Messages in this thread Patch in this message | | | Subject | [PATCH 3/4] dax/kmem: let walk_system_ram_range() search child resources | From | Dave Hansen <> | Date | Wed, 16 Jan 2019 10:19:04 -0800 |
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From: Dave Hansen <dave.hansen@linux.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 <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: linux-nvdimm@lists.01.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: Huang Ying <ying.huang@intel.com> Cc: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> ---
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 2018-12-20 11:48:42.824771932 -0800 +++ b/kernel/resource.c 2018-12-20 11:48:42.827771932 -0800 @@ -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) _
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