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34 Commits
| Author | SHA1 | Message | Date | |
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Huang Ying
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a530bbc538 |
memory tiers: use default_dram_perf_ref_source in log message
Commit |
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Linus Torvalds
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7856a56541 |
Many singleton patches - please see the various changelogs for details.
Quite a lot of nilfs2 work this time around.
Notable patch series in this pull request are:
"mul_u64_u64_div_u64: new implementation" by Nicolas Pitre, with
assistance from Uwe Kleine-König. Reimplement mul_u64_u64_div_u64() to
provide (much) more accurate results. The current implementation was
causing Uwe some issues in the PWM drivers.
"xz: Updates to license, filters, and compression options" from Lasse
Collin. Miscellaneous maintenance and kinor feature work to the xz
decompressor.
"Fix some GDB command error and add some GDB commands" from Kuan-Ying Lee.
Fixes and enhancements to the gdb scripts.
"treewide: add missing MODULE_DESCRIPTION() macros" from Jeff Johnson.
Adds lots of MODULE_DESCRIPTIONs, thus fixing lots of warnings about this.
"nilfs2: add support for some common ioctls" from Ryusuke Konishi. Adds
various commonly-available ioctls to nilfs2.
"This series fixes a number of formatting issues in kernel doc comments"
from Ryusuke Konishi does that.
"nilfs2: prevent unexpected ENOENT propagation" from Ryusuke Konishi. Fix
issues where -ENOENT was being unintentionally and inappropriately
returned to userspace.
"nilfs2: assorted cleanups" from Huang Xiaojia.
"nilfs2: fix potential issues with empty b-tree nodes" from Ryusuke
Konishi fixes some issues which can occur on corrupted nilfs2 filesystems.
"scripts/decode_stacktrace.sh: improve error reporting and usability" from
Luca Ceresoli does those things.
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Merge tag 'mm-nonmm-stable-2024-09-21-07-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
"Many singleton patches - please see the various changelogs for
details.
Quite a lot of nilfs2 work this time around.
Notable patch series in this pull request are:
- "mul_u64_u64_div_u64: new implementation" by Nicolas Pitre, with
assistance from Uwe Kleine-König. Reimplement mul_u64_u64_div_u64()
to provide (much) more accurate results. The current implementation
was causing Uwe some issues in the PWM drivers.
- "xz: Updates to license, filters, and compression options" from
Lasse Collin. Miscellaneous maintenance and kinor feature work to
the xz decompressor.
- "Fix some GDB command error and add some GDB commands" from
Kuan-Ying Lee. Fixes and enhancements to the gdb scripts.
- "treewide: add missing MODULE_DESCRIPTION() macros" from Jeff
Johnson. Adds lots of MODULE_DESCRIPTIONs, thus fixing lots of
warnings about this.
- "nilfs2: add support for some common ioctls" from Ryusuke Konishi.
Adds various commonly-available ioctls to nilfs2.
- "This series fixes a number of formatting issues in kernel doc
comments" from Ryusuke Konishi does that.
- "nilfs2: prevent unexpected ENOENT propagation" from Ryusuke
Konishi. Fix issues where -ENOENT was being unintentionally and
inappropriately returned to userspace.
- "nilfs2: assorted cleanups" from Huang Xiaojia.
- "nilfs2: fix potential issues with empty b-tree nodes" from Ryusuke
Konishi fixes some issues which can occur on corrupted nilfs2
filesystems.
- "scripts/decode_stacktrace.sh: improve error reporting and
usability" from Luca Ceresoli does those things"
* tag 'mm-nonmm-stable-2024-09-21-07-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (103 commits)
list: test: increase coverage of list_test_list_replace*()
list: test: fix tests for list_cut_position()
proc: use __auto_type more
treewide: correct the typo 'retun'
ocfs2: cleanup return value and mlog in ocfs2_global_read_info()
nilfs2: remove duplicate 'unlikely()' usage
nilfs2: fix potential oob read in nilfs_btree_check_delete()
nilfs2: determine empty node blocks as corrupted
nilfs2: fix potential null-ptr-deref in nilfs_btree_insert()
user_namespace: use kmemdup_array() instead of kmemdup() for multiple allocation
tools/mm: rm thp_swap_allocator_test when make clean
squashfs: fix percpu address space issues in decompressor_multi_percpu.c
lib: glob.c: added null check for character class
nilfs2: refactor nilfs_segctor_thread()
nilfs2: use kthread_create and kthread_stop for the log writer thread
nilfs2: remove sc_timer_task
nilfs2: do not repair reserved inode bitmap in nilfs_new_inode()
nilfs2: eliminate the shared counter and spinlock for i_generation
nilfs2: separate inode type information from i_state field
nilfs2: use the BITS_PER_LONG macro
...
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Yanfei Xu
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073c78edf5 |
memory tier: fix deadlock warning while onlining pages
commit |
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Hongbo Li
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01b58b1763 |
mm: make use of str_true_false helper
The helper str_true_false() was introduced to return "true/false" string literal. We can simplify this format by str_true_false. Link: https://lkml.kernel.org/r/20240827024517.914100-3-lihongbo22@huawei.com Signed-off-by: Hongbo Li <lihongbo22@huawei.com> Cc: Andy Shevchenko <andy@kernel.org> Cc: Anna Schumaker <anna@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Kees Cook <kees@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Trond Myklebust <trondmy@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Zi Yan
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2a28713a67 |
memory tiering: introduce folio_use_access_time() check
If memory tiering mode is on and a folio is not in the top tier memory, folio's cpupid field is repurposed to store page access time. Instead of an open coded check, use a function to encapsulate the check. Link: https://lkml.kernel.org/r/20240724130115.793641-3-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Ho-Ren (Jack) Chuang
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823430c8e9 |
memory tier: consolidate the initialization of memory tiers
The current memory tier initialization process is distributed across two different functions, memory_tier_init() and memory_tier_late_init(). This design is hard to maintain. Thus, this patch is proposed to reduce the possible code paths by consolidating different initialization patches into one. The earlier discussion with Jonathan and Ying is listed here: https://lore.kernel.org/lkml/20240405150244.00004b49@Huawei.com/ If we want to put these two initializations together, they must be placed together in the later function. Because only at that time, the HMAT information will be ready, adist between nodes can be calculated, and memory tiering can be established based on the adist. So we position the initialization at memory_tier_init() to the memory_tier_late_init() call. Moreover, it's natural to keep memory_tier initialization in drivers at device_initcall() level. If we simply move the set_node_memory_tier() from memory_tier_init() to late_initcall(), it will result in HMAT not registering the mt_adistance_algorithm callback function, because set_node_memory_tier() is not performed during the memory tiering initialization phase, leading to a lack of correct default_dram information. Therefore, we introduced a nodemask to pass the information of the default DRAM nodes. The reason for not choosing to reuse default_dram_type->nodes is that it is not clean enough. So in the end, we use a __initdata variable, which is a variable that is released once initialization is complete, including both CPU and memory nodes for HMAT to iterate through. Link: https://lkml.kernel.org/r/20240704072646.437579-1-horen.chuang@linux.dev Signed-off-by: Ho-Ren (Jack) Chuang <horenchuang@bytedance.com> Suggested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Gregory Price <gourry.memverge@gmail.com> Cc: Len Brown <lenb@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Ravi Jonnalagadda <ravis.opensrc@micron.com> Cc: SeongJae Park <sj@kernel.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Ho-Ren (Jack) Chuang
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cf93be18fa |
memory tier: create CPUless memory tiers after obtaining HMAT info
The current implementation treats emulated memory devices, such as CXL1.1 type3 memory, as normal DRAM when they are emulated as normal memory (E820_TYPE_RAM). However, these emulated devices have different characteristics than traditional DRAM, making it important to distinguish them. Thus, we modify the tiered memory initialization process to introduce a delay specifically for CPUless NUMA nodes. This delay ensures that the memory tier initialization for these nodes is deferred until HMAT information is obtained during the boot process. Finally, demotion tables are recalculated at the end. * late_initcall(memory_tier_late_init); Some device drivers may have initialized memory tiers between `memory_tier_init()` and `memory_tier_late_init()`, potentially bringing online memory nodes and configuring memory tiers. They should be excluded in the late init. * Handle cases where there is no HMAT when creating memory tiers There is a scenario where a CPUless node does not provide HMAT information. If no HMAT is specified, it falls back to using the default DRAM tier. * Introduce another new lock `default_dram_perf_lock` for adist calculation In the current implementation, iterating through CPUlist nodes requires holding the `memory_tier_lock`. However, `mt_calc_adistance()` will end up trying to acquire the same lock, leading to a potential deadlock. Therefore, we propose introducing a standalone `default_dram_perf_lock` to protect `default_dram_perf_*`. This approach not only avoids deadlock but also prevents holding a large lock simultaneously. * Upgrade `set_node_memory_tier` to support additional cases, including default DRAM, late CPUless, and hot-plugged initializations. To cover hot-plugged memory nodes, `mt_calc_adistance()` and `mt_find_alloc_memory_type()` are moved into `set_node_memory_tier()` to handle cases where memtype is not initialized and where HMAT information is available. * Introduce `default_memory_types` for those memory types that are not initialized by device drivers. Because late initialized memory and default DRAM memory need to be managed, a default memory type is created for storing all memory types that are not initialized by device drivers and as a fallback. Link: https://lkml.kernel.org/r/20240405000707.2670063-3-horenchuang@bytedance.com Signed-off-by: Ho-Ren (Jack) Chuang <horenchuang@bytedance.com> Signed-off-by: Hao Xiang <hao.xiang@bytedance.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Gregory Price <gourry.memverge@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Ravi Jonnalagadda <ravis.opensrc@micron.com> Cc: SeongJae Park <sj@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawie.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Ho-Ren (Jack) Chuang
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a72a30af55 |
memory tier: dax/kmem: introduce an abstract layer for finding, allocating, and putting memory types
Patch series "Improved Memory Tier Creation for CPUless NUMA Nodes", v11. When a memory device, such as CXL1.1 type3 memory, is emulated as normal memory (E820_TYPE_RAM), the memory device is indistinguishable from normal DRAM in terms of memory tiering with the current implementation. The current memory tiering assigns all detected normal memory nodes to the same DRAM tier. This results in normal memory devices with different attributions being unable to be assigned to the correct memory tier, leading to the inability to migrate pages between different types of memory. https://lore.kernel.org/linux-mm/PH0PR08MB7955E9F08CCB64F23963B5C3A860A@PH0PR08MB7955.namprd08.prod.outlook.com/T/ This patchset automatically resolves the issues. It delays the initialization of memory tiers for CPUless NUMA nodes until they obtain HMAT information and after all devices are initialized at boot time, eliminating the need for user intervention. If no HMAT is specified, it falls back to using `default_dram_type`. Example usecase: We have CXL memory on the host, and we create VMs with a new system memory device backed by host CXL memory. We inject CXL memory performance attributes through QEMU, and the guest now sees memory nodes with performance attributes in HMAT. With this change, we enable the guest kernel to construct the correct memory tiering for the memory nodes. This patch (of 2): Since different memory devices require finding, allocating, and putting memory types, these common steps are abstracted in this patch, enhancing the scalability and conciseness of the code. Link: https://lkml.kernel.org/r/20240405000707.2670063-1-horenchuang@bytedance.com Link: https://lkml.kernel.org/r/20240405000707.2670063-2-horenchuang@bytedance.com Signed-off-by: Ho-Ren (Jack) Chuang <horenchuang@bytedance.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawie.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Gregory Price <gourry.memverge@gmail.com> Cc: Hao Xiang <hao.xiang@bytedance.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Ravi Jonnalagadda <ravis.opensrc@micron.com> Cc: SeongJae Park <sj@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Li Zhijian
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601e793a74 |
mm/demotion: print demotion targets
Currently, when a demotion occurs, it will prioritize selecting a node from the preferred targets as the destination node for the demotion. If the preferred node does not meet the requirements, it will try from all the lower memory tier nodes until it finds a suitable demotion destination node or ultimately fails. However, the demotion target information isn't exposed to the users, especially the preferred target information, which relies on more factors. This makes it hard for users to understand the exact demotion behavior. Rather than having a new sysfs interface to expose this information, printing directly to kernel messages, just like the current page allocation fallback order does. A dmesg example with this patch is as follows: [ 0.704860] Demotion targets for Node 0: null [ 0.705456] Demotion targets for Node 1: null // node 2 is onlined [ 32.259775] Demotion targets for Node 0: perferred: 2, fallback: 2 [ 32.261290] Demotion targets for Node 1: perferred: 2, fallback: 2 [ 32.262726] Demotion targets for Node 2: null // node 3 is onlined [ 42.448809] Demotion targets for Node 0: perferred: 2, fallback: 2-3 [ 42.450704] Demotion targets for Node 1: perferred: 2, fallback: 2-3 [ 42.452556] Demotion targets for Node 2: perferred: 3, fallback: 3 [ 42.454136] Demotion targets for Node 3: null // node 4 is onlined [ 52.676833] Demotion targets for Node 0: perferred: 2, fallback: 2-4 [ 52.678735] Demotion targets for Node 1: perferred: 2, fallback: 2-4 [ 52.680493] Demotion targets for Node 2: perferred: 4, fallback: 3-4 [ 52.682154] Demotion targets for Node 3: null [ 52.683405] Demotion targets for Node 4: null // node 5 is onlined [ 62.931902] Demotion targets for Node 0: perferred: 2, fallback: 2-5 [ 62.938266] Demotion targets for Node 1: perferred: 5, fallback: 2-5 [ 62.943515] Demotion targets for Node 2: perferred: 4, fallback: 3-4 [ 62.947471] Demotion targets for Node 3: null [ 62.949908] Demotion targets for Node 4: null [ 62.952137] Demotion targets for Node 5: perferred: 3, fallback: 3-4 Regarding this requirement, we have previously discussed [1]. The initial proposal involved introducing a new sysfs interface. However, due to concerns about potential changes and compatibility issues with the interface in the future, a consensus was not reached with the community. Therefore, this time, we are directly printing out the information. [1] https://lore.kernel.org/all/d1d5add8-8f4a-4578-8bf0-2cbe79b09989@fujitsu.com/ Link: https://lkml.kernel.org/r/20240206020151.605516-1-lizhijian@fujitsu.com Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Ricardo B. Marliere
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e374ae2be2 |
memory tier: make memory_tier_subsys const
Now that the driver core can properly handle constant struct bus_type, move the memory_tier_subsys variable to be a constant structure as well, placing it into read-only memory which can not be modified at runtime. Link: https://lkml.kernel.org/r/20240204-bus_cleanup-mm-v1-1-00f49286f164@marliere.net Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Dave Jiang
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6a954e94d0 |
base/node / acpi: Change 'node_hmem_attrs' to 'access_coordinates'
Dan Williams suggested changing the struct 'node_hmem_attrs' to 'access_coordinates' [1]. The struct is a container of r/w-latency and r/w-bandwidth numbers. Moving forward, this container will also be used by CXL to store the performance characteristics of each link hop in the PCIE/CXL topology. So, where node_hmem_attrs is just the access parameters of a memory-node, access_coordinates applies more broadly to hardware topology characteristics. The observation is that seemed like an exercise in having the application identify "where" it falls on a spectrum of bandwidth and latency needs. For the tuple of read/write-latency and read/write-bandwidth, "coordinates" is not a perfect fit. Sometimes it is just conveying values in isolation and not a "location" relative to other performance points, but in the end this data is used to identify the performance operation point of a given memory-node. [2] Link: http://lore.kernel.org/r/64471313421f7_1b66294d5@dwillia2-xfh.jf.intel.com.notmuch/ Link: https://lore.kernel.org/linux-cxl/645e6215ee0de_1e6f2945e@dwillia2-xfh.jf.intel.com.notmuch/ Suggested-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/170319615734.2212653.15319394025985499185.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com> |
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Huang Ying
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6bc2cfdf82 |
dax, kmem: calculate abstract distance with general interface
Previously, a fixed abstract distance MEMTIER_DEFAULT_DAX_ADISTANCE is used for slow memory type in kmem driver. This limits the usage of kmem driver, for example, it cannot be used for HBM (high bandwidth memory). So, we use the general abstract distance calculation mechanism in kmem drivers to get more accurate abstract distance on systems with proper support. The original MEMTIER_DEFAULT_DAX_ADISTANCE is used as fallback only. Now, multiple memory types may be managed by kmem. These memory types are put into the "kmem_memory_types" list and protected by kmem_memory_type_lock. Link: https://lkml.kernel.org/r/20230926060628.265989-5-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Tested-by: Bharata B Rao <bharata@amd.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Alistair Popple <apopple@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Wei Xu <weixugc@google.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Rafael J Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Huang Ying
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3718c02dbd |
acpi, hmat: calculate abstract distance with HMAT
A memory tiering abstract distance calculation algorithm based on ACPI HMAT is implemented. The basic idea is as follows. The performance attributes of system default DRAM nodes are recorded as the base line. Whose abstract distance is MEMTIER_ADISTANCE_DRAM. Then, the ratio of the abstract distance of a memory node (target) to MEMTIER_ADISTANCE_DRAM is scaled based on the ratio of the performance attributes of the node to that of the default DRAM nodes. The functions to record the read/write latency/bandwidth of the default DRAM nodes and calculate abstract distance according to read/write latency/bandwidth ratio will be used by CXL CDAT (Coherent Device Attribute Table) and other memory device drivers. So, they are put in memory-tiers.c. Link: https://lkml.kernel.org/r/20230926060628.265989-4-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Tested-by: Bharata B Rao <bharata@amd.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Alistair Popple <apopple@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Wei Xu <weixugc@google.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Rafael J Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Huang Ying
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07a8bdd412 |
memory tiering: add abstract distance calculation algorithms management
Patch series "memory tiering: calculate abstract distance based on ACPI HMAT", v4. We have the explicit memory tiers framework to manage systems with multiple types of memory, e.g., DRAM in DIMM slots and CXL memory devices. Where, same kind of memory devices will be grouped into memory types, then put into memory tiers. To describe the performance of a memory type, abstract distance is defined. Which is in direct proportion to the memory latency and inversely proportional to the memory bandwidth. To keep the code as simple as possible, fixed abstract distance is used in dax/kmem to describe slow memory such as Optane DCPMM. To support more memory types, in this series, we added the abstract distance calculation algorithm management mechanism, provided a algorithm implementation based on ACPI HMAT, and used the general abstract distance calculation interface in dax/kmem driver. So, dax/kmem can support HBM (high bandwidth memory) in addition to the original Optane DCPMM. This patch (of 4): The abstract distance may be calculated by various drivers, such as ACPI HMAT, CXL CDAT, etc. While it may be used by various code which hot-add memory node, such as dax/kmem etc. To decouple the algorithm users and the providers, the abstract distance calculation algorithms management mechanism is implemented in this patch. It provides interface for the providers to register the implementation, and interface for the users. Multiple algorithm implementations can cooperate via calculating abstract distance for different memory nodes. The preference of algorithm implementations can be specified via priority (notifier_block.priority). Link: https://lkml.kernel.org/r/20230926060628.265989-1-ying.huang@intel.com Link: https://lkml.kernel.org/r/20230926060628.265989-2-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Tested-by: Bharata B Rao <bharata@amd.com> Reviewed-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Wei Xu <weixugc@google.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Rafael J Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Li Zhijian
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51a23b1be9 |
acpi,mm: fix typo sibiling -> sibling
First found this typo as reviewing memory tier code. Fix it by sed like: $ sed -i 's/sibiling/sibling/g' $(git grep -l sibiling) so the acpi one will be corrected as well. Link: https://lkml.kernel.org/r/20230802092856.819328-1-lizhijian@cn.fujitsu.com Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Len Brown <lenb@kernel.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Miaohe Lin
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8d3a7d797c |
memory tier: use helper macro __ATTR_RW()
Use helper macro __ATTR_RW to define numa demotion attributes. Minor readability improvement. Link: https://lkml.kernel.org/r/20230715035111.2656784-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Miaohe Lin
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bded67f81e |
memory tier: rename destroy_memory_type() to put_memory_type()
It appears that destroy_memory_type() isn't a very good name because we usually will not free the memory_type here. So rename it to a more appropriate name i.e. put_memory_type(). Link: https://lkml.kernel.org/r/20230706063905.543800-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Suggested-by: Huang, Ying <ying.huang@intel.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Xiao Yang <yangx.jy@fujitsu.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Miaohe Lin
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f58d7907a3 |
memory tier: use helper function destroy_memory_type()
Use helper function destroy_memory_type() to release memtype instead of open code it to help improve code readability a bit. No functional change intended. Link: https://lkml.kernel.org/r/20230626121053.1916447-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Wei Xu <weixugc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Miaohe Lin
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33ee4f1858 |
memory tier: remove unneeded !IS_ENABLED(CONFIG_MIGRATION) check
establish_demotion_targets() is defined while CONFIG_MIGRATION is enabled. There's no need to check it again. Link: https://lkml.kernel.org/r/20230610034114.981861-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Miaohe Lin
|
e6c715abb4 |
memory tier: remove unneeded disable_all_demotion_targets() when !CONFIG_MIGRATION
There's no caller of disable_all_demotion_targets() when CONFIG_MIGRATION is disabled. Remove it. Link: https://lkml.kernel.org/r/20230606120724.208552-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Tong Tiangen
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93419139fa |
memory tier: release the new_memtier in find_create_memory_tier()
In find_create_memory_tier(), if failed to register device, then we should
release new_memtier from the tier list and put device instead of memtier.
Link: https://lkml.kernel.org/r/20230129040651.1329208-1-tongtiangen@huawei.com
Fixes:
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Miaoqian Lin
|
4a625ceee8 |
mm/demotion: fix NULL vs IS_ERR checking in memory_tier_init
alloc_memory_type() returns error pointers on error instead of NULL. Use
IS_ERR() to check the return value to fix this.
Link: https://lkml.kernel.org/r/20221110030751.1627266-1-linmq006@gmail.com
Fixes:
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Liu Shixin
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1eeaa4fd39 |
memory: move hotplug memory notifier priority to same file for easy sorting
The priority of hotplug memory callback is defined in a different file. And there are some callers using numbers directly. Collect them together into include/linux/memory.h for easy reading. This allows us to sort their priorities more intuitively without additional comments. Link: https://lkml.kernel.org/r/20220923033347.3935160-9-liushixin2@huawei.com Signed-off-by: Liu Shixin <liushixin2@huawei.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Hildenbrand <david@redhat.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Waiman Long <longman@redhat.com> Cc: zefan li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Huang Ying
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27d676a1c2 |
memory tier, sysfs: rename attribute "nodes" to "nodelist"
In sysfs, we use attribute name "cpumap" or "cpus" for cpu mask and
"cpulist" or "cpus_list" for cpu list. For example, in my system,
$ cat /sys/devices/system/node/node0/cpumap
f,ffffffff
$ cat /sys/devices/system/cpu/cpu2/topology/core_cpus
0,00100004
$ cat cat /sys/devices/system/node/node0/cpulist
0-35
$ cat /sys/devices/system/cpu/cpu2/topology/core_cpus_list
2,20
It looks reasonable to use "nodemap" for node mask and "nodelist" for
node list. So, rename the attribute to follow the naming convention.
Link: https://lkml.kernel.org/r/20221020015122.290097-1-ying.huang@intel.com
Fixes:
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Aneesh Kumar K.V
|
9832fb8783 |
mm/demotion: expose memory tier details via sysfs
Add /sys/devices/virtual/memory_tiering/ where all memory tier related details can be found. All allocated memory tiers will be listed there as /sys/devices/virtual/memory_tiering/memory_tierN/ The nodes which are part of a specific memory tier can be listed via /sys/devices/virtual/memory_tiering/memory_tierN/nodes A directory hierarchy looks like :/sys/devices/virtual/memory_tiering$ tree memory_tier4/ memory_tier4/ ├── nodes ├── subsystem -> ../../../../bus/memory_tiering └── uevent :/sys/devices/virtual/memory_tiering$ cat memory_tier4/nodes 0,2 [aneesh.kumar@linux.ibm.com: drop toptier_nodes from sysfs] Link: https://lkml.kernel.org/r/20220922102201.62168-1-aneesh.kumar@linux.ibm.com Link: https://lkml.kernel.org/r/20220830081736.119281-1-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Bharata B Rao <bharata@amd.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Hesham Almatary <hesham.almatary@huawei.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Jagdish Gediya <jvgediya.oss@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Wei Xu <weixugc@google.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Aneesh Kumar K.V
|
467b171af8 |
mm/demotion: update node_is_toptier to work with memory tiers
With memory tier support we can have memory only NUMA nodes in the top tier from which we want to avoid promotion tracking NUMA faults. Update node_is_toptier to work with memory tiers. All NUMA nodes are by default top tier nodes. With lower(slower) memory tiers added we consider all memory tiers above a memory tier having CPU NUMA nodes as a top memory tier [sj@kernel.org: include missed header file, memory-tiers.h] Link: https://lkml.kernel.org/r/20220820190720.248704-1-sj@kernel.org [akpm@linux-foundation.org: mm/memory.c needs linux/memory-tiers.h] [aneesh.kumar@linux.ibm.com: make toptier_distance inclusive upper bound of toptiers] Link: https://lkml.kernel.org/r/20220830081457.118960-1-aneesh.kumar@linux.ibm.com Link: https://lkml.kernel.org/r/20220818131042.113280-10-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: Wei Xu <weixugc@google.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Bharata B Rao <bharata@amd.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Hesham Almatary <hesham.almatary@huawei.com> Cc: Jagdish Gediya <jvgediya.oss@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Yang Shi <shy828301@gmail.com> Cc: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Jagdish Gediya
|
3200802728 |
mm/demotion: demote pages according to allocation fallback order
Currently, a higher tier node can only be demoted to selected nodes on the next lower tier as defined by the demotion path. This strict demotion order does not work in all use cases (e.g. some use cases may want to allow cross-socket demotion to another node in the same demotion tier as a fallback when the preferred demotion node is out of space). This demotion order is also inconsistent with the page allocation fallback order when all the nodes in a higher tier are out of space: The page allocation can fall back to any node from any lower tier, whereas the demotion order doesn't allow that currently. This patch adds support to get all the allowed demotion targets for a memory tier. demote_page_list() function is now modified to utilize this allowed node mask as the fallback allocation mask. Link: https://lkml.kernel.org/r/20220818131042.113280-9-aneesh.kumar@linux.ibm.com Signed-off-by: Jagdish Gediya <jvgediya.oss@gmail.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: Wei Xu <weixugc@google.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Bharata B Rao <bharata@amd.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Hesham Almatary <hesham.almatary@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Yang Shi <shy828301@gmail.com> Cc: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Aneesh Kumar K.V
|
b26ac6f3ba |
mm/demotion: drop memtier from memtype
Now that we track node-specific memtier in pg_data_t, we can drop memtier from memtype. Link: https://lkml.kernel.org/r/20220818131042.113280-8-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: Wei Xu <weixugc@google.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Bharata B Rao <bharata@amd.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Hesham Almatary <hesham.almatary@huawei.com> Cc: Jagdish Gediya <jvgediya.oss@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Yang Shi <shy828301@gmail.com> Cc: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Aneesh Kumar K.V
|
7766cf7a7e |
mm/demotion: add pg_data_t member to track node memory tier details
Also update different helpes to use NODE_DATA()->memtier. Since node specific memtier can change based on the reassignment of NUMA node to a different memory tiers, accessing NODE_DATA()->memtier needs to happen under an rcu read lock or memory_tier_lock. Link: https://lkml.kernel.org/r/20220818131042.113280-7-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: Wei Xu <weixugc@google.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Bharata B Rao <bharata@amd.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Hesham Almatary <hesham.almatary@huawei.com> Cc: Jagdish Gediya <jvgediya.oss@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Yang Shi <shy828301@gmail.com> Cc: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Aneesh Kumar K.V
|
6c542ab757 |
mm/demotion: build demotion targets based on explicit memory tiers
This patch switch the demotion target building logic to use memory tiers instead of NUMA distance. All N_MEMORY NUMA nodes will be placed in the default memory tier and additional memory tiers will be added by drivers like dax kmem. This patch builds the demotion target for a NUMA node by looking at all memory tiers below the tier to which the NUMA node belongs. The closest node in the immediately following memory tier is used as a demotion target. Since we are now only building demotion target for N_MEMORY NUMA nodes the CPU hotplug calls are removed in this patch. Link: https://lkml.kernel.org/r/20220818131042.113280-6-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: Wei Xu <weixugc@google.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Bharata B Rao <bharata@amd.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Hesham Almatary <hesham.almatary@huawei.com> Cc: Jagdish Gediya <jvgediya.oss@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Yang Shi <shy828301@gmail.com> Cc: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Aneesh Kumar K.V
|
7b88bda376 |
mm/demotion/dax/kmem: set node's abstract distance to MEMTIER_DEFAULT_DAX_ADISTANCE
By default, all nodes are assigned to the default memory tier which is the memory tier designated for nodes with DRAM Set dax kmem device node's tier to slower memory tier by assigning abstract distance to MEMTIER_DEFAULT_DAX_ADISTANCE. Low-level drivers like papr_scm or ACPI NFIT can initialize memory device type to a more accurate value based on device tree details or HMAT. If the kernel doesn't find the memory type initialized, a default slower memory type is assigned by the kmem driver. [aneesh.kumar@linux.ibm.com: assign correct memory type for multiple dax devices with the same node affinity] Link: https://lkml.kernel.org/r/20220826100224.542312-1-aneesh.kumar@linux.ibm.com Link: https://lkml.kernel.org/r/20220818131042.113280-5-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: Wei Xu <weixugc@google.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Bharata B Rao <bharata@amd.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Hesham Almatary <hesham.almatary@huawei.com> Cc: Jagdish Gediya <jvgediya.oss@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Yang Shi <shy828301@gmail.com> Cc: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Aneesh Kumar K.V
|
c6123a19c9 |
mm/demotion: add hotplug callbacks to handle new numa node onlined
If the new NUMA node onlined doesn't have a abstract distance assigned, the kernel adds the NUMA node to default memory tier. [aneesh.kumar@linux.ibm.com: fix kernel error with memory hotplug] Link: https://lkml.kernel.org/r/20220825092019.379069-1-aneesh.kumar@linux.ibm.com Link: https://lkml.kernel.org/r/20220818131042.113280-4-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: Wei Xu <weixugc@google.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Bharata B Rao <bharata@amd.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Hesham Almatary <hesham.almatary@huawei.com> Cc: Jagdish Gediya <jvgediya.oss@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Yang Shi <shy828301@gmail.com> Cc: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Aneesh Kumar K.V
|
9195244022 |
mm/demotion: move memory demotion related code
This moves memory demotion related code to mm/memory-tiers.c. No functional change in this patch. Link: https://lkml.kernel.org/r/20220818131042.113280-3-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: Wei Xu <weixugc@google.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Bharata B Rao <bharata@amd.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Hesham Almatary <hesham.almatary@huawei.com> Cc: Jagdish Gediya <jvgediya.oss@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Yang Shi <shy828301@gmail.com> Cc: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Aneesh Kumar K.V
|
992bf77591 |
mm/demotion: add support for explicit memory tiers
Patch series "mm/demotion: Memory tiers and demotion", v15. The current kernel has the basic memory tiering support: Inactive pages on a higher tier NUMA node can be migrated (demoted) to a lower tier NUMA node to make room for new allocations on the higher tier NUMA node. Frequently accessed pages on a lower tier NUMA node can be migrated (promoted) to a higher tier NUMA node to improve the performance. In the current kernel, memory tiers are defined implicitly via a demotion path relationship between NUMA nodes, which is created during the kernel initialization and updated when a NUMA node is hot-added or hot-removed. The current implementation puts all nodes with CPU into the highest tier, and builds the tier hierarchy tier-by-tier by establishing the per-node demotion targets based on the distances between nodes. This current memory tier kernel implementation needs to be improved for several important use cases: * The current tier initialization code always initializes each memory-only NUMA node into a lower tier. But a memory-only NUMA node may have a high performance memory device (e.g. a DRAM-backed memory-only node on a virtual machine) and that should be put into a higher tier. * The current tier hierarchy always puts CPU nodes into the top tier. But on a system with HBM (e.g. GPU memory) devices, these memory-only HBM NUMA nodes should be in the top tier, and DRAM nodes with CPUs are better to be placed into the next lower tier. * Also because the current tier hierarchy always puts CPU nodes into the top tier, when a CPU is hot-added (or hot-removed) and triggers a memory node from CPU-less into a CPU node (or vice versa), the memory tier hierarchy gets changed, even though no memory node is added or removed. This can make the tier hierarchy unstable and make it difficult to support tier-based memory accounting. * A higher tier node can only be demoted to nodes with shortest distance on the next lower tier as defined by the demotion path, not any other node from any lower tier. This strict, demotion order does not work in all use cases (e.g. some use cases may want to allow cross-socket demotion to another node in the same demotion tier as a fallback when the preferred demotion node is out of space), and has resulted in the feature request for an interface to override the system-wide, per-node demotion order from the userspace. This demotion order is also inconsistent with the page allocation fallback order when all the nodes in a higher tier are out of space: The page allocation can fall back to any node from any lower tier, whereas the demotion order doesn't allow that. This patch series make the creation of memory tiers explicit under the control of device driver. Memory Tier Initialization ========================== Linux kernel presents memory devices as NUMA nodes and each memory device is of a specific type. The memory type of a device is represented by its abstract distance. A memory tier corresponds to a range of abstract distance. This allows for classifying memory devices with a specific performance range into a memory tier. By default, all memory nodes are assigned to the default tier with abstract distance 512. A device driver can move its memory nodes from the default tier. For example, PMEM can move its memory nodes below the default tier, whereas GPU can move its memory nodes above the default tier. The kernel initialization code makes the decision on which exact tier a memory node should be assigned to based on the requests from the device drivers as well as the memory device hardware information provided by the firmware. Hot-adding/removing CPUs doesn't affect memory tier hierarchy. This patch (of 10): In the current kernel, memory tiers are defined implicitly via a demotion path relationship between NUMA nodes, which is created during the kernel initialization and updated when a NUMA node is hot-added or hot-removed. The current implementation puts all nodes with CPU into the highest tier, and builds the tier hierarchy by establishing the per-node demotion targets based on the distances between nodes. This current memory tier kernel implementation needs to be improved for several important use cases, The current tier initialization code always initializes each memory-only NUMA node into a lower tier. But a memory-only NUMA node may have a high performance memory device (e.g. a DRAM-backed memory-only node on a virtual machine) that should be put into a higher tier. The current tier hierarchy always puts CPU nodes into the top tier. But on a system with HBM or GPU devices, the memory-only NUMA nodes mapping these devices should be in the top tier, and DRAM nodes with CPUs are better to be placed into the next lower tier. With current kernel higher tier node can only be demoted to nodes with shortest distance on the next lower tier as defined by the demotion path, not any other node from any lower tier. This strict, demotion order does not work in all use cases (e.g. some use cases may want to allow cross-socket demotion to another node in the same demotion tier as a fallback when the preferred demotion node is out of space), This demotion order is also inconsistent with the page allocation fallback order when all the nodes in a higher tier are out of space: The page allocation can fall back to any node from any lower tier, whereas the demotion order doesn't allow that. This patch series address the above by defining memory tiers explicitly. Linux kernel presents memory devices as NUMA nodes and each memory device is of a specific type. The memory type of a device is represented by its abstract distance. A memory tier corresponds to a range of abstract distance. This allows for classifying memory devices with a specific performance range into a memory tier. This patch configures the range/chunk size to be 128. The default DRAM abstract distance is 512. We can have 4 memory tiers below the default DRAM with abstract distance range 0 - 127, 127 - 255, 256- 383, 384 - 511. Faster memory devices can be placed in these faster(higher) memory tiers. Slower memory devices like persistent memory will have abstract distance higher than the default DRAM level. [akpm@linux-foundation.org: fix comment, per Aneesh] Link: https://lkml.kernel.org/r/20220818131042.113280-1-aneesh.kumar@linux.ibm.com Link: https://lkml.kernel.org/r/20220818131042.113280-2-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: Wei Xu <weixugc@google.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Bharata B Rao <bharata@amd.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Hesham Almatary <hesham.almatary@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Jagdish Gediya <jvgediya.oss@gmail.com> Cc: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |