- May 05, 2024
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Sidhartha Kumar authored
dissolve_free_huge_pages() only uses folios internally, rename it to dissolve_free_hugetlb_folios() and change the comments which reference it. [akpm@linux-foundation.org: remove unneeded `extern'] Link: https://lkml.kernel.org/r/20240412182139.120871-2-sidhartha.kumar@oracle.com Signed-off-by:
Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by:
Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by:
Miaohe Lin <linmiaohe@huawei.com> Cc: Jane Chu <jane.chu@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org>
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- Apr 25, 2024
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Baolin Wang authored
Patch series "make the hugetlb migration strategy consistent", v2. As discussed in previous thread [1], there is an inconsistency when handling hugetlb migration. When handling the migration of freed hugetlb, it prevents fallback to other NUMA nodes in alloc_and_dissolve_hugetlb_folio(). However, when dealing with in-use hugetlb, it allows fallback to other NUMA nodes in alloc_hugetlb_folio_nodemask(), which can break the per-node hugetlb pool and might result in unexpected failures when node bound workloads doesn't get what is asssumed available. This patchset tries to make the hugetlb migration strategy more clear and consistent. Please find details in each patch. [1] https://lore.kernel.org/all/6f26ce22d2fcd523418a085f2c588fe0776d46e7.1706794035.git.baolin.wang@linux.alibaba.com/ This patch (of 2): To support different hugetlb allocation strategies during hugetlb migration based on various migration reasons, record the migration reason in the migration_target_control structure as a preparation. Link: https://lkml.kernel.org/r/cover.1709719720.git.baolin.wang@linux.alibaba.com Link: https://lkml.kernel.org/r/7b95d4981e07211f57139fc5b1f7ce91b920cee4.1709719720.git.baolin.wang@linux.alibaba.com Signed-off-by:
Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by:
Oscar Salvador <osalvador@suse.de> Cc: David Hildenbrand <david@redhat.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Signed-off-by:
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- Feb 22, 2024
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Vishal Verma authored
In preparation for adding sysfs ABI to toggle memmap_on_memory semantics for drivers adding memory, export the mhp_supports_memmap_on_memory() helper. This allows drivers to check if memmap_on_memory support is available before trying to request it, and display an appropriate message if it isn't available. As part of this, remove the size argument to this - with recent updates to allow memmap_on_memory for larger ranges, and the internal splitting of altmaps into respective memory blocks, the size argument is meaningless. [akpm@linux-foundation.org: fix build] Link: https://lkml.kernel.org/r/20240124-vv-dax_abi-v7-4-20d16cb8d23d@intel.com Signed-off-by:
Vishal Verma <vishal.l.verma@intel.com> Acked-by:
David Hildenbrand <david@redhat.com> Suggested-by:
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- Feb 21, 2024
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Sumanth Korikkar authored
Patch series "implement "memmap on memory" feature on s390". This series provides "memmap on memory" support on s390 platform. "memmap on memory" allows struct pages array to be allocated from the hotplugged memory range instead of allocating it from main system memory. s390 currently preallocates struct pages array for all potentially possible memory, which ensures memory onlining always succeeds, but with the cost of significant memory consumption from the available system memory during boottime. In certain extreme configuration, this could lead to ipl failure. "memmap on memory" ensures struct pages array are populated from self contained hotplugged memory range instead of depleting the available system memory and this could eliminate ipl failure on s390 platform. On other platforms, system might go OOM when the physically hotplugged memory depletes the available memory before it is onlined. Hence, "memmap on memory" feature was introduced as described in commit a08a2ae3 ("mm,memory_hotplug: allocate memmap from the added memory range"). Unlike other architectures, s390 memory blocks are not physically accessible until it is online. To make it physically accessible two new memory notifiers MEM_PREPARE_ONLINE / MEM_FINISH_OFFLINE are added and this notifier lets the hypervisor inform that the memory should be made physically accessible. This allows for "memmap on memory" initialization during memory hotplug onlining phase, which is performed before calling MEM_GOING_ONLINE notifier. Patch 1 introduces MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE memory notifiers to prepare the transition of memory to and from a physically accessible state. New mhp_flag MHP_OFFLINE_INACCESSIBLE is introduced to ensure altmap cannot be written when adding memory - before it is set online. This enhancement is crucial for implementing the "memmap on memory" feature for s390 in a subsequent patch. Patches 2 allocates vmemmap pages from self-contained memory range for s390. It allocates memory map (struct pages array) from the hotplugged memory range, rather than using system memory by passing altmap to vmemmap functions. Patch 3 removes unhandled memory notifier types on s390. Patch 4 implements MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE memory notifiers on s390. MEM_PREPARE_ONLINE memory notifier makes memory block physical accessible via sclp assign command. The notifier ensures self-contained memory maps are accessible and hence enabling the "memmap on memory" on s390. MEM_FINISH_OFFLINE memory notifier shifts the memory block to an inaccessible state via sclp unassign command. Patch 5 finally enables MHP_MEMMAP_ON_MEMORY on s390. This patch (of 5): Introduce MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE memory notifiers to prepare the transition of memory to and from a physically accessible state. This enhancement is crucial for implementing the "memmap on memory" feature for s390 in a subsequent patch. Platforms such as x86 can support physical memory hotplug via ACPI. When there is physical memory hotplug, ACPI event leads to the memory addition with the following callchain: acpi_memory_device_add() -> acpi_memory_enable_device() -> __add_memory() After this, the hotplugged memory is physically accessible, and altmap support prepared, before the "memmap on memory" initialization in memory_block_online() is called. On s390, memory hotplug works in a different way. The available hotplug memory has to be defined upfront in the hypervisor, but it is made physically accessible only when the user sets it online via sysfs, currently in the MEM_GOING_ONLINE notifier. This is too late and "memmap on memory" initialization is performed before calling MEM_GOING_ONLINE notifier. During the memory hotplug addition phase, altmap support is prepared and during the memory onlining phase s390 requires memory to be physically accessible and then subsequently initiate the "memmap on memory" initialization process. The memory provider will handle new MEM_PREPARE_ONLINE / MEM_FINISH_OFFLINE notifications and make the memory accessible. The mhp_flag MHP_OFFLINE_INACCESSIBLE is introduced and is relevant when used along with MHP_MEMMAP_ON_MEMORY, because the altmap cannot be written (e.g., poisoned) when adding memory -- before it is set online. This allows for adding memory with an altmap that is not currently made available by a hypervisor. When onlining that memory, the hypervisor can be instructed to make that memory accessible via the new notifiers and the onlining phase will not require any memory allocations, which is helpful in low-memory situations. All architectures ignore unknown memory notifiers. Therefore, the introduction of these new notifiers does not result in any functional modifications across architectures. Link: https://lkml.kernel.org/r/20240108132747.3238763-1-sumanthk@linux.ibm.com Link: https://lkml.kernel.org/r/20240108132747.3238763-2-sumanthk@linux.ibm.com Signed-off-by:
Sumanth Korikkar <sumanthk@linux.ibm.com> Suggested-by:
Gerald Schaefer <gerald.schaefer@linux.ibm.com> Suggested-by:
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- Jan 12, 2024
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Sumanth Korikkar authored
set_memmap_mode() stores the kernel parameter memmap mode as an integer. However, the get_memmap_mode() function utilizes param_get_bool() to fetch the value as a boolean, leading to potential endianness issue. On Big-endian architectures, the memmap_on_memory is consistently displayed as 'N' regardless of its actual status. To address this endianness problem, the solution involves obtaining the mode as an integer. This adjustment ensures the proper display of the memmap_on_memory parameter, presenting it as one of the following options: Force, Y, or N. Link: https://lkml.kernel.org/r/20240110140127.241451-1-sumanthk@linux.ibm.com Fixes: 2d1f649c ("mm/memory_hotplug: support memmap_on_memory when memmap is not aligned to pageblocks") Signed-off-by:
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- Jan 08, 2024
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Kirill A. Shutemov authored
commit 23baf831 ("mm, treewide: redefine MAX_ORDER sanely") has changed the definition of MAX_ORDER to be inclusive. This has caused issues with code that was not yet upstream and depended on the previous definition. To draw attention to the altered meaning of the define, rename MAX_ORDER to MAX_PAGE_ORDER. Link: https://lkml.kernel.org/r/20231228144704.14033-2-kirill.shutemov@linux.intel.com Signed-off-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
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- Dec 10, 2023
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Vishal Verma authored
The MHP_MEMMAP_ON_MEMORY flag for hotplugged memory is restricted to 'memblock_size' chunks of memory being added. Adding a larger span of memory precludes memmap_on_memory semantics. For users of hotplug such as kmem, large amounts of memory might get added from the CXL subsystem. In some cases, this amount may exceed the available 'main memory' to store the memmap for the memory being added. In this case, it is useful to have a way to place the memmap on the memory being added, even if it means splitting the addition into memblock-sized chunks. Change add_memory_resource() to loop over memblock-sized chunks of memory if caller requested memmap_on_memory, and if other conditions for it are met. Teach try_remove_memory() to also expect that a memory range being removed might have been split up into memblock sized chunks, and to loop through those as needed. This does preclude being able to use PUD mappings in the direct map; a proposal to how this could be optimized in the future is laid out here[1]. [1]: https://lore.kernel.org/linux-mm/b6753402-2de9-25b2-36e9-eacd49752b19@redhat.com/ Link: https://lkml.kernel.org/r/20231107-vv-kmem_memmap-v10-2-1253ec050ed0@intel.com Signed-off-by:
Dan Williams <dan.j.williams@intel.com> Reviewed-by:
"Huang, Ying" <ying.huang@intel.com> Acked-by:
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Vishal Verma authored
Patch series "mm: use memmap_on_memory semantics for dax/kmem", v10. The dax/kmem driver can potentially hot-add large amounts of memory originating from CXL memory expanders, or NVDIMMs, or other 'device memories'. There is a chance there isn't enough regular system memory available to fit the memmap for this new memory. It's therefore desirable, if all other conditions are met, for the kmem managed memory to place its memmap on the newly added memory itself. The main hurdle for accomplishing this for kmem is that memmap_on_memory can only be done if the memory being added is equal to the size of one memblock. To overcome this, allow the hotplug code to split an add_memory() request into memblock-sized chunks, and try_remove_memory() to also expect and handle such a scenario. Patch 1 replaces an open-coded kmemdup() Patch 2 teaches the memory_hotplug code to allow for splitting add_memory() and remove_memory() requests over memblock sized chunks. Patch 3 allows the dax region drivers to request memmap_on_memory semantics. CXL dax regions default this to 'on', all others default to off to keep existing behavior unchanged. This patch (of 3): A review of the memmap_on_memory modifications to add_memory_resource() revealed an instance of an open-coded kmemdup(). Replace it with kmemdup(). Link: https://lkml.kernel.org/r/20231107-vv-kmem_memmap-v10-0-1253ec050ed0@intel.com Link: https://lkml.kernel.org/r/20231107-vv-kmem_memmap-v10-1-1253ec050ed0@intel.com Signed-off-by:
Fan Ni <fan.ni@samsung.com> Reported-by:
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- Dec 06, 2023
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Sumanth Korikkar authored
In add_memory_resource(), creation of memory block devices occurs after successful call to arch_add_memory(). However, creation of memory block devices could fail. In that case, arch_remove_memory() is called to perform necessary cleanup. Currently with or without altmap support, arch_remove_memory() is always passed with altmap set to NULL during error handling. This leads to freeing of struct pages using free_pages(), eventhough the allocation might have been performed with altmap support via altmap_alloc_block_buf(). Fix the error handling by passing altmap in arch_remove_memory(). This ensures the following: * When altmap is disabled, deallocation of the struct pages array occurs via free_pages(). * When altmap is enabled, deallocation occurs via vmem_altmap_free(). Link: https://lkml.kernel.org/r/20231120145354.308999-3-sumanthk@linux.ibm.com Fixes: a08a2ae3 ("mm,memory_hotplug: allocate memmap from the added memory range") Signed-off-by:
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Sumanth Korikkar authored
From Documentation/core-api/memory-hotplug.rst: When adding/removing/onlining/offlining memory or adding/removing heterogeneous/device memory, we should always hold the mem_hotplug_lock in write mode to serialise memory hotplug (e.g. access to global/zone variables). mhp_(de)init_memmap_on_memory() functions can change zone stats and struct page content, but they are currently called w/o the mem_hotplug_lock. When memory block is being offlined and when kmemleak goes through each populated zone, the following theoretical race conditions could occur: CPU 0: | CPU 1: memory_offline() | -> offline_pages() | -> mem_hotplug_begin() | ... | -> mem_hotplug_done() | | kmemleak_scan() | -> get_online_mems() | ... -> mhp_deinit_memmap_on_memory() | [not protected by mem_hotplug_begin/done()]| Marks memory section as offline, | Retrieves zone_start_pfn poisons vmemmap struct pages and updates | and struct page members. the zone related data | | ... | -> put_online_mems() Fix this by ensuring mem_hotplug_lock is taken before performing mhp_init_memmap_on_memory(). Also ensure that mhp_deinit_memmap_on_memory() holds the lock. online/offline_pages() are currently only called from memory_block_online/offline(), so it is safe to move the locking there. Link: https://lkml.kernel.org/r/20231120145354.308999-2-sumanthk@linux.ibm.com Fixes: a08a2ae3 ("mm,memory_hotplug: allocate memmap from the added memory range") Signed-off-by:
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- Oct 25, 2023
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Qi Zheng authored
In offline_pages(), if a node becomes memoryless, we will clear its N_MEMORY state by calling node_states_clear_node(). But we do this after rebuilding the zonelists by calling build_all_zonelists(), which will cause this memoryless node to still be in the fallback nodes (node_order[]) of other nodes. To drop memoryless nodes from fallback nodes in this case, just call node_states_clear_node() before calling build_all_zonelists(). In this way, we will not try to allocate pages from memoryless node0, then the panic mentioned in [1] will also be fixed. Even though this problem has been solved by dropping the NODE_MIN_SIZE constrain in x86 [2], it would be better to fix it in the core MM as well. https://lore.kernel.org/all/20230212110305.93670-1-zhengqi.arch@bytedance.com/ [1] https://lore.kernel.org/all/20231017062215.171670-1-rppt@kernel.org/ [2] Link: https://lkml.kernel.org/r/9f1dbe7ee1301c7163b2770e32954ff5e3ecf2c4.1697711415.git.zhengqi.arch@bytedance.com Signed-off-by:
Qi Zheng <zhengqi.arch@bytedance.com> Acked-by:
Ingo Molnar <mingo@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
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- Oct 04, 2023
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Zi Yan authored
When dealing with hugetlb pages, manipulating struct page pointers directly can get to wrong struct page, since struct page is not guaranteed to be contiguous on SPARSEMEM without VMEMMAP. Use pfn calculation to handle it properly. Without the fix, a wrong number of page might be skipped. Since skip cannot be negative, scan_movable_page() will end early and might miss a movable page with -ENOENT. This might fail offline_pages(). No bug is reported. The fix comes from code inspection. Link: https://lkml.kernel.org/r/20230913201248.452081-4-zi.yan@sent.com Fixes: eeb0efd0 ("mm,memory_hotplug: fix scan_movable_pages() for gigantic hugepages") Signed-off-by:
Zi Yan <ziy@nvidia.com> Reviewed-by:
Muchun Song <songmuchun@bytedance.com> Acked-by:
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- Aug 21, 2023
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Aneesh Kumar K.V authored
With memmap on memory, some architecture needs more details w.r.t altmap such as base_pfn, end_pfn, etc to unmap vmemmap memory. Instead of computing them again when we remove a memory block, embed vmem_altmap details in struct memory_block if we are using memmap on memory block feature. [yangyingliang@huawei.com: fix error return code in add_memory_resource()] Link: https://lkml.kernel.org/r/20230809081552.1351184-1-yangyingliang@huawei.com Link: https://lkml.kernel.org/r/20230808091501.287660-7-aneesh.kumar@linux.ibm.com Signed-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by:
Yang Yingliang <yangyingliang@huawei.com> Acked-by:
Michal Hocko <mhocko@suse.com> Acked-by:
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Aneesh Kumar K.V authored
Currently, memmap_on_memory feature is only supported with memory block sizes that result in vmemmap pages covering full page blocks. This is because memory onlining/offlining code requires applicable ranges to be pageblock-aligned, for example, to set the migratetypes properly. This patch helps to lift that restriction by reserving more pages than required for vmemmap space. This helps the start address to be page block aligned with different memory block sizes. Using this facility implies the kernel will be reserving some pages for every memoryblock. This allows the memmap on memory feature to be widely useful with different memory block size values. For ex: with 64K page size and 256MiB memory block size, we require 4 pages to map vmemmap pages, To align things correctly we end up adding a reserve of 28 pages. ie, for every 4096 pages 28 pages get reserved. Link: https://lkml.kernel.org/r/20230808091501.287660-5-aneesh.kumar@linux.ibm.com Signed-off-by:
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Aneesh Kumar K.V authored
Some architectures would want different restrictions. Hence add an architecture-specific override. The PMD_SIZE check is moved there. Link: https://lkml.kernel.org/r/20230808091501.287660-4-aneesh.kumar@linux.ibm.com Signed-off-by:
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Aneesh Kumar K.V authored
If not supported, fallback to not using memap on memmory. This avoids the need for callers to do the fallback. Link: https://lkml.kernel.org/r/20230808091501.287660-3-aneesh.kumar@linux.ibm.com Signed-off-by:
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- Aug 18, 2023
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David Hildenbrand authored
Let's update the documentation that any signal is sufficient, and add a comment that not only checking for fatal signals is historical baggage: changing it now could break existing user space. although unlikely. For example, when an app provides a custom SIGALRM handler and triggers memory offlining, the timeout cmd would no longer stop memory offlining, because SIGALRM would no longer be considered a fatal signal. Note that using signal_pending() instead of fatal_signal_pending() is an anti-pattern, but slowly deprecating that behavior to eventually change it in the far future is probably not worth the effort. If this ever becomes relevant for user-space, we might want to rethink. Link: https://lkml.kernel.org/r/20230711174050.603820-1-david@redhat.com Signed-off-by:
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- Jun 23, 2023
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Matthew Wilcox (Oracle) authored
These files no longer need pagevec.h, mostly due to function declarations being moved out of it. Link: https://lkml.kernel.org/r/20230621164557.3510324-14-willy@infradead.org Signed-off-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by:
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- Jun 19, 2023
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Haifeng Xu authored
reset_node_present_pages() only get called in hotadd_init_pgdat(), move the action that clear present pages to free_area_init_core_hotplug(), so the helper can be removed. Link: https://lkml.kernel.org/r/20230607025056.1348-1-haifeng.xu@shopee.com Signed-off-by:
Haifeng Xu <haifeng.xu@shopee.com> Suggested-by:
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Haifeng Xu authored
managed pages has already been set to 0 in free_area_init_core_hotplug(), via zone_init_internals() on each zone. It's pointless to reset again. Furthermore, reset_node_managed_pages() no longer needs to be exposed outside of mm/memblock.c. Remove declaration in include/linux/memblock.h and define it as static. In addtion to this, the only caller of reset_node_managed_pages() is reset_all_zones_managed_pages(), which is annotated with __init, so it should be safe to also mark reset_node_managed_pages() as __init. Link: https://lkml.kernel.org/r/20230607024548.1240-1-haifeng.xu@shopee.com Signed-off-by:
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Yajun Deng authored
These parameters ms and map_offset are not used in sparse_remove_section(), so remove them. The __remove_section() is only called by __remove_pages(), remove it. And put the WARN_ON_ONCE() in sparse_remove_section(). Link: https://lkml.kernel.org/r/20230607023952.2247489-1-yajun.deng@linux.dev Signed-off-by:
Yajun Deng <yajun.deng@linux.dev> Reviewed-by:
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- Jun 09, 2023
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Rick Wertenbroek authored
The format string in __add_pages and __remove_pages has a typo and prints e.g., "Misaligned __add_pages start: 0xfc605 end: #fc609" instead of "Misaligned __add_pages start: 0xfc605 end: 0xfc609" Fix "#%lx" => "%#lx" Link: https://lkml.kernel.org/r/20230510090758.3537242-1-rick.wertenbroek@gmail.com Signed-off-by:
Rick Wertenbroek <rick.wertenbroek@gmail.com> Reviewed-by:
Mike Rapoport (IBM) <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by:
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- Apr 18, 2023
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Kirill A. Shutemov authored
23baf831 ("mm, treewide: redefine MAX_ORDER sanely") results in various boot failures (hang) on arm targets Debug messages reveal the reason. ########### MAX_ORDER=10 start=0 __ffs(start)=-1 min()=10 min_t=-1 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ If start==0, __ffs(start) returns 0xfffffff or (as int) -1, which min_t() interprets as such, while min() apparently uses the returned unsigned long value. Obviously a negative order isn't received well by the rest of the code. [akpm@linux-foundation.org: fix comment, per Mike] Link: https://lkml.kernel.org/r/ZDBa7HWZK69dKKzH@kernel.org Link: https://lkml.kernel.org/r/20230406072529.vupqyrzqnhyozeyh@box.shutemov.name Fixes: 23baf831 ("mm, treewide: redefine MAX_ORDER sanely") Signed-off-by:
"Kirill A. Shutemov" <kirill@shutemov.name> Reported-by:
Guenter Roeck <linux@roeck-us.net> Link: https://lkml.kernel.org/r/9460377a-38aa-4f39-ad57-fb73725f92db@roeck-us.net Reviewed-by:
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- Apr 05, 2023
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Kirill A. Shutemov authored
MAX_ORDER currently defined as number of orders page allocator supports: user can ask buddy allocator for page order between 0 and MAX_ORDER-1. This definition is counter-intuitive and lead to number of bugs all over the kernel. Change the definition of MAX_ORDER to be inclusive: the range of orders user can ask from buddy allocator is 0..MAX_ORDER now. [kirill@shutemov.name: fix min() warning] Link: https://lkml.kernel.org/r/20230315153800.32wib3n5rickolvh@box [akpm@linux-foundation.org: fix another min_t warning] [kirill@shutemov.name: fixups per Zi Yan] Link: https://lkml.kernel.org/r/20230316232144.b7ic4cif4kjiabws@box.shutemov.name [akpm@linux-foundation.org: fix underlining in docs] Link: https://lore.kernel.org/oe-kbuild-all/202303191025.VRCTk6mP-lkp@intel.com/ Link: https://lkml.kernel.org/r/20230315113133.11326-11-kirill.shutemov@linux.intel.com Signed-off-by:
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- Feb 20, 2023
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SeongJae Park authored
Return value mechanism of do_migrate_range() is not very simple, while no caller of the function checks the return value. Make the function return nothing to be more simple, and cleanup related unnecessary code. Link: https://lkml.kernel.org/r/20230216170703.64574-1-sj@kernel.org Suggested-by:
SeongJae Park <sj@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by:
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Baolin Wang authored
Now the isolate_movable_page() can only return 0 or -EBUSY, and no users will care about the negative return value, thus we can convert the isolate_movable_page() to return a boolean value to make the code more clear when checking the movable page isolation state. No functional changes intended. [akpm@linux-foundation.org: remove unneeded comment, per Matthew] Link: https://lkml.kernel.org/r/cb877f73f4fff8d309611082ec740a7065b1ade0.1676424378.git.baolin.wang@linux.alibaba.com Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by:
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Baolin Wang authored
The isolate_lru_page() can only return 0 or -EBUSY, and most users did not care about the negative error of isolate_lru_page(), except one user in add_page_for_migration(). So we can convert the isolate_lru_page() to return a boolean value, which can help to make the code more clear when checking the return value of isolate_lru_page(). Also convert all users' logic of checking the isolation state. No functional changes intended. Link: https://lkml.kernel.org/r/3074c1ab628d9dbf139b33f248a8bc253a3f95f0.1676424378.git.baolin.wang@linux.alibaba.com Signed-off-by:
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- Feb 13, 2023
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Sidhartha Kumar authored
Patch series "continue hugetlb folio conversion", v3. This series continues the conversion of core hugetlb functions to use folios. This series converts many helper funtions in the hugetlb fault path. This is in preparation for another series to convert the hugetlb fault code paths to operate on folios. This patch (of 8): Convert isolate_hugetlb() to take in a folio and convert its callers to pass a folio. Use page_folio() to convert the callers to use a folio is safe as isolate_hugetlb() operates on a head page. Link: https://lkml.kernel.org/r/20230113223057.173292-1-sidhartha.kumar@oracle.com Link: https://lkml.kernel.org/r/20230113223057.173292-2-sidhartha.kumar@oracle.com Signed-off-by:
Mike Kravetz <mike.kravetz@oracle.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by:
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- Oct 03, 2022
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Kefeng Wang authored
Add pageblock_aligned() and use it to simplify code. Link: https://lkml.kernel.org/r/20220907060844.126891-3-wangkefeng.wang@huawei.com Signed-off-by:
Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by:
Mike Rapoport <rppt@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
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- Sep 11, 2022
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Kefeng Wang authored
kswapd_run/stop() will set pgdat->kswapd to NULL, which could race with kswapd_is_running() in kcompactd(), kswapd_run/stop() kcompactd() kswapd_is_running() pgdat->kswapd // error or nomal ptr verify pgdat->kswapd // load non-NULL pgdat->kswapd pgdat->kswapd = NULL task_is_running(pgdat->kswapd) // Null pointer derefence KASAN reports the null-ptr-deref shown below, vmscan: Failed to start kswapd on node 0 ... BUG: KASAN: null-ptr-deref in kcompactd+0x440/0x504 Read of size 8 at addr 0000000000000024 by task kcompactd0/37 CPU: 0 PID: 37 Comm: kcompactd0 Kdump: loaded Tainted: G OE 5.10.60 #1 Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015 Call trace: dump_backtrace+0x0/0x394 show_stack+0x34/0x4c dump_stack+0x158/0x1e4 __kasan_report+0x138/0x140 kasan_report+0x44/0xdc __asan_load8+0x94/0xd0 kcompactd+0x440/0x504 kthread+0x1a4/0x1f0 ret_from_fork+0x10/0x18 At present kswapd/kcompactd_run() and kswapd/kcompactd_stop() are protected by mem_hotplug_begin/done(), but without kcompactd(). There is no need to involve memory hotplug lock in kcompactd(), so let's add a new mutex to protect pgdat->kswapd accesses. Also, because the kcompactd task will check the state of kswapd task, it's better to call kcompactd_stop() before kswapd_stop() to reduce lock conflicts. [akpm@linux-foundation.org: add comments] Link: https://lkml.kernel.org/r/20220827111959.186838-1-wangkefeng.wang@huawei.com Signed-off-by: -
Kefeng Wang authored
Directly check state of struct memory_block, no need a single function. Link: https://lkml.kernel.org/r/20220827112043.187028-1-wangkefeng.wang@huawei.com Signed-off-by:
Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by:
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- Jul 29, 2022
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Kefeng Wang authored
Use is_zone_movable_page() helper to simplify code. Link: https://lkml.kernel.org/r/20220726131135.146912-1-wangkefeng.wang@huawei.com Signed-off-by:
Pankaj Gupta <pankaj.gupta@amd.com> Acked-by:
Jason Wang <jasowang@redhat.com> Signed-off-by:
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- Jul 03, 2022
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Muchun Song authored
For now, the feature of hugetlb_free_vmemmap is not compatible with the feature of memory_hotplug.memmap_on_memory, and hugetlb_free_vmemmap takes precedence over memory_hotplug.memmap_on_memory. However, someone wants to make memory_hotplug.memmap_on_memory takes precedence over hugetlb_free_vmemmap since memmap_on_memory makes it more likely to succeed memory hotplug in close-to-OOM situations. So the decision of making hugetlb_free_vmemmap take precedence is not wise and elegant. The proper approach is to have hugetlb_vmemmap.c do the check whether the section which the HugeTLB pages belong to can be optimized. If the section's vmemmap pages are allocated from the added memory block itself, hugetlb_free_vmemmap should refuse to optimize the vmemmap, otherwise, do the optimization. Then both kernel parameters are compatible. So this patch introduces VmemmapSelfHosted to mask any non-optimizable vmemmap pages. The hugetlb_vmemmap can use this flag to detect if a vmemmap page can be optimized. [songmuchun@bytedance.com: walk vmemmap page tables to avoid false-positive] Link: https://lkml.kernel.org/r/20220620110616.12056-3-songmuchun@bytedance.com Link: https://lkml.kernel.org/r/20220617135650.74901-3-songmuchun@bytedance.com Signed-off-by:
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Muchun Song authored
Patch series "make hugetlb_optimize_vmemmap compatible with memmap_on_memory", v3. This series makes hugetlb_optimize_vmemmap compatible with memmap_on_memory. This patch (of 2): We are almost running out of section flags, only one bit is available in the worst case (powerpc with 256k pages). However, there are still some free bits (in ->section_mem_map) on other architectures (e.g. x86_64 has 10 bits available, arm64 has 8 bits available with worst case of 64K pages). We have hard coded those numbers in code, it is inconvenient to use those bits on other architectures except powerpc. So transfer those section flags to enumeration to make it easy to add new section flags in the future. Also, move SECTION_TAINT_ZONE_DEVICE into the scope of CONFIG_ZONE_DEVICE to save a bit on non-zone-device case. [songmuchun@bytedance.com: replace enum with defines per David] Link: https://lkml.kernel.org/r/20220620110616.12056-2-songmuchun@bytedance.com Link: https://lkml.kernel.org/r/20220617135650.74901-1-songmuchun@bytedance.com Link: https://lkml.kernel.org/r/20220617135650.74901-2-songmuchun@bytedance.com Signed-off-by:
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Miaohe Lin authored
We might fail to isolate huge page due to e.g. the page is under migration which cleared HPageMigratable. We should return errno in this case rather than always return 1 which could confuse the user, i.e. the caller might think all of the memory is migrated while the hugetlb page is left behind. We make the prototype of isolate_huge_page consistent with isolate_lru_page as suggested by Huang Ying and rename isolate_huge_page to isolate_hugetlb as suggested by Muchun to improve the readability. Link: https://lkml.kernel.org/r/20220530113016.16663-4-linmiaohe@huawei.com Fixes: e8db67eb ("mm: migrate: move_pages() supports thp migration") Signed-off-by:
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- Jun 16, 2022
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Anshuman Khandual authored
In check_pfn_span(), a 'reason' string is being used to recreate the caller function name, while printing the warning message. It is really unnecessary as the warning message could just be printed inside the caller depending on the return code. Currently there are just two callers for check_pfn_span() i.e __add_pages() and __remove_pages(). Let's clean this up. Link: https://lkml.kernel.org/r/20220531090441.170650-1-anshuman.khandual@arm.com Signed-off-by:
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- May 13, 2022
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Muchun Song authored
We must add hugetlb_free_vmemmap=on (or "off") to the boot cmdline and reboot the server to enable or disable the feature of optimizing vmemmap pages associated with HugeTLB pages. However, rebooting usually takes a long time. So add a sysctl to enable or disable the feature at runtime without rebooting. Why we need this? There are 3 use cases. 1) The feature of minimizing overhead of struct page associated with each HugeTLB is disabled by default without passing "hugetlb_free_vmemmap=on" to the boot cmdline. When we (ByteDance) deliver the servers to the users who want to enable this feature, they have to configure the grub (change boot cmdline) and reboot the servers, whereas rebooting usually takes a long time (we have thousands of servers). It's a very bad experience for the users. So we need a approach to enable this feature after rebooting. This is a use case in our practical environment. 2) Some use cases are that HugeTLB pages are allocated 'on the fly' instead of being pulled from the HugeTLB pool, those workloads would be affected with this feature enabled. Those workloads could be identified by the characteristics of they never explicitly allocating huge pages with 'nr_hugepages' but only set 'nr_overcommit_hugepages' and then let the pages be allocated from the buddy allocator at fault time. We can confirm it is a real use case from the commit 099730d6. For those workloads, the page fault time could be ~2x slower than before. We suspect those users want to disable this feature if the system has enabled this before and they don't think the memory savings benefit is enough to make up for the performance drop. 3) If the workload which wants vmemmap pages to be optimized and the workload which wants to set 'nr_overcommit_hugepages' and does not want the extera overhead at fault time when the overcommitted pages be allocated from the buddy allocator are deployed in the same server. The user could enable this feature and set 'nr_hugepages' and 'nr_overcommit_hugepages', then disable the feature. In this case, the overcommited HugeTLB pages will not encounter the extra overhead at fault time. Link: https://lkml.kernel.org/r/20220512041142.39501-5-songmuchun@bytedance.com Signed-off-by:
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Muchun Song authored
Optimizing HugeTLB vmemmap pages is not compatible with allocating memmap on hot added memory. If "hugetlb_free_vmemmap=on" and memory_hotplug.memmap_on_memory" are both passed on the kernel command line, optimizing hugetlb pages takes precedence. However, the global variable memmap_on_memory will still be set to 1, even though we will not try to allocate memmap on hot added memory. Also introduce mhp_memmap_on_memory() helper to move the definition of "memmap_on_memory" to the scope of CONFIG_MHP_MEMMAP_ON_MEMORY. In the next patch, mhp_memmap_on_memory() will also be exported to be used in hugetlb_vmemmap.c. Link: https://lkml.kernel.org/r/20220512041142.39501-3-songmuchun@bytedance.com Signed-off-by:
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Zi Yan authored
alloc_contig_range() worked at MAX_ORDER_NR_PAGES granularity to avoid merging pageblocks with different migratetypes. It might unnecessarily convert extra pageblocks at the beginning and at the end of the range. Change alloc_contig_range() to work at pageblock granularity. Special handling is needed for free pages and in-use pages across the boundaries of the range specified by alloc_contig_range(). Because these= Partially isolated pages causes free page accounting issues. The free pages will be split and freed into separate migratetype lists; the in-use= Pages will be migrated then the freed pages will be handled in the aforementioned way. [ziy@nvidia.com: fix deadlock/crash] Link: https://lkml.kernel.org/r/23A7297E-6C84-4138-A9FE-3598234004E6@nvidia.com Link: https://lkml.kernel.org/r/20220425143118.2850746-4-zi.yan@sent.com Signed-off-by:
kernel test robot <lkp@intel.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David Hildenbrand <david@redhat.com> Cc: Eric Ren <renzhengeek@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
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liusongtang authored
pgprot.pgprot is non-portable code. It should be replaced by portable macro pgprot_val. Link: https://lkml.kernel.org/r/20220426071302.220646-1-liusongtang@huawei.com Signed-off-by:
liusongtang <liusongtang@huawei.com> Reviewed-by:
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