From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-f199.google.com (mail-pg1-f199.google.com [209.85.215.199]) by kanga.kvack.org (Postfix) with ESMTP id 760066B026A for ; Mon, 22 Oct 2018 16:18:50 -0400 (EDT) Received: by mail-pg1-f199.google.com with SMTP id x2-v6so30236805pgr.8 for ; Mon, 22 Oct 2018 13:18:50 -0700 (PDT) Received: from mga05.intel.com (mga05.intel.com. [192.55.52.43]) by mx.google.com with ESMTPS id g10-v6si32754692plt.212.2018.10.22.13.18.49 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 22 Oct 2018 13:18:49 -0700 (PDT) Subject: [PATCH 8/9] dax/kmem: let walk_system_ram_range() search child resources From: Dave Hansen Date: Mon, 22 Oct 2018 13:13:31 -0700 References: <20181022201317.8558C1D8@viggo.jf.intel.com> In-Reply-To: <20181022201317.8558C1D8@viggo.jf.intel.com> Message-Id: <20181022201331.8DDC3CDD@viggo.jf.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: Dave Hansen , dan.j.williams@intel.com, dave.jiang@intel.com, zwisler@kernel.org, vishal.l.verma@intel.com, thomas.lendacky@amd.com, akpm@linux-foundation.org, mhocko@suse.com, linux-nvdimm@lists.01.org, linux-mm@kvack.org, ying.huang@intel.com, fengguang.wu@intel.com In the process of onlining memory, we use walk_system_ram_range() to find the actual RAM areas inside of the area being onlined. However, it currently only finds memory resources which are "top-level" iomem_resources. Children are not currently searched which causes it to skip System RAM in areas like this (in the format of /proc/iomem): a0000000-bfffffff : Persistent Memory (legacy) a0000000-afffffff : System RAM Changing the true->false here allows children to be searched as well. We need this because we add a new "System RAM" resource underneath the "persistent memory" resource when we use persistent memory in a volatile mode. Cc: Dan Williams Cc: Dave Jiang Cc: Ross Zwisler Cc: Vishal Verma Cc: Tom Lendacky Cc: Andrew Morton Cc: Michal Hocko Cc: linux-nvdimm@lists.01.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: Huang Ying Cc: Fengguang Wu --- b/kernel/resource.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff -puN kernel/resource.c~mm-walk_system_ram_range-search-child-resources kernel/resource.c --- a/kernel/resource.c~mm-walk_system_ram_range-search-child-resources 2018-10-22 13:12:24.565930386 -0700 +++ b/kernel/resource.c 2018-10-22 13:12:24.572930386 -0700 @@ -445,6 +445,9 @@ int walk_mem_res(u64 start, u64 end, voi * This function calls the @func callback against all memory ranges of type * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY. * It is to be used only for System RAM. + * + * This will find System RAM ranges that are children of top-level resources + * in addition to top-level System RAM resources. */ int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, void *arg, int (*func)(unsigned long, unsigned long, void *)) @@ -460,7 +463,7 @@ int walk_system_ram_range(unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; while (start < end && !find_next_iomem_res(start, end, flags, IORES_DESC_NONE, - true, &res)) { + false, &res)) { pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT; end_pfn = (res.end + 1) >> PAGE_SHIFT; if (end_pfn > pfn) _