From 2b539aefe9e48e3908cff02699aa63a8b9bd268e Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Mon, 25 Feb 2019 10:57:38 -0800 Subject: [PATCH] mm/resource: Let walk_system_ram_range() search child resources 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. Signed-off-by: Dave Hansen Cc: Keith Busch 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 Cc: Borislav Petkov Cc: Bjorn Helgaas Cc: Yaowei Bai Cc: Takashi Iwai Cc: Jerome Glisse Signed-off-by: Dan Williams --- kernel/resource.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/resource.c b/kernel/resource.c index 35fe105d581e..e7f9d2a5db25 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -454,6 +454,9 @@ int walk_mem_res(u64 start, u64 end, void *arg, * 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 *)) @@ -469,7 +472,7 @@ int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, 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)