Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757191AbcJXEnD (ORCPT ); Mon, 24 Oct 2016 00:43:03 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:54081 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757091AbcJXEmz (ORCPT ); Mon, 24 Oct 2016 00:42:55 -0400 From: Anshuman Khandual To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: mhocko@suse.com, js1304@gmail.com, vbabka@suse.cz, mgorman@suse.de, minchan@kernel.org, akpm@linux-foundation.org, aneesh.kumar@linux.vnet.ibm.com, bsingharora@gmail.com Subject: [DEBUG 07/10] mm: Add debugfs interface to dump each node's zonelist information Date: Mon, 24 Oct 2016 10:12:26 +0530 X-Mailer: git-send-email 2.1.0 In-Reply-To: <1477284149-2976-1-git-send-email-khandual@linux.vnet.ibm.com> References: <1477283517-2504-1-git-send-email-khandual@linux.vnet.ibm.com> <1477284149-2976-1-git-send-email-khandual@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16102404-0016-0000-0000-000001E23F7F X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16102404-0017-0000-0000-000005B11E0D Message-Id: <1477284149-2976-8-git-send-email-khandual@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-10-23_18:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1609300000 definitions=main-1610240083 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3840 Lines: 140 Each individual node in the system has a ZONELIST_FALLBACK zonelist and a ZONELIST_NOFALLBACK zonelist. These zonelists decide fallback order of zones during memory allocations. Sometimes it helps to dump these zonelists to see the priority order of various zones in them. Particularly platforms which support memory hotplug into previously non existing zones (at boot), this interface helps in visualizing which all zonelists of the system at what priority level, the new hot added memory ends up in. POWER is such a platform where all the memory detected during boot time remains with ZONE_DMA for good but then hot plug process can actually get new memory into ZONE_MOVABLE. So having a way to get the snapshot of the zonelists on the system after memory or node hot[un]plug is desirable. This change adds one new debugfs interface (/sys/kernel/debug/zonelists) which will fetch and dump this information. Example zonelist information from a KVM guest with four NUMA nodes on a POWER8 platform. [NODE (0)] ZONELIST_FALLBACK (0) (Node 0) (DMA) (1) (Node 1) (DMA) (2) (Node 2) (DMA) (3) (Node 3) (DMA) ZONELIST_NOFALLBACK (0) (Node 0) (DMA) [NODE (1)] ZONELIST_FALLBACK (0) (Node 1) (DMA) (1) (Node 2) (DMA) (2) (Node 3) (DMA) (3) (Node 0) (DMA) ZONELIST_NOFALLBACK (0) (Node 1) (DMA) [NODE (2)] ZONELIST_FALLBACK (0) (Node 2) (DMA) (1) (Node 3) (DMA) (2) (Node 0) (DMA) (3) (Node 1) (DMA) ZONELIST_NOFALLBACK (0) (Node 2) (DMA) [NODE (3)] ZONELIST_FALLBACK (0) (Node 3) (DMA) (1) (Node 0) (DMA) (2) (Node 1) (DMA) (3) (Node 2) (DMA) ZONELIST_NOFALLBACK (0) (Node 3) (DMA) Signed-off-by: Anshuman Khandual --- mm/memory.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) diff --git a/mm/memory.c b/mm/memory.c index e18c57b..3be1753 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -64,6 +64,7 @@ #include #include #include +#include #include #include @@ -3087,6 +3088,68 @@ static int __init fault_around_debugfs(void) pr_warn("Failed to create fault_around_bytes in debugfs"); return 0; } + +#ifdef CONFIG_NUMA +static void show_zonelist(struct seq_file *m, struct zonelist *zonelist) +{ + unsigned int i; + + for (i = 0; zonelist->_zonerefs[i].zone; i++) { + seq_printf(m, "\t\t(%d) (Node %d) (%-7s 0x%pK)\n", i, + zonelist->_zonerefs[i].zone->zone_pgdat->node_id, + zone_names[zonelist->_zonerefs[i].zone_idx], + (void *) zonelist->_zonerefs[i].zone); + } +} + +static int zonelists_show(struct seq_file *m, void *v) +{ + struct zonelist *zonelist; + unsigned int node; + + for_each_online_node(node) { + zonelist = &(NODE_DATA(node)-> + node_zonelists[ZONELIST_FALLBACK]); + seq_printf(m, "[NODE (%d)]\n", node); + seq_puts(m, "\tZONELIST_FALLBACK "); + seq_printf(m, "(0x%pK)\n", zonelist); + show_zonelist(m, zonelist); + + zonelist = &(NODE_DATA(node)-> + node_zonelists[ZONELIST_NOFALLBACK]); + seq_puts(m, "\tZONELIST_NOFALLBACK "); + seq_printf(m, "(0x%pK)\n", zonelist); + show_zonelist(m, zonelist); + } + return 0; +} + +static int zonelists_open(struct inode *inode, struct file *filp) +{ + return single_open(filp, zonelists_show, NULL); +} + +static const struct file_operations zonelists_fops = { + .open = zonelists_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static int __init zonelists_debugfs(void) +{ + void *ret; + + ret = debugfs_create_file("zonelists", 0444, NULL, NULL, + &zonelists_fops); + if (!ret) + pr_warn("Failed to create zonelists in debugfs"); + return 0; +} + +late_initcall(zonelists_debugfs); +#endif /* CONFIG_NUMA */ + late_initcall(fault_around_debugfs); #endif -- 2.1.0