user/sven/linux.git/include/linux/node.h, branch v5.3.14

mm: make register_mem_sect_under_node() static

2019-07-19T00:08:06Z

It is only used internally. Link: http://lkml.kernel.org/r/20190614100114.311-4-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Andrew Morton Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Keith Busch Cc: Oscar Salvador Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/memory_hotplug: make unregister_memory_block_under_nodes() never fail

2019-07-19T00:08:06Z

We really don't want anything during memory hotunplug to fail. We always pass a valid memory block device, that check can go. Avoid allocating memory and eventually failing. As we are always called under lock, we can use a static piece of memory. This avoids having to put the structure onto the stack, having to guess about the stack size of callers. Patch inspired by a patch from Oscar Salvador. In the future, there might be no need to iterate over nodes at all. mem->nid should tell us exactly what to remove. Memory block devices with mixed nodes (added during boot) should properly fenced off and never removed. Link: http://lkml.kernel.org/r/20190527111152.16324-11-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Wei Yang Reviewed-by: Oscar Salvador Acked-by: Michal Hocko Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Alex Deucher Cc: "David S. Miller" Cc: Mark Brown Cc: Chris Wilson Cc: David Hildenbrand Cc: Jonathan Cameron Cc: Andrew Banman Cc: Andy Lutomirski Cc: Anshuman Khandual Cc: Ard Biesheuvel Cc: Arun KS Cc: Baoquan He Cc: Benjamin Herrenschmidt Cc: Borislav Petkov Cc: Catalin Marinas Cc: Chintan Pandya Cc: Christophe Leroy Cc: Dan Williams Cc: Dave Hansen Cc: Fenghua Yu Cc: Heiko Carstens Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Joonsoo Kim Cc: Jun Yao Cc: "Kirill A. Shutemov" Cc: Logan Gunthorpe Cc: Mark Rutland Cc: Masahiro Yamada Cc: Mathieu Malaterre Cc: Michael Ellerman Cc: Mike Rapoport Cc: "mike.travis@hpe.com" Cc: Nicholas Piggin Cc: Paul Mackerras Cc: Pavel Tatashin Cc: Peter Zijlstra Cc: Qian Cai Cc: Rich Felker Cc: Rob Herring Cc: Robin Murphy Cc: Thomas Gleixner Cc: Tony Luck Cc: Vasily Gorbik Cc: Will Deacon Cc: Yoshinori Sato Cc: Yu Zhao Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/memory_hotplug: remove memory block devices before arch_remove_memory()

2019-07-19T00:08:06Z

Let's factor out removing of memory block devices, which is only necessary for memory added via add_memory() and friends that created memory block devices. Remove the devices before calling arch_remove_memory(). This finishes factoring out memory block device handling from arch_add_memory() and arch_remove_memory(). Link: http://lkml.kernel.org/r/20190527111152.16324-10-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Dan Williams Acked-by: Michal Hocko Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: David Hildenbrand Cc: "mike.travis@hpe.com" Cc: Andrew Banman Cc: Ingo Molnar Cc: Alex Deucher Cc: "David S. Miller" Cc: Mark Brown Cc: Chris Wilson Cc: Oscar Salvador Cc: Jonathan Cameron Cc: Arun KS Cc: Mathieu Malaterre Cc: Andy Lutomirski Cc: Anshuman Khandual Cc: Ard Biesheuvel Cc: Baoquan He Cc: Benjamin Herrenschmidt Cc: Borislav Petkov Cc: Catalin Marinas Cc: Chintan Pandya Cc: Christophe Leroy Cc: Dave Hansen Cc: Fenghua Yu Cc: Heiko Carstens Cc: "H. Peter Anvin" Cc: Joonsoo Kim Cc: Jun Yao Cc: "Kirill A. Shutemov" Cc: Logan Gunthorpe Cc: Mark Rutland Cc: Masahiro Yamada Cc: Michael Ellerman Cc: Mike Rapoport Cc: Nicholas Piggin Cc: Oscar Salvador Cc: Paul Mackerras Cc: Pavel Tatashin Cc: Peter Zijlstra Cc: Qian Cai Cc: Rich Felker Cc: Rob Herring Cc: Robin Murphy Cc: Thomas Gleixner Cc: Tony Luck Cc: Vasily Gorbik Cc: Wei Yang Cc: Will Deacon Cc: Yoshinori Sato Cc: Yu Zhao Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

node: Add memory-side caching attributes

2019-04-04T16:41:21Z

System memory may have caches to help improve access speed to frequently requested address ranges. While the system provided cache is transparent to the software accessing these memory ranges, applications can optimize their own access based on cache attributes. Provide a new API for the kernel to register these memory-side caches under the memory node that provides it. The new sysfs representation is modeled from the existing cpu cacheinfo attributes, as seen from /sys/devices/system/cpu//cache/. Unlike CPU cacheinfo though, the node cache level is reported from the view of the memory. A higher level number is nearer to the CPU, while lower levels are closer to the last level memory. The exported attributes are the cache size, the line size, associativity indexing, and write back policy, and add the attributes for the system memory caches to sysfs stable documentation. Signed-off-by: Keith Busch Reviewed-by: Rafael J. Wysocki Reviewed-by: Brice Goglin Tested-by: Brice Goglin Signed-off-by: Greg Kroah-Hartman

node: Add heterogenous memory access attributes

2019-04-04T16:41:21Z

Heterogeneous memory systems provide memory nodes with different latency and bandwidth performance attributes. Provide a new kernel interface for subsystems to register the attributes under the memory target node's initiator access class. If the system provides this information, applications may query these attributes when deciding which node to request memory. The following example shows the new sysfs hierarchy for a node exporting performance attributes: # tree -P "read*|write*"/sys/devices/system/node/nodeY/accessZ/initiators/ /sys/devices/system/node/nodeY/accessZ/initiators/ |-- read_bandwidth |-- read_latency |-- write_bandwidth `-- write_latency The bandwidth is exported as MB/s and latency is reported in nanoseconds. The values are taken from the platform as reported by the manufacturer. Memory accesses from an initiator node that is not one of the memory's access "Z" initiator nodes linked in the same directory may observe different performance than reported here. When a subsystem makes use of this interface, initiators of a different access number may not have the same performance relative to initiators in other access numbers, or omitted from the any access class' initiators. Descriptions for memory access initiator performance access attributes are added to sysfs stable documentation. Acked-by: Jonathan Cameron Tested-by: Jonathan Cameron Signed-off-by: Keith Busch Reviewed-by: Rafael J. Wysocki Tested-by: Brice Goglin Signed-off-by: Greg Kroah-Hartman

node: Link memory nodes to their compute nodes

2019-04-04T16:41:20Z

Systems may be constructed with various specialized nodes. Some nodes may provide memory, some provide compute devices that access and use that memory, and others may provide both. Nodes that provide memory are referred to as memory targets, and nodes that can initiate memory access are referred to as memory initiators. Memory targets will often have varying access characteristics from different initiators, and platforms may have ways to express those relationships. In preparation for these systems, provide interfaces for the kernel to export the memory relationship among different nodes memory targets and their initiators with symlinks to each other. If a system provides access locality for each initiator-target pair, nodes may be grouped into ranked access classes relative to other nodes. The new interface allows a subsystem to register relationships of varying classes if available and desired to be exported. A memory initiator may have multiple memory targets in the same access class. The target memory's initiators in a given class indicate the nodes access characteristics share the same performance relative to other linked initiator nodes. Each target within an initiator's access class, though, do not necessarily perform the same as each other. A memory target node may have multiple memory initiators. All linked initiators in a target's class have the same access characteristics to that target. The following example show the nodes' new sysfs hierarchy for a memory target node 'Y' with access class 0 from initiator node 'X': # symlinks -v /sys/devices/system/node/nodeX/access0/ relative: /sys/devices/system/node/nodeX/access0/targets/nodeY -> ../../nodeY # symlinks -v /sys/devices/system/node/nodeY/access0/ relative: /sys/devices/system/node/nodeY/access0/initiators/nodeX -> ../../nodeX The new attributes are added to the sysfs stable documentation. Reviewed-by: Jonathan Cameron Signed-off-by: Keith Busch Reviewed-by: Rafael J. Wysocki Tested-by: Brice Goglin Signed-off-by: Greg Kroah-Hartman

mm/memory_hotplug.c: make register_mem_sect_under_node() a callback of walk_memory_range()

2018-08-17T23:20:29Z

link_mem_sections() and walk_memory_range() share most of the code, so we can use convert link_mem_sections() into a dummy function that calls walk_memory_range() with a callback to register_mem_sect_under_node(). This patch converts register_mem_sect_under_node() in order to match a walk_memory_range's callback, getting rid of the check_nid argument and checking instead if the system is still boothing, since we only have to check for the nid if the system is in such state. Link: http://lkml.kernel.org/r/20180622111839.10071-4-osalvador@techadventures.net Signed-off-by: Oscar Salvador Suggested-by: Pavel Tatashin Tested-by: Reza Arbab Tested-by: Jonathan Cameron Reviewed-by: Pavel Tatashin Cc: Michal Hocko Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/memory_hotplug: fix leftover use of struct page during hotplug

2018-05-26T01:12:11Z

The case of a new numa node got missed in avoiding using the node info from page_struct during hotplug. In this path we have a call to register_mem_sect_under_node (which allows us to specify it is hotplug so don't change the node), via link_mem_sections which unfortunately does not. Fix is to pass check_nid through link_mem_sections as well and disable it in the new numa node path. Note the bug only 'sometimes' manifests depending on what happens to be in the struct page structures - there are lots of them and it only needs to match one of them. The result of the bug is that (with a new memory only node) we never successfully call register_mem_sect_under_node so don't get the memory associated with the node in sysfs and meminfo for the node doesn't report it. It came up whilst testing some arm64 hotplug patches, but appears to be universal. Whilst I'm triggering it by removing then reinserting memory to a node with no other elements (thus making the node disappear then appear again), it appears it would happen on hotplugging memory where there was none before and it doesn't seem to be related the arm64 patches. These patches call __add_pages (where most of the issue was fixed by Pavel's patch). If there is a node at the time of the __add_pages call then all is well as it calls register_mem_sect_under_node from there with check_nid set to false. Without a node that function returns having not done the sysfs related stuff as there is no node to use. This is expected but it is the resulting path that fails... Exact path to the problem is as follows: mm/memory_hotplug.c: add_memory_resource() The node is not online so we enter the 'if (new_node)' twice, on the second such block there is a call to link_mem_sections which calls into drivers/node.c: link_mem_sections() which calls drivers/node.c: register_mem_sect_under_node() which calls get_nid_for_pfn and keeps trying until the output of that matches the expected node (passed all the way down from add_memory_resource) It is effectively the same fix as the one referred to in the fixes tag just in the code path for a new node where the comments point out we have to rerun the link creation because it will have failed in register_new_memory (as there was no node at the time). (actually that comment is wrong now as we don't have register_new_memory any more it got renamed to hotplug_memory_register in Pavel's patch). Link: http://lkml.kernel.org/r/20180504085311.1240-1-Jonathan.Cameron@huawei.com Fixes: fc44f7f9231a ("mm/memory_hotplug: don't read nid from struct page during hotplug") Signed-off-by: Jonathan Cameron Reviewed-by: Pavel Tatashin Acked-by: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/memory_hotplug: don't read nid from struct page during hotplug

2018-04-06T04:36:25Z

During memory hotplugging the probe routine will leave struct pages uninitialized, the same as it is currently done during boot. Therefore, we do not want to access the inside of struct pages before __init_single_page() is called during onlining. Because during hotplug we know that pages in one memory block belong to the same numa node, we can skip the checking. We should keep checking for the boot case. [pasha.tatashin@oracle.com: s/register_new_memory()/hotplug_memory_register()] Link: http://lkml.kernel.org/r/20180228030308.1116-6-pasha.tatashin@oracle.com Link: http://lkml.kernel.org/r/20180215165920.8570-6-pasha.tatashin@oracle.com Signed-off-by: Pavel Tatashin Acked-by: Michal Hocko Reviewed-by: Ingo Molnar Cc: Baoquan He Cc: Bharata B Rao Cc: Daniel Jordan Cc: Dan Williams Cc: Greg Kroah-Hartman Cc: "H. Peter Anvin" Cc: Kirill A. Shutemov Cc: Mel Gorman Cc: Steven Sistare Cc: Thomas Gleixner Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55Z

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman