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author | Dave Hansen <dave.hansen@linux.intel.com> | 2019-02-25 10:57:33 -0800 |
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committer | Dan Williams <dan.j.williams@intel.com> | 2019-02-28 10:41:23 -0800 |
commit | b926b7f3baecb2a855db629e6822e1a85212e91c (patch) | |
tree | 617f873b72fc87d2cbbac2d267b570abc30ddf58 /mm | |
parent | 5cd401ace914dc68556c6d2fcae0c349444d5f86 (diff) | |
download | linux-b926b7f3baecb2a855db629e6822e1a85212e91c.tar.gz |
mm/resource: Move HMM pr_debug() deeper into resource code
HMM consumes physical address space for its own use, even though nothing is mapped or accessible there. It uses a special resource description (IORES_DESC_DEVICE_PRIVATE_MEMORY) to uniquely identify these areas. When HMM consumes address space, it makes a best guess about what to consume. However, it is possible that a future memory or device hotplug can collide with the reserved area. In the case of these conflicts, there is an error message in register_memory_resource(). Later patches in this series move register_memory_resource() from using request_resource_conflict() to __request_region(). Unfortunately, __request_region() does not return the conflict like the previous function did, which makes it impossible to check for IORES_DESC_DEVICE_PRIVATE_MEMORY in a conflicting resource. Instead of warning in register_memory_resource(), move the check into the core resource code itself (__request_region()) where the conflicting resource _is_ available. This has the added bonus of producing a warning in case of HMM conflicts with devices *or* RAM address space, as opposed to the RAM- only warnings that were there previously. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Jerome Glisse <jglisse@redhat.com> 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> Cc: Keith Busch <keith.busch@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/memory_hotplug.c | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index b9a667d36c55..e198974c968d 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -110,11 +110,6 @@ static struct resource *register_memory_resource(u64 start, u64 size) res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; conflict = request_resource_conflict(&iomem_resource, res); if (conflict) { - if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) { - pr_debug("Device unaddressable memory block " - "memory hotplug at %#010llx !\n", - (unsigned long long)start); - } pr_debug("System RAM resource %pR cannot be added\n", res); kfree(res); return ERR_PTR(-EEXIST); |