Changes in sysfs-kernel-mm-cma

bbfd5594756011167b8f8de9a00e0c946afda1e6 - Merge drm/drm-next into drm-intel-gt-next

Wed, 28 May 2025 09:20:17 +0200

Merge drm/drm-next into drm-intel-gt-nextNeed to pull in a67221b5eb8d ("drm/i915/dp: Return min bpc supported by source instead of 0")in order to fix build breakage on GCC 9.4.0 (from Ubuntu 20.04).Signed-off-by: Joonas Lahtinen List of files: /linux/Documentation/ABI/testing/sysfs-kernel-mm-cma

db5302ae571beec635c1a96e7f72926a4e65195e - Merge drm/drm-next into drm-intel-next

Fri, 16 May 2025 09:22:36 +0200

Merge drm/drm-next into drm-intel-nextBackmerge to sync with v6.15-rc, xe, and specifically async flip changesin drm-misc.Signed-off-by: Jani Nikula List of files: /linux/Documentation/ABI/testing/sysfs-kernel-mm-cma

4f9786035f9e519db41375818e1d0b5f20da2f10 - Merge branch 'next' into for-linus

Mon, 02 Jun 2025 06:41:07 +0200

Merge branch 'next' into for-linusPrepare input updates for 6.16 merge window. List of files: /linux/Documentation/ABI/testing/sysfs-kernel-mm-cma

d51b9d81f7883f526b26e3ab903e646274aebeb1 - Merge tag 'v6.15-rc6' into next

Fri, 16 May 2025 01:20:39 +0200

Merge tag 'v6.15-rc6' into nextSync up with mainline to bring in xpad controller changes. List of files: /linux/Documentation/ABI/testing/sysfs-kernel-mm-cma

844e31bbaef7c8a6ff2c0fbac45c0c85b5484482 - Merge remote-tracking branch 'drm-misc/drm-misc-next' into msm-next

Tue, 29 Apr 2025 22:42:29 +0200

Merge remote-tracking branch 'drm-misc/drm-misc-next' into msm-nextMerge drm-misc-next to get commit Fixes: fec450ca15af ("drm/display:hdmi: provide central data authority for ACR params").Signed-off-by: Rob Clark List of files: /linux/Documentation/ABI/testing/sysfs-kernel-mm-cma

3ab7ae8e07f888f223027f0ef84d33e43919ad55 - Merge drm/drm-next into drm-xe-next

Thu, 24 Apr 2025 13:34:55 +0200

Merge drm/drm-next into drm-xe-nextBackmerge to bring in linux 6.15-rc.Signed-off-by: Thomas Hellström List of files: /linux/Documentation/ABI/testing/sysfs-kernel-mm-cma

1afba39f9305fe4061a4e70baa6ebab9d41459da - Merge drm/drm-next into drm-misc-next

Mon, 07 Apr 2025 13:47:40 +0200

Merge drm/drm-next into drm-misc-nextBackmerging to get v6.15-rc1 into drm-misc-next. Also fixes abuild issue when enabling CONFIG_DRM_SCHED_KUNIT_TEST.Signed-off-by: Thomas Zimmermann List of files: /linux/Documentation/ABI/testing/sysfs-kernel-mm-cma

9f13acb2406a3aed90c6738b3a2f1c0e43118cbd - Merge tag 'v6.15-rc1' into x86/cpu, to refresh the branch with upstream changes

Fri, 11 Apr 2025 11:13:27 +0200

Merge tag 'v6.15-rc1' into x86/cpu, to refresh the branch with upstream changesSigned-off-by: Ingo Molnar List of files: /linux/Documentation/ABI/testing/sysfs-kernel-mm-cma

78a84fbfa4ffc4bb6e95560a909b2ac3efa0aad2 - Merge tag 'v6.15-rc1' into x86/mm, to pick up fixes

Wed, 09 Apr 2025 22:00:25 +0200

Merge tag 'v6.15-rc1' into x86/mm, to pick up fixesSigned-off-by: Ingo Molnar List of files: /linux/Documentation/ABI/testing/sysfs-kernel-mm-cma

6ce0fdaae043803bb324d915ce0fe43316bf1e81 - Merge tag 'v6.15-rc1' into x86/asm, to refresh the branch

Wed, 09 Apr 2025 21:39:43 +0200

Merge tag 'v6.15-rc1' into x86/asm, to refresh the branchSigned-off-by: Ingo Molnar List of files: /linux/Documentation/ABI/testing/sysfs-kernel-mm-cma

1260ed77798502de9c98020040d2995008de10cc - Merge drm/drm-fixes into drm-misc-fixes

Tue, 08 Apr 2025 10:15:47 +0200

Merge drm/drm-fixes into drm-misc-fixesBackmerging to get updates from v6.15-rc1.Signed-off-by: Thomas Zimmermann List of files: /linux/Documentation/ABI/testing/sysfs-kernel-mm-cma

eb0ece16027f8223d5dc9aaf90124f70577bd22a - Merge tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Tue, 01 Apr 2025 18:29:18 +0200

Merge tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mmPull MM updates from Andrew Morton: - The series "Enable strict percpu address space checks" from Uros Bizjak uses x86 named address space qualifiers to provide compile-time checking of percpu area accesses. This has caused a small amount of fallout - two or three issues were reported. In all cases the calling code was found to be incorrect. - The series "Some cleanup for memcg" from Chen Ridong implements some relatively monir cleanups for the memcontrol code. - The series "mm: fixes for device-exclusive entries (hmm)" from David Hildenbrand fixes a boatload of issues which David found then using device-exclusive PTE entries when THP is enabled. More work is needed, but this makes thins better - our own HMM selftests now succeed. - The series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed remove the z3fold and zbud implementations. They have been deprecated for half a year and nobody has complained. - The series "mm: further simplify VMA merge operation" from Lorenzo Stoakes implements numerous simplifications in this area. No runtime effects are anticipated. - The series "mm/madvise: remove redundant mmap_lock operations from process_madvise()" from SeongJae Park rationalizes the locking in the madvise() implementation. Performance gains of 20-25% were observed in one MADV_DONTNEED microbenchmark. - The series "Tiny cleanup and improvements about SWAP code" from Baoquan He contains a number of touchups to issues which Baoquan noticed when working on the swap code. - The series "mm: kmemleak: Usability improvements" from Catalin Marinas implements a couple of improvements to the kmemleak user-visible output. - The series "mm/damon/paddr: fix large folios access and schemes handling" from Usama Arif provides a couple of fixes for DAMON's handling of large folios. - The series "mm/damon/core: fix wrong and/or useless damos_walk() behaviors" from SeongJae Park fixes a few issues with the accuracy of kdamond's walking of DAMON regions. - The series "expose mapping wrprotect, fix fb_defio use" from Lorenzo Stoakes changes the interaction between framebuffer deferred-io and core MM. No functional changes are anticipated - this is preparatory work for the future removal of page structure fields. - The series "mm/damon: add support for hugepage_size DAMOS filter" from Usama Arif adds a DAMOS filter which permits the filtering by huge page sizes. - The series "mm: permit guard regions for file-backed/shmem mappings" from Lorenzo Stoakes extends the guard region feature from its present "anon mappings only" state. The feature now covers shmem and file-backed mappings. - The series "mm: batched unmap lazyfree large folios during reclamation" from Barry Song cleans up and speeds up the unmapping for pte-mapped large folios. - The series "reimplement per-vma lock as a refcount" from Suren Baghdasaryan puts the vm_lock back into the vma. Our reasons for pulling it out were largely bogus and that change made the code more messy. This patchset provides small (0-10%) improvements on one microbenchmark. - The series "Docs/mm/damon: misc DAMOS filters documentation fixes and improves" from SeongJae Park does some maintenance work on the DAMON docs. - The series "hugetlb/CMA improvements for large systems" from Frank van der Linden addresses a pile of issues which have been observed when using CMA on large machines. - The series "mm/damon: introduce DAMOS filter type for unmapped pages" from SeongJae Park enables users of DMAON/DAMOS to filter my the page's mapped/unmapped status. - The series "zsmalloc/zram: there be preemption" from Sergey Senozhatsky teaches zram to run its compression and decompression operations preemptibly. - The series "selftests/mm: Some cleanups from trying to run them" from Brendan Jackman fixes a pile of unrelated issues which Brendan encountered while runnimg our selftests. - The series "fs/proc/task_mmu: add guard region bit to pagemap" from Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to determine whether a particular page is a guard page. - The series "mm, swap: remove swap slot cache" from Kairui Song removes the swap slot cache from the allocation path - it simply wasn't being effective. - The series "mm: cleanups for device-exclusive entries (hmm)" from David Hildenbrand implements a number of unrelated cleanups in this code. - The series "mm: Rework generic PTDUMP configs" from Anshuman Khandual implements a number of preparatoty cleanups to the GENERIC_PTDUMP Kconfig logic. - The series "mm/damon: auto-tune aggregation interval" from SeongJae Park implements a feedback-driven automatic tuning feature for DAMON's aggregation interval tuning. - The series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in powerpc, sparc and x86 lazy MMU implementations. Ryan did this in preparation for implementing lazy mmu mode for arm64 to optimize vmalloc. - The series "mm/page_alloc: Some clarifications for migratetype fallback" from Brendan Jackman reworks some commentary to make the code easier to follow. - The series "page_counter cleanup and size reduction" from Shakeel Butt cleans up the page_counter code and fixes a size increase which we accidentally added late last year. - The series "Add a command line option that enables control of how many threads should be used to allocate huge pages" from Thomas Prescher does that. It allows the careful operator to significantly reduce boot time by tuning the parallalization of huge page initialization. - The series "Fix calculations in trace_balance_dirty_pages() for cgwb" from Tang Yizhou fixes the tracing output from the dirty page balancing code. - The series "mm/damon: make allow filters after reject filters useful and intuitive" from SeongJae Park improves the handling of allow and reject filters. Behaviour is made more consistent and the documention is updated accordingly. - The series "Switch zswap to object read/write APIs" from Yosry Ahmed updates zswap to the new object read/write APIs and thus permits the removal of some legacy code from zpool and zsmalloc. - The series "Some trivial cleanups for shmem" from Baolin Wang does as it claims. - The series "fs/dax: Fix ZONE_DEVICE page reference counts" from Alistair Popple regularizes the weird ZONE_DEVICE page refcount handling in DAX, permittig the removal of a number of special-case checks. - The series "refactor mremap and fix bug" from Lorenzo Stoakes is a preparatoty refactoring and cleanup of the mremap() code. - The series "mm: MM owner tracking for large folios (!hugetlb) + CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in which we determine whether a large folio is known to be mapped exclusively into a single MM. - The series "mm/damon: add sysfs dirs for managing DAMOS filters based on handling layers" from SeongJae Park adds a couple of new sysfs directories to ease the management of DAMON/DAMOS filters. - The series "arch, mm: reduce code duplication in mem_init()" from Mike Rapoport consolidates many per-arch implementations of mem_init() into code generic code, where that is practical. - The series "mm/damon/sysfs: commit parameters online via damon_call()" from SeongJae Park continues the cleaning up of sysfs access to DAMON internal data. - The series "mm: page_ext: Introduce new iteration API" from Luiz Capitulino reworks the page_ext initialization to fix a boot-time crash which was observed with an unusual combination of compile and cmdline options. - The series "Buddy allocator like (or non-uniform) folio split" from Zi Yan reworks the code to split a folio into smaller folios. The main benefit is lessened memory consumption: fewer post-split folios are generated. - The series "Minimize xa_node allocation during xarry split" from Zi Yan reduces the number of xarray xa_nodes which are generated during an xarray split. - The series "drivers/base/memory: Two cleanups" from Gavin Shan performs some maintenance work on the drivers/base/memory code. - The series "Add tracepoints for lowmem reserves, watermarks and totalreserve_pages" from Martin Liu adds some more tracepoints to the page allocator code. - The series "mm/madvise: cleanup requests validations and classifications" from SeongJae Park cleans up some warts which SeongJae observed during his earlier madvise work. - The series "mm/hwpoison: Fix regressions in memory failure handling" from Shuai Xue addresses two quite serious regressions which Shuai has observed in the memory-failure implementation. - The series "mm: reliable huge page allocator" from Johannes Weiner makes huge page allocations cheaper and more reliable by reducing fragmentation. - The series "Minor memcg cleanups & prep for memdescs" from Matthew Wilcox is preparatory work for the future implementation of memdescs. - The series "track memory used by balloon drivers" from Nico Pache introduces a way to track memory used by our various balloon drivers. - The series "mm/damon: introduce DAMOS filter type for active pages" from Nhat Pham permits users to filter for active/inactive pages, separately for file and anon pages. - The series "Adding Proactive Memory Reclaim Statistics" from Hao Jia separates the proactive reclaim statistics from the direct reclaim statistics. - The series "mm/vmscan: don't try to reclaim hwpoison folio" from Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim code.* tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits) mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex() x86/mm: restore early initialization of high_memory for 32-bits mm/vmscan: don't try to reclaim hwpoison folio mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper cgroup: docs: add pswpin and pswpout items in cgroup v2 doc mm: vmscan: split proactive reclaim statistics from direct reclaim statistics selftests/mm: speed up split_huge_page_test selftests/mm: uffd-unit-tests support for hugepages > 2M docs/mm/damon/design: document active DAMOS filter type mm/damon: implement a new DAMOS filter type for active pages fs/dax: don't disassociate zero page entries MM documentation: add "Unaccepted" meminfo entry selftests/mm: add commentary about 9pfs bugs fork: use __vmalloc_node() for stack allocation docs/mm: Physical Memory: Populate the "Zones" section xen: balloon: update the NR_BALLOON_PAGES state hv_balloon: update the NR_BALLOON_PAGES state balloon_compaction: update the NR_BALLOON_PAGES state meminfo: add a per node counter for balloon drivers mm: remove references to folio in __memcg_kmem_uncharge_page() ... List of files: /linux/Documentation/ABI/testing/sysfs-kernel-mm-cma

7365ff2c8eef4ea50b5f3ae2349fa180e3782ef1 - mm/cma: export total and free number of pages for CMA areas

Fri, 28 Feb 2025 19:29:02 +0100

mm/cma: export total and free number of pages for CMA areasPatch series "hugetlb/CMA improvements for large systems", v5.On large systems, we observed some issues with hugetlb and CMA:1) When specifying a large number of hugetlb boot pages (hugepages= on the commandline), the kernel may run out of memory before it even gets to HVO. For example, if you have a 3072G system, and want to use 3024 1G hugetlb pages for VMs, that should leave you plenty of space for the hypervisor, provided you have the hugetlb vmemmap optimization (HVO) enabled. However, since the vmemmap pages are always allocated first, and then later in boot freed, you will actually run yourself out of memory before you can do HVO. This means not getting all the hugetlb pages you want, and worse, failure to boot if there is an allocation failure in the system from which it can't recover.2) There is a system setup where you might want to use hugetlb_cma with a large value (say, again, 3024 out of 3072G like above), and then lower that if system usage allows it, to make room for non-hugetlb processes. For this, a variation of the problem above applies: the kernel runs out of unmovable space to allocate from before you finish boot, since your CMA area takes up all the space.3) CMA wants to use one big contiguous area for allocations. Which fails if you have the aforementioned 3T system with a gap in the middle of physical memory (like the < 40bits BIOS DMA area seen on some AMD systems). You then won't be able to set up a CMA area for one of the NUMA nodes, leading to loss of half of your hugetlb CMA area.4) Under the scenario mentioned in 2), when trying to grow the number of hugetlb pages after dropping it for a while, new CMA allocations may fail occasionally. This is not unexpected, some transient references on pages may prevent cma_alloc from succeeding under memory pressure. However, the hugetlb code then falls back to a normal contiguous alloc, which may end up succeeding. This is not always desired behavior. If you have a large CMA area, then the kernel has a restricted amount of memory it can do unmovable allocations from (a well known issue). A normal contiguous alloc may eat further in to this space.To resolve these issues, do the following:* Add hooks to the section init code to do custom initialization of memmap pages. Hugetlb bootmem (memblock) allocated pages can then be pre-HVOed. This avoids allocating a large number of vmemmap pages early in boot, only to have them be freed again later, and also avoids running out of memory as described under 1). Using these hooks for hugetlb is optional. It requires moving hugetlb bootmem allocation to an earlier spot by the architecture. This has been enabled on x86.* hugetlb_cma doesn't care about the CMA area it uses being one large contiguous range. Multiple smaller ranges are fine. The only requirements are that the areas should be on one NUMA node, and individual gigantic pages should be allocatable from them. So, implement multi-range support for CMA, avoiding issue 3).* Introduce a hugetlb_cma_only option on the commandline. This only allows allocations from CMA for gigantic pages, if hugetlb_cma= is also specified.* With hugetlb_cma_only active, it also makes sense to be able to pre-allocate gigantic hugetlb pages at boot time from the CMA area(s). Add a rudimentary early CMA allocation interface, that just grabs a piece of memblock-allocated space from the CMA area, which gets marked as allocated in the CMA bitmap when the CMA area is initialized. With this, hugepages= can be supported with hugetlb_cma=, making scenario 2) work.Additionally, fix some minor bugs, with one worth mentioning: sincehugetlb gigantic bootmem pages are allocated by memblock, they may spanmultiple zones, as memblock doesn't (and mostly can't) know about zones. This can cause problems. A hugetlb page spanning multiple zones is bad,and it's worse with HVO, when the de-HVO step effectively sneakilyre-assigns pages to a different zone than originally configured, since thetail pages all inherit the zone from the first 60 tail pages. Thiscondition is not common, but can be easily reproduced using ZONE_MOVABLE. To fix this, add checks to see if gigantic bootmem pages intersect withmultiple zones, and do not use them if they do, giving them back to thepage allocator instead.The first patch is kind of along for the ride, except that maintaining anavailable_count for a CMA area is convenient for the multiple rangesupport.This patch (of 27):In addition to the number of allocations and releases, system managementsoftware may like to be aware of the size of CMA areas, and how many pagesare available in it. This information is currently not available, soexport it in total_page and available_pages, respectively.The name 'available_pages' was picked over 'free_pages' because 'free'implies that the pages are unused. But they might not be, they justhaven't been used by cma_allocThe number of available pages is tracked regardless of CONFIG_CMA_SYSFS,allowing for a few minor shortcuts in the code, avoiding bitmapoperations.Link: https://lkml.kernel.org/r/20250228182928.2645936-2-fvdl@google.comSigned-off-by: Frank van der Linden Reviewed-by: Oscar Salvador Cc: David Hildenbrand Cc: Joao Martins Cc: Muchun Song Cc: Roman Gushchin (Cruise) Cc: Usama Arif Cc: Yu Zhao Cc: Zi Yan Cc: Alexander Gordeev Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Dan Carpenter Cc: Dave Hansen Cc: Heiko Carstens Cc: Johannes Weiner Cc: Madhavan Srinivasan Cc: Michael Ellerman Cc: Peter Zijlstra Cc: Vasily Gorbik Signed-off-by: Andrew Morton List of files: /linux/Documentation/ABI/testing/sysfs-kernel-mm-cma

a23e1966932464e1c5226cb9ac4ce1d5fc10ba22 - Merge branch 'next' into for-linus

Mon, 15 Jul 2024 23:03:44 +0200

Merge branch 'next' into for-linusPrepare input updates for 6.11 merge window. List of files: /linux/Documentation/ABI/testing/sysfs-kernel-mm-cma

6f47c7ae8c7afaf9ad291d39f0d3974f191a7946 - Merge tag 'v6.9' into next

Tue, 28 May 2024 06:37:18 +0200

Merge tag 'v6.9' into nextSync up with the mainline to bring in the new cleanup API. List of files: /linux/Documentation/ABI/testing/sysfs-kernel-mm-cma

60a2f25de7b8b785baee2932db932ae9a5b8c86d - Merge drm/drm-next into drm-intel-gt-next

Thu, 16 May 2024 09:33:01 +0200

Merge drm/drm-next into drm-intel-gt-nextSome display refactoring patches are needed in order to allow conflict-less merging.Signed-off-by: Tvrtko Ursulin List of files: /linux/Documentation/ABI/testing/sysfs-kernel-mm-cma

594ce0b8a998aa4d05827cd7c0d0dcec9a1e3ae2 - Merge topic branches 'clkdev' and 'fixes' into for-linus

Mon, 10 Jun 2024 13:03:21 +0200

Merge topic branches 'clkdev' and 'fixes' into for-linus List of files: /linux/Documentation/ABI/testing/sysfs-kernel-mm-cma

79790b6818e96c58fe2bffee1b418c16e64e7b80 - Merge drm/drm-next into drm-xe-next

Fri, 12 Apr 2024 15:14:25 +0200

Merge drm/drm-next into drm-xe-nextBackmerging drm-next in order to get up-to-date and in particularto access commit 9ca5facd0400f610f3f7f71aeb7fc0b949a48c67.Signed-off-by: Thomas Hellström List of files: /linux/Documentation/ABI/testing/sysfs-kernel-mm-cma

3e5a516f3bf1a33f2bf219f570e9b5c031616f6a - Merge tag 'phy_dp_modes_6.10' into msm-next-lumag

Mon, 08 Apr 2024 17:35:51 +0200

Merge tag 'phy_dp_modes_6.10' into msm-next-lumagMerge DisplayPort subnode API in order to allow DisplayPort driver toconfigure the PHYs either to the DP or eDP mode, depending on hardwareconfiguration.Signed-off-by: Dmitry Baryshkov List of files: /linux/Documentation/ABI/testing/sysfs-kernel-mm-cma

5add703f6acad1c63f8a532b6de56e50d548e904 - Merge drm/drm-next into drm-intel-next

Tue, 02 Apr 2024 14:17:13 +0200

Merge drm/drm-next into drm-intel-nextCatching up on 6.9-rc2Signed-off-by: Rodrigo Vivi List of files: /linux/Documentation/ABI/testing/sysfs-kernel-mm-cma