-1-git-send-email-izumi.taku@jp.fujitsu.com> In-Reply-To: <1449631177-14863-1-git-send-email-izumi.taku@jp.fujitsu.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.25.179] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020205.56679FE6.0158,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: b2b35bec5b8fcc2af76fc6409ea5a59c Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8903 Lines: 253 On 2015/12/9 11:19, Taku Izumi wrote: > This patch extends existing "kernelcore" option and > introduces kernelcore=mirror option. By specifying > "mirror" instead of specifying the amount of memory, > non-mirrored (non-reliable) region will be arranged > into ZONE_MOVABLE. > > v1 -> v2: > - Refine so that the following case also can be > handled properly: > > Node X: |MMMMMM------MMMMMM--------| > (legend) M: mirrored -: not mirrrored > > In this case, ZONE_NORMAL and ZONE_MOVABLE are > arranged like bellow: > > Node X: |MMMMMM------MMMMMM--------| > |ooooooxxxxxxooooooxxxxxxxx| ZONE_NORMAL > |ooooooxxxxxxoooooooo| ZONE_MOVABLE > (legend) o: present x: absent > > v2 -> v3: > - change the option name from kernelcore=reliable > into kernelcore=mirror > - documentation fix so that users can understand > nn[KMS] and mirror are exclusive > > Signed-off-by: Taku Izumi > --- > Documentation/kernel-parameters.txt | 11 +++- > mm/page_alloc.c | 110 ++++++++++++++++++++++++++++++++++-- > 2 files changed, 114 insertions(+), 7 deletions(-) > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > index f8aae63..b0ffc76 100644 > --- a/Documentation/kernel-parameters.txt > +++ b/Documentation/kernel-parameters.txt > @@ -1695,7 +1695,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > > keepinitrd [HW,ARM] > > - kernelcore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter > + kernelcore= Format: nn[KMG] | "mirror" > + [KNL,X86,IA-64,PPC] This parameter > specifies the amount of memory usable by the kernel > for non-movable allocations. The requested amount is > spread evenly throughout all nodes in the system. The > @@ -1711,6 +1712,14 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > use the HighMem zone if it exists, and the Normal > zone if it does not. > > + Instead of specifying the amount of memory (nn[KMS]), > + you can specify "mirror" option. In case "mirror" > + option is specified, mirrored (reliable) memory is used > + for non-movable allocations and remaining memory is used > + for Movable pages. nn[KMS] and "mirror" are exclusive, > + so you can NOT specify nn[KMG] and "mirror" at the same > + time. > + Hi Taku, How about add some comment, if mirrored memroy is too small, then the normal zone is small, so it may be oom. The mirrored memory is at least 1/64 of whole memory, because struct pages usually take 64 bytes per page. Thanks, Xishi Qiu > kgdbdbgp= [KGDB,HW] kgdb over EHCI usb debug port. > Format: [,poll interval] > The controller # is the number of the ehci usb debug > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index acb0b4e..4157476 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -251,6 +251,7 @@ static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES]; > static unsigned long __initdata required_kernelcore; > static unsigned long __initdata required_movablecore; > static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES]; > +static bool mirrored_kernelcore; > > /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */ > int movable_zone; > @@ -4472,6 +4473,7 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, > unsigned long pfn; > struct zone *z; > unsigned long nr_initialised = 0; > + struct memblock_region *r = NULL, *tmp; > > if (highest_memmap_pfn < end_pfn - 1) > highest_memmap_pfn = end_pfn - 1; > @@ -4491,6 +4493,38 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, > if (!update_defer_init(pgdat, pfn, end_pfn, > &nr_initialised)) > break; > + > + /* > + * if not mirrored_kernelcore and ZONE_MOVABLE exists, > + * range from zone_movable_pfn[nid] to end of each node > + * should be ZONE_MOVABLE not ZONE_NORMAL. skip it. > + */ > + if (!mirrored_kernelcore && zone_movable_pfn[nid]) > + if (zone == ZONE_NORMAL && > + pfn >= zone_movable_pfn[nid]) > + continue; > + > + /* > + * check given memblock attribute by firmware which > + * can affect kernel memory layout. > + * if zone==ZONE_MOVABLE but memory is mirrored, > + * it's an overlapped memmap init. skip it. > + */ > + if (mirrored_kernelcore && zone == ZONE_MOVABLE) { > + if (!r || > + pfn >= memblock_region_memory_end_pfn(r)) { > + for_each_memblock(memory, tmp) > + if (pfn < memblock_region_memory_end_pfn(tmp)) > + break; > + r = tmp; > + } > + if (pfn >= memblock_region_memory_base_pfn(r) && > + memblock_is_mirror(r)) { > + /* already initialized as NORMAL */ > + pfn = memblock_region_memory_end_pfn(r); > + continue; > + } > + } > } > > /* > @@ -4909,11 +4943,6 @@ static void __meminit adjust_zone_range_for_zone_movable(int nid, > *zone_end_pfn = min(node_end_pfn, > arch_zone_highest_possible_pfn[movable_zone]); > > - /* Adjust for ZONE_MOVABLE starting within this range */ > - } else if (*zone_start_pfn < zone_movable_pfn[nid] && > - *zone_end_pfn > zone_movable_pfn[nid]) { > - *zone_end_pfn = zone_movable_pfn[nid]; > - > /* Check if this whole range is within ZONE_MOVABLE */ > } else if (*zone_start_pfn >= zone_movable_pfn[nid]) > *zone_start_pfn = *zone_end_pfn; > @@ -4998,6 +5027,7 @@ static unsigned long __meminit zone_absent_pages_in_node(int nid, > unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type]; > unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type]; > unsigned long zone_start_pfn, zone_end_pfn; > + unsigned long nr_absent; > > /* When hotadd a new node from cpu_up(), the node should be empty */ > if (!node_start_pfn && !node_end_pfn) > @@ -5009,7 +5039,39 @@ static unsigned long __meminit zone_absent_pages_in_node(int nid, > adjust_zone_range_for_zone_movable(nid, zone_type, > node_start_pfn, node_end_pfn, > &zone_start_pfn, &zone_end_pfn); > - return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); > + nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); > + > + /* > + * ZONE_MOVABLE handling. > + * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages > + * and vice versa. > + */ > + if (zone_movable_pfn[nid]) { > + if (mirrored_kernelcore) { > + unsigned long start_pfn, end_pfn; > + struct memblock_region *r; > + > + for_each_memblock(memory, r) { > + start_pfn = clamp(memblock_region_memory_base_pfn(r), > + zone_start_pfn, zone_end_pfn); > + end_pfn = clamp(memblock_region_memory_end_pfn(r), > + zone_start_pfn, zone_end_pfn); > + > + if (zone_type == ZONE_MOVABLE && > + memblock_is_mirror(r)) > + nr_absent += end_pfn - start_pfn; > + > + if (zone_type == ZONE_NORMAL && > + !memblock_is_mirror(r)) > + nr_absent += end_pfn - start_pfn; > + } > + } else { > + if (zone_type == ZONE_NORMAL) > + nr_absent += node_end_pfn - zone_movable_pfn[nid]; > + } > + } > + > + return nr_absent; > } > > #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ > @@ -5507,6 +5569,36 @@ static void __init find_zone_movable_pfns_for_nodes(void) > } > > /* > + * If kernelcore=mirror is specified, ignore movablecore option > + */ > + if (mirrored_kernelcore) { > + bool mem_below_4gb_not_mirrored = false; > + > + for_each_memblock(memory, r) { > + if (memblock_is_mirror(r)) > + continue; > + > + nid = r->nid; > + > + usable_startpfn = memblock_region_memory_base_pfn(r); > + > + if (usable_startpfn < 0x100000) { > + mem_below_4gb_not_mirrored = true; > + continue; > + } > + > + zone_movable_pfn[nid] = zone_movable_pfn[nid] ? > + min(usable_startpfn, zone_movable_pfn[nid]) : > + usable_startpfn; > + } > + > + if (mem_below_4gb_not_mirrored) > + pr_warn("This configuration results in unmirrored kernel memory."); > + > + goto out2; > + } > + > + /* > * If movablecore=nn[KMG] was specified, calculate what size of > * kernelcore that corresponds so that memory usable for > * any allocation type is evenly spread. If both kernelcore > @@ -5766,6 +5858,12 @@ static int __init cmdline_parse_core(char *p, unsigned long *core) > */ > static int __init cmdline_parse_kernelcore(char *p) > { > + /* parse kernelcore=mirror */ > + if (parse_option_str(p, "mirror")) { > + mirrored_kernelcore = true; > + return 0; > + } > + > return cmdline_parse_core(p, &required_kernelcore); > } > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/