From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 17BC9C77B7F for ; Fri, 19 May 2023 07:34:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230193AbjESHeN (ORCPT ); Fri, 19 May 2023 03:34:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57632 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229436AbjESHeK (ORCPT ); Fri, 19 May 2023 03:34:10 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id ABA67122 for ; Fri, 19 May 2023 00:34:08 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 125491FB; Fri, 19 May 2023 00:34:53 -0700 (PDT) Received: from [192.168.0.11] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0DE623F73F; Fri, 19 May 2023 00:34:05 -0700 (PDT) Message-ID: <4995207f-cf18-634d-c3b2-43affa7482f9@arm.com> Date: Fri, 19 May 2023 13:04:02 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.10.0 Subject: Re: [PATCH v3] memblock: Add flags and nid info in memblock debugfs Content-Language: en-US To: Yuwei Guan Cc: rppt@kernel.org, akpm@linux-foundation.org, tsahu@linux.ibm.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20230518091431.299-1-ssawgyw@gmail.com> From: Anshuman Khandual In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/18/23 19:35, Yuwei Guan wrote: > Anshuman Khandual 于2023年5月18日周四 18:12写道： >> >> >> >> On 5/18/23 14:44, Yuwei Guan wrote: >>> Currently, the memblock debugfs can display the count of memblock_type and >>> the base and end of the reg. However, when memblock_mark_*() or >>> memblock_set_node() is executed on some range, the information in the >>> existing debugfs cannot make it clear why the address is not consecutive. >>> >>> For example, >>> cat /sys/kernel/debug/memblock/memory >>> 0: 0x0000000080000000..0x00000000901fffff >>> 1: 0x0000000090200000..0x00000000905fffff >>> 2: 0x0000000090600000..0x0000000092ffffff >>> 3: 0x0000000093000000..0x00000000973fffff >>> 4: 0x0000000097400000..0x00000000b71fffff >>> 5: 0x00000000c0000000..0x00000000dfffffff >>> 6: 0x00000000e2500000..0x00000000f87fffff >>> 7: 0x00000000f8800000..0x00000000fa7fffff >>> 8: 0x00000000fa800000..0x00000000fd3effff >>> 9: 0x00000000fd3f0000..0x00000000fd3fefff >>> 10: 0x00000000fd3ff000..0x00000000fd7fffff >>> 11: 0x00000000fd800000..0x00000000fd901fff >>> 12: 0x00000000fd902000..0x00000000fd909fff >>> 13: 0x00000000fd90a000..0x00000000fd90bfff >>> 14: 0x00000000fd90c000..0x00000000ffffffff >>> 15: 0x0000000880000000..0x0000000affffffff >>> >>> So we can add flags and nid to this debugfs. >>> >>> For example, >>> cat /sys/kernel/debug/memblock/memory >>> 0: 0x0000000080000000..0x00000000901fffff NONE 0 >>> 1: 0x0000000090200000..0x00000000905fffff NOMAP 0 >>> 2: 0x0000000090600000..0x0000000092ffffff NONE 0 >>> 3: 0x0000000093000000..0x00000000973fffff NOMAP 0 >>> 4: 0x0000000097400000..0x00000000b71fffff NONE 0 >>> 5: 0x00000000c0000000..0x00000000dfffffff NONE 0 >>> 6: 0x00000000e2500000..0x00000000f87fffff NONE 0 >>> 7: 0x00000000f8800000..0x00000000fa7fffff NOMAP 0 >>> 8: 0x00000000fa800000..0x00000000fd3effff NONE 0 >>> 9: 0x00000000fd3f0000..0x00000000fd3fefff NOMAP 0 >>> 10: 0x00000000fd3ff000..0x00000000fd7fffff NONE 0 >>> 11: 0x00000000fd800000..0x00000000fd901fff NOMAP 0 >>> 12: 0x00000000fd902000..0x00000000fd909fff NONE 0 >>> 13: 0x00000000fd90a000..0x00000000fd90bfff NOMAP 0 >>> 14: 0x00000000fd90c000..0x00000000ffffffff NONE 0 >>> 15: 0x0000000880000000..0x0000000affffffff NONE 0 >> >> Although, Mike had suggested to keep these flags print last, above >> format looks good as well. >> >>> >>> Signed-off-by: Yuwei Guan >>> --- >>> v3: >>> - show string value for each memblock flag >>> --- >>> mm/memblock.c | 12 +++++++++++- >>> 1 file changed, 11 insertions(+), 1 deletion(-) >>> >>> diff --git a/mm/memblock.c b/mm/memblock.c >>> index 511d4783dcf1..5fba53f98b2d 100644 >>> --- a/mm/memblock.c >>> +++ b/mm/memblock.c >>> @@ -2143,13 +2143,23 @@ static int memblock_debug_show(struct seq_file *m, void *private) >>> struct memblock_region *reg; >>> int i; >>> phys_addr_t end; >>> + static const char flagname[BITS_PER_LONG][8] = { >>> + [0 ... (BITS_PER_LONG-1)] = "?", >> >> Minor nit - >> >> Although checkpatch does not complain, should there be spaces between >> the operator and operands e.g (BITS_PER_LONG - 1). >> >>> + >>> + [ilog2(MEMBLOCK_HOTPLUG)] = "HOTPLUG", >>> + [ilog2(MEMBLOCK_MIRROR)] = "MIRROR", >>> + [ilog2(MEMBLOCK_NOMAP)] = "NOMAP", >>> + [ilog2(MEMBLOCK_DRIVER_MANAGED)] = "DRV_MNG", >>> + }; >> >> Also, BITS_PER_LONG sized array is really required here ? as there are >> just four available memblock flags. >> > Hi Anshuman, > The main reason to use BITS_PER_LONG is to reserve. > If the flagname buffer is (ilog2(MEMBLOCK_DRIVER_MANAGED) + 1), > memblock_flags adds a new attribute and does not add its name in debugfs, > it will cause an overflow. Agreed. > But BITS_PER_LONG is too wasteful, so I implement a new solution. > Please help to check it. > > struct memblock_type *type = m->private; > struct memblock_region *reg; > - int i; > + int i, j; > phys_addr_t end; > + static const char *flagname[] = { > + [ilog2(MEMBLOCK_HOTPLUG)] = "HOTPLUG", > + [ilog2(MEMBLOCK_MIRROR)] = "MIRROR", > + [ilog2(MEMBLOCK_NOMAP)] = "NOMAP", > + [ilog2(MEMBLOCK_DRIVER_MANAGED)] = "DRV_MNG", > + }; > > for (i = 0; i < type->cnt; i++) { > reg = &type->regions[i]; > end = reg->base + reg->size - 1; > > seq_printf(m, "%4d: ", i); > - seq_printf(m, "%pa..%pa\n", ®->base, &end); > + seq_printf(m, "%pa..%pa ", ®->base, &end); > + seq_printf(m, "%4d ", memblock_get_region_node(reg)); > + if (reg->flags) { > + for (j = 0; j < ARRAY_SIZE(flagname); j++) { > + if (reg->flags & (1U << j)) { > + seq_printf(m, "%s\n", flagname[j]); > + break; > + } > + } > + if (j == ARRAY_SIZE(flagname)) > + seq_printf(m, "%s\n", "UNKNOWN"); > + } else { > + seq_printf(m, "%s\n", "NONE"); > + } > } Please move the static array outside, just before this function and capture ARRAY_SIZE(flagname) in a local variable to make it compact. Rest looks good. >>> >>> for (i = 0; i < type->cnt; i++) { >>> reg = &type->regions[i]; >>> end = reg->base + reg->size - 1; >>> >>> seq_printf(m, "%4d: ", i); >>> - seq_printf(m, "%pa..%pa\n", ®->base, &end); >>> + seq_printf(m, "%pa..%pa ", ®->base, &end); >>> + seq_printf(m, "%8s ", reg->flags ? flagname[ilog2(reg->flags)] : "NONE"); >>> + seq_printf(m, "%4d\n", memblock_get_region_node(reg)); >>> } >>> return 0; >>> }