aboutsummaryrefslogtreecommitdiff
path: root/Documentation/core-api
AgeCommit message (Collapse)AuthorFilesLines
2022-10-25overflow: Fix kern-doc markup for functionsGravatar Kees Cook 1-0/+6
Fix the kern-doc markings for several of the overflow helpers and move their location into the core kernel API documentation, where it belongs (it's not driver-specific). Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: linux-hardening@vger.kernel.org Reviewed-by: Akira Yokosawa <akiyks@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2022-10-10Merge tag 'mm-stable-2022-10-08' of ↵Gravatar Linus Torvalds 3-3/+218
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in linux-next for a couple of months without, to my knowledge, any negative reports (or any positive ones, come to that). - Also the Maple Tree from Liam Howlett. An overlapping range-based tree for vmas. It it apparently slightly more efficient in its own right, but is mainly targeted at enabling work to reduce mmap_lock contention. Liam has identified a number of other tree users in the kernel which could be beneficially onverted to mapletrees. Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat at [1]. This has yet to be addressed due to Liam's unfortunately timed vacation. He is now back and we'll get this fixed up. - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses clang-generated instrumentation to detect used-unintialized bugs down to the single bit level. KMSAN keeps finding bugs. New ones, as well as the legacy ones. - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of memory into THPs. - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support file/shmem-backed pages. - userfaultfd updates from Axel Rasmussen - zsmalloc cleanups from Alexey Romanov - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure - Huang Ying adds enhancements to NUMA balancing memory tiering mode's page promotion, with a new way of detecting hot pages. - memcg updates from Shakeel Butt: charging optimizations and reduced memory consumption. - memcg cleanups from Kairui Song. - memcg fixes and cleanups from Johannes Weiner. - Vishal Moola provides more folio conversions - Zhang Yi removed ll_rw_block() :( - migration enhancements from Peter Xu - migration error-path bugfixes from Huang Ying - Aneesh Kumar added ability for a device driver to alter the memory tiering promotion paths. For optimizations by PMEM drivers, DRM drivers, etc. - vma merging improvements from Jakub Matěn. - NUMA hinting cleanups from David Hildenbrand. - xu xin added aditional userspace visibility into KSM merging activity. - THP & KSM code consolidation from Qi Zheng. - more folio work from Matthew Wilcox. - KASAN updates from Andrey Konovalov. - DAMON cleanups from Kaixu Xia. - DAMON work from SeongJae Park: fixes, cleanups. - hugetlb sysfs cleanups from Muchun Song. - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core. Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1] * tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits) hugetlb: allocate vma lock for all sharable vmas hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer hugetlb: fix vma lock handling during split vma and range unmapping mglru: mm/vmscan.c: fix imprecise comments mm/mglru: don't sync disk for each aging cycle mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol mm: memcontrol: use do_memsw_account() in a few more places mm: memcontrol: deprecate swapaccounting=0 mode mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled mm/secretmem: remove reduntant return value mm/hugetlb: add available_huge_pages() func mm: remove unused inline functions from include/linux/mm_inline.h selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd selftests/vm: add thp collapse shmem testing selftests/vm: add thp collapse file and tmpfs testing selftests/vm: modularize thp collapse memory operations selftests/vm: dedup THP helpers mm/khugepaged: add tracepoint to hpage_collapse_scan_file() mm/madvise: add file and shmem support to MADV_COLLAPSE ...
2022-10-03Merge tag 'rust-v6.1-rc1' of https://github.com/Rust-for-Linux/linuxGravatar Linus Torvalds 1-0/+10
Pull Rust introductory support from Kees Cook: "The tree has a recent base, but has fundamentally been in linux-next for a year and a half[1]. It's been updated based on feedback from the Kernel Maintainer's Summit, and to gain recent Reviewed-by: tags. Miguel is the primary maintainer, with me helping where needed/wanted. Our plan is for the tree to switch to the standard non-rebasing practice once this initial infrastructure series lands. The contents are the absolute minimum to get Rust code building in the kernel, with many more interfaces[2] (and drivers - NVMe[3], 9p[4], M1 GPU[5]) on the way. The initial support of Rust-for-Linux comes in roughly 4 areas: - Kernel internals (kallsyms expansion for Rust symbols, %pA format) - Kbuild infrastructure (Rust build rules and support scripts) - Rust crates and bindings for initial minimum viable build - Rust kernel documentation and samples Rust support has been in linux-next for a year and a half now, and the short log doesn't do justice to the number of people who have contributed both to the Linux kernel side but also to the upstream Rust side to support the kernel's needs. Thanks to these 173 people, and many more, who have been involved in all kinds of ways: Miguel Ojeda, Wedson Almeida Filho, Alex Gaynor, Boqun Feng, Gary Guo, Björn Roy Baron, Andreas Hindborg, Adam Bratschi-Kaye, Benno Lossin, Maciej Falkowski, Finn Behrens, Sven Van Asbroeck, Asahi Lina, FUJITA Tomonori, John Baublitz, Wei Liu, Geoffrey Thomas, Philip Herron, Arthur Cohen, David Faust, Antoni Boucher, Philip Li, Yujie Liu, Jonathan Corbet, Greg Kroah-Hartman, Paul E. McKenney, Josh Triplett, Kent Overstreet, David Gow, Alice Ryhl, Robin Randhawa, Kees Cook, Nick Desaulniers, Matthew Wilcox, Linus Walleij, Joe Perches, Michael Ellerman, Petr Mladek, Masahiro Yamada, Arnaldo Carvalho de Melo, Andrii Nakryiko, Konstantin Shelekhin, Rasmus Villemoes, Konstantin Ryabitsev, Stephen Rothwell, Andy Shevchenko, Sergey Senozhatsky, John Paul Adrian Glaubitz, David Laight, Nathan Chancellor, Jonathan Cameron, Daniel Latypov, Shuah Khan, Brendan Higgins, Julia Lawall, Laurent Pinchart, Geert Uytterhoeven, Akira Yokosawa, Pavel Machek, David S. Miller, John Hawley, James Bottomley, Arnd Bergmann, Christian Brauner, Dan Robertson, Nicholas Piggin, Zhouyi Zhou, Elena Zannoni, Jose E. Marchesi, Leon Romanovsky, Will Deacon, Richard Weinberger, Randy Dunlap, Paolo Bonzini, Roland Dreier, Mark Brown, Sasha Levin, Ted Ts'o, Steven Rostedt, Jarkko Sakkinen, Michal Kubecek, Marco Elver, Al Viro, Keith Busch, Johannes Berg, Jan Kara, David Sterba, Connor Kuehl, Andy Lutomirski, Andrew Lunn, Alexandre Belloni, Peter Zijlstra, Russell King, Eric W. Biederman, Willy Tarreau, Christoph Hellwig, Emilio Cobos Álvarez, Christian Poveda, Mark Rousskov, John Ericson, TennyZhuang, Xuanwo, Daniel Paoliello, Manish Goregaokar, comex, Josh Stone, Stephan Sokolow, Philipp Krones, Guillaume Gomez, Joshua Nelson, Mats Larsen, Marc Poulhiès, Samantha Miller, Esteban Blanc, Martin Schmidt, Martin Rodriguez Reboredo, Daniel Xu, Viresh Kumar, Bartosz Golaszewski, Vegard Nossum, Milan Landaverde, Dariusz Sosnowski, Yuki Okushi, Matthew Bakhtiari, Wu XiangCheng, Tiago Lam, Boris-Chengbiao Zhou, Sumera Priyadarsini, Viktor Garske, Niklas Mohrin, Nándor István Krácser, Morgan Bartlett, Miguel Cano, Léo Lanteri Thauvin, Julian Merkle, Andreas Reindl, Jiapeng Chong, Fox Chen, Douglas Su, Antonio Terceiro, SeongJae Park, Sergio González Collado, Ngo Iok Ui (Wu Yu Wei), Joshua Abraham, Milan, Daniel Kolsoi, ahomescu, Manas, Luis Gerhorst, Li Hongyu, Philipp Gesang, Russell Currey, Jalil David Salamé Messina, Jon Olson, Raghvender, Angelos, Kaviraj Kanagaraj, Paul Römer, Sladyn Nunes, Mauro Baladés, Hsiang-Cheng Yang, Abhik Jain, Hongyu Li, Sean Nash, Yuheng Su, Peng Hao, Anhad Singh, Roel Kluin, Sara Saa, Geert Stappers, Garrett LeSage, IFo Hancroft, and Linus Torvalds" Link: https://lwn.net/Articles/849849/ [1] Link: https://github.com/Rust-for-Linux/linux/commits/rust [2] Link: https://github.com/metaspace/rust-linux/commit/d88c3744d6cbdf11767e08bad56cbfb67c4c96d0 [3] Link: https://github.com/wedsonaf/linux/commit/9367032607f7670de0ba1537cf09ab0f4365a338 [4] Link: https://github.com/AsahiLinux/linux/commits/gpu/rust-wip [5] * tag 'rust-v6.1-rc1' of https://github.com/Rust-for-Linux/linux: (27 commits) MAINTAINERS: Rust samples: add first Rust examples x86: enable initial Rust support docs: add Rust documentation Kbuild: add Rust support rust: add `.rustfmt.toml` scripts: add `is_rust_module.sh` scripts: add `rust_is_available.sh` scripts: add `generate_rust_target.rs` scripts: add `generate_rust_analyzer.py` scripts: decode_stacktrace: demangle Rust symbols scripts: checkpatch: enable language-independent checks for Rust scripts: checkpatch: diagnose uses of `%pA` in the C side as errors vsprintf: add new `%pA` format specifier rust: export generated symbols rust: add `kernel` crate rust: add `bindings` crate rust: add `macros` crate rust: add `compiler_builtins` crate rust: adapt `alloc` crate to the kernel ...
2022-10-03mm/page_alloc: remove obsolete gfpflags_normal_context()Gravatar Miaohe Lin 1-3/+0
Since commit dacb5d8875cc ("tcp: fix page frag corruption on page fault"), there's no caller of gfpflags_normal_context(). Remove it as this helper is strictly tied to the sk page frag usage and there won't be other user in the future. [linmiaohe@huawei.com: fix htmldocs] Link: https://lkml.kernel.org/r/1bc55727-9b66-0e9e-c306-f10c4716ea89@huawei.com Link: https://lkml.kernel.org/r/20220916072257.9639-16-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-29docs: put atomic*.txt and memory-barriers.txt into the core-api bookGravatar Jonathan Corbet 4-0/+58
These files describe part of the core API, but have never been converted to RST due to ... let's say local oppposition. So, create a set of special-purpose wrappers to ..include these files into a separate page so that they can be a part of the htmldocs build. Then link them into the core-api manual and remove them from the "staging" dumping ground. Acked-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Reviewed-by: David Vernet <void@manifault.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20220927160559.97154-7-corbet@lwn.net Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-09-29docs: move asm-annotations.rst into core-apiGravatar Jonathan Corbet 2-0/+223
This one file should not really be in the top-level documentation directory. core-api/ may not be a perfect fit but seems to be best, so move it there. Adjust a couple of internal document references to make them location-independent, and point checkpatch.pl at the new location. Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Joe Perches <joe@perches.com> Reviewed-by: David Vernet <void@manifault.com> Acked-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Acked-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20220927160559.97154-6-corbet@lwn.net Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-09-28vsprintf: add new `%pA` format specifierGravatar Gary Guo 1-0/+10
This patch adds a format specifier `%pA` to `vsprintf` which formats a pointer as `core::fmt::Arguments`. Doing so allows us to directly format to the internal buffer of `printf`, so we do not have to use a temporary buffer on the stack to pre-assemble the message on the Rust side. This specifier is intended only to be used from Rust and not for C, so `checkpatch.pl` is intentionally unchanged to catch any misuse. Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com> Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com> Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com> Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com> Signed-off-by: Gary Guo <gary@garyguo.net> Co-developed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-27Remove duplicate words inside documentationGravatar Akhil Raj 1-1/+1
I have removed repeated `the` inside the documentation Signed-off-by: Akhil Raj <lf32.dev@gmail.com> Link: https://lore.kernel.org/r/20220827145359.32599-1-lf32.dev@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-09-26Maple Tree: add new data structureGravatar Liam R. Howlett 2-0/+218
Patch series "Introducing the Maple Tree" The maple tree is an RCU-safe range based B-tree designed to use modern processor cache efficiently. There are a number of places in the kernel that a non-overlapping range-based tree would be beneficial, especially one with a simple interface. If you use an rbtree with other data structures to improve performance or an interval tree to track non-overlapping ranges, then this is for you. The tree has a branching factor of 10 for non-leaf nodes and 16 for leaf nodes. With the increased branching factor, it is significantly shorter than the rbtree so it has fewer cache misses. The removal of the linked list between subsequent entries also reduces the cache misses and the need to pull in the previous and next VMA during many tree alterations. The first user that is covered in this patch set is the vm_area_struct, where three data structures are replaced by the maple tree: the augmented rbtree, the vma cache, and the linked list of VMAs in the mm_struct. The long term goal is to reduce or remove the mmap_lock contention. The plan is to get to the point where we use the maple tree in RCU mode. Readers will not block for writers. A single write operation will be allowed at a time. A reader re-walks if stale data is encountered. VMAs would be RCU enabled and this mode would be entered once multiple tasks are using the mm_struct. Davidlor said : Yes I like the maple tree, and at this stage I don't think we can ask for : more from this series wrt the MM - albeit there seems to still be some : folks reporting breakage. Fundamentally I see Liam's work to (re)move : complexity out of the MM (not to say that the actual maple tree is not : complex) by consolidating the three complimentary data structures very : much worth it considering performance does not take a hit. This was very : much a turn off with the range locking approach, which worst case scenario : incurred in prohibitive overhead. Also as Liam and Matthew have : mentioned, RCU opens up a lot of nice performance opportunities, and in : addition academia[1] has shown outstanding scalability of address spaces : with the foundation of replacing the locked rbtree with RCU aware trees. A similar work has been discovered in the academic press https://pdos.csail.mit.edu/papers/rcuvm:asplos12.pdf Sheer coincidence. We designed our tree with the intention of solving the hardest problem first. Upon settling on a b-tree variant and a rough outline, we researched ranged based b-trees and RCU b-trees and did find that article. So it was nice to find reassurances that we were on the right path, but our design choice of using ranges made that paper unusable for us. This patch (of 70): The maple tree is an RCU-safe range based B-tree designed to use modern processor cache efficiently. There are a number of places in the kernel that a non-overlapping range-based tree would be beneficial, especially one with a simple interface. If you use an rbtree with other data structures to improve performance or an interval tree to track non-overlapping ranges, then this is for you. The tree has a branching factor of 10 for non-leaf nodes and 16 for leaf nodes. With the increased branching factor, it is significantly shorter than the rbtree so it has fewer cache misses. The removal of the linked list between subsequent entries also reduces the cache misses and the need to pull in the previous and next VMA during many tree alterations. The first user that is covered in this patch set is the vm_area_struct, where three data structures are replaced by the maple tree: the augmented rbtree, the vma cache, and the linked list of VMAs in the mm_struct. The long term goal is to reduce or remove the mmap_lock contention. The plan is to get to the point where we use the maple tree in RCU mode. Readers will not block for writers. A single write operation will be allowed at a time. A reader re-walks if stale data is encountered. VMAs would be RCU enabled and this mode would be entered once multiple tasks are using the mm_struct. There is additional BUG_ON() calls added within the tree, most of which are in debug code. These will be replaced with a WARN_ON() call in the future. There is also additional BUG_ON() calls within the code which will also be reduced in number at a later date. These exist to catch things such as out-of-range accesses which would crash anyways. Link: https://lkml.kernel.org/r/20220906194824.2110408-1-Liam.Howlett@oracle.com Link: https://lkml.kernel.org/r/20220906194824.2110408-2-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Tested-by: David Howells <dhowells@redhat.com> Tested-by: Sven Schnelle <svens@linux.ibm.com> Tested-by: Yu Zhao <yuzhao@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: David Hildenbrand <david@redhat.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: SeongJae Park <sj@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-18Documentation: irqdomain: Fix typo of "at least once"Gravatar Eric Lin 1-1/+1
Signed-off-by: Eric Lin <dslin1010@gmail.com> Link: https://lore.kernel.org/r/20220811091516.2107908-1-dslin1010@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-08-07Merge tag 'bitmap-6.0-rc1' of https://github.com/norov/linuxGravatar Linus Torvalds 1-4/+4
Pull bitmap updates from Yury Norov: - fix the duplicated comments on bitmap_to_arr64() (Qu Wenruo) - optimize out non-atomic bitops on compile-time constants (Alexander Lobakin) - cleanup bitmap-related headers (Yury Norov) - x86/olpc: fix 'logical not is only applied to the left hand side' (Alexander Lobakin) - lib/nodemask: inline wrappers around bitmap (Yury Norov) * tag 'bitmap-6.0-rc1' of https://github.com/norov/linux: (26 commits) lib/nodemask: inline next_node_in() and node_random() powerpc: drop dependency on <asm/machdep.h> in archrandom.h x86/olpc: fix 'logical not is only applied to the left hand side' lib/cpumask: move some one-line wrappers to header file headers/deps: mm: align MANITAINERS and Docs with new gfp.h structure headers/deps: mm: Split <linux/gfp_types.h> out of <linux/gfp.h> headers/deps: mm: Optimize <linux/gfp.h> header dependencies lib/cpumask: move trivial wrappers around find_bit to the header lib/cpumask: change return types to unsigned where appropriate cpumask: change return types to bool where appropriate lib/bitmap: change type of bitmap_weight to unsigned long lib/bitmap: change return types to bool where appropriate arm: align find_bit declarations with generic kernel iommu/vt-d: avoid invalid memory access via node_online(NUMA_NO_NODE) lib/test_bitmap: test the tail after bitmap_to_arr64() lib/bitmap: fix off-by-one in bitmap_to_arr64() lib: test_bitmap: add compile-time optimization/evaluations assertions bitmap: don't assume compiler evaluates small mem*() builtins calls net/ice: fix initializing the bitmap in the switch code bitops: let optimize out non-atomic bitops on compile-time constants ...
2022-08-06Merge tag 'dma-mapping-5.20-2022-08-06' of ↵Gravatar Linus Torvalds 1-0/+14
git://git.infradead.org/users/hch/dma-mapping Pull dma-mapping updates from Christoph Hellwig: - convert arm32 to the common dma-direct code (Arnd Bergmann, Robin Murphy, Christoph Hellwig) - restructure the PCIe peer to peer mapping support (Logan Gunthorpe) - allow the IOMMU code to communicate an optional DMA mapping length and use that in scsi and libata (John Garry) - split the global swiotlb lock (Tianyu Lan) - various fixes and cleanup (Chao Gao, Dan Carpenter, Dongli Zhang, Lukas Bulwahn, Robin Murphy) * tag 'dma-mapping-5.20-2022-08-06' of git://git.infradead.org/users/hch/dma-mapping: (45 commits) swiotlb: fix passing local variable to debugfs_create_ulong() dma-mapping: reformat comment to suppress htmldoc warning PCI/P2PDMA: Remove pci_p2pdma_[un]map_sg() RDMA/rw: drop pci_p2pdma_[un]map_sg() RDMA/core: introduce ib_dma_pci_p2p_dma_supported() nvme-pci: convert to using dma_map_sgtable() nvme-pci: check DMA ops when indicating support for PCI P2PDMA iommu/dma: support PCI P2PDMA pages in dma-iommu map_sg iommu: Explicitly skip bus address marked segments in __iommu_map_sg() dma-mapping: add flags to dma_map_ops to indicate PCI P2PDMA support dma-direct: support PCI P2PDMA pages in dma-direct map_sg dma-mapping: allow EREMOTEIO return code for P2PDMA transfers PCI/P2PDMA: Introduce helpers for dma_map_sg implementations PCI/P2PDMA: Attempt to set map_type if it has not been set lib/scatterlist: add flag for indicating P2PDMA segments in an SGL swiotlb: clean up some coding style and minor issues dma-mapping: update comment after dmabounce removal scsi: sd: Add a comment about limiting max_sectors to shost optimal limit ata: libata-scsi: cap ata_device->max_sectors according to shost->max_sectors scsi: scsi_transport_sas: cap shost opt_sectors according to DMA optimal limit ...
2022-08-05Merge tag 'mm-stable-2022-08-03' of ↵Gravatar Linus Torvalds 1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "Most of the MM queue. A few things are still pending. Liam's maple tree rework didn't make it. This has resulted in a few other minor patch series being held over for next time. Multi-gen LRU still isn't merged as we were waiting for mapletree to stabilize. The current plan is to merge MGLRU into -mm soon and to later reintroduce mapletree, with a view to hopefully getting both into 6.1-rc1. Summary: - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe Lin, Yang Shi, Anshuman Khandual and Mike Rapoport - Some kmemleak fixes from Patrick Wang and Waiman Long - DAMON updates from SeongJae Park - memcg debug/visibility work from Roman Gushchin - vmalloc speedup from Uladzislau Rezki - more folio conversion work from Matthew Wilcox - enhancements for coherent device memory mapping from Alex Sierra - addition of shared pages tracking and CoW support for fsdax, from Shiyang Ruan - hugetlb optimizations from Mike Kravetz - Mel Gorman has contributed some pagealloc changes to improve latency and realtime behaviour. - mprotect soft-dirty checking has been improved by Peter Xu - Many other singleton patches all over the place" [ XFS merge from hell as per Darrick Wong in https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ] * tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits) tools/testing/selftests/vm/hmm-tests.c: fix build mm: Kconfig: fix typo mm: memory-failure: convert to pr_fmt() mm: use is_zone_movable_page() helper hugetlbfs: fix inaccurate comment in hugetlbfs_statfs() hugetlbfs: cleanup some comments in inode.c hugetlbfs: remove unneeded header file hugetlbfs: remove unneeded hugetlbfs_ops forward declaration hugetlbfs: use helper macro SZ_1{K,M} mm: cleanup is_highmem() mm/hmm: add a test for cross device private faults selftests: add soft-dirty into run_vmtests.sh selftests: soft-dirty: add test for mprotect mm/mprotect: fix soft-dirty check in can_change_pte_writable() mm: memcontrol: fix potential oom_lock recursion deadlock mm/gup.c: fix formatting in check_and_migrate_movable_page() xfs: fail dax mount if reflink is enabled on a partition mm/memcontrol.c: remove the redundant updating of stats_flush_threshold userfaultfd: don't fail on unrecognized features hugetlb_cgroup: fix wrong hugetlb cgroup numa stat ...
2022-08-05Merge tag 'asm-generic-6.0' of ↵Gravatar Linus Torvalds 3-235/+0
git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic Pull asm-generic updates from Arnd Bergmann: "There are three independent sets of changes: - Sai Prakash Ranjan adds tracing support to the asm-generic version of the MMIO accessors, which is intended to help understand problems with device drivers and has been part of Qualcomm's vendor kernels for many years - A patch from Sebastian Siewior to rework the handling of IRQ stacks in softirqs across architectures, which is needed for enabling PREEMPT_RT - The last patch to remove the CONFIG_VIRT_TO_BUS option and some of the code behind that, after the last users of this old interface made it in through the netdev, scsi, media and staging trees" * tag 'asm-generic-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: uapi: asm-generic: fcntl: Fix typo 'the the' in comment arch/*/: remove CONFIG_VIRT_TO_BUS soc: qcom: geni: Disable MMIO tracing for GENI SE serial: qcom_geni_serial: Disable MMIO tracing for geni serial asm-generic/io: Add logging support for MMIO accessors KVM: arm64: Add a flag to disable MMIO trace for nVHE KVM lib: Add register read/write tracing support drm/meson: Fix overflow implicit truncation warnings irqchip/tegra: Fix overflow implicit truncation warnings coresight: etm4x: Use asm-generic IO memory barriers arm64: io: Use asm-generic high level MMIO accessors arch/*: Disable softirq stacks on PREEMPT_RT.
2022-08-03Merge tag 'xarray-6.0' of git://git.infradead.org/users/willy/xarrayGravatar Linus Torvalds 1-0/+3
Pull XArray/IDR updates from Matthew Wilcox: - Add appropriate might_alloc() annotations to the XArray APIs - Document that the IDR is deprecated * tag 'xarray-6.0' of git://git.infradead.org/users/willy/xarray: IDR: Note that the IDR API is deprecated XArray: Add calls to might_alloc()
2022-08-01Merge tag 'x86_mm_for_v6.0_rc1' of ↵Gravatar Linus Torvalds 1-23/+21
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm updates from Borislav Petkov: - Rename a PKRU macro to make more sense when reading the code - Update pkeys documentation - Avoid reading contended mm's TLB generation var if not absolutely necessary along with fixing a case where arch_tlbbatch_flush() doesn't adhere to the generation scheme and thus violates the conditions for the above avoidance. * tag 'x86_mm_for_v6.0_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm/tlb: Ignore f->new_tlb_gen when zero x86/pkeys: Clarify PKRU_AD_KEY macro Documentation/protection-keys: Clean up documentation for User Space pkeys x86/mm/tlb: Avoid reading mm_tlb_gen when possible
2022-07-19dma-mapping: add dma_opt_mapping_size()Gravatar John Garry 1-0/+14
Streaming DMA mapping involving an IOMMU may be much slower for larger total mapping size. This is because every IOMMU DMA mapping requires an IOVA to be allocated and freed. IOVA sizes above a certain limit are not cached, which can have a big impact on DMA mapping performance. Provide an API for device drivers to know this "optimal" limit, such that they may try to produce mapping which don't exceed it. Signed-off-by: John Garry <john.garry@huawei.com> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2022-07-15headers/deps: mm: align MANITAINERS and Docs with new gfp.h structureGravatar Yury Norov 1-4/+4
After moving gfp types out of gfp.h, we have to align MAINTAINERS and Docs, to avoid warnings like this: >> include/linux/gfp.h:1: warning: 'Page mobility and placement hints' not found >> include/linux/gfp.h:1: warning: 'Watermark modifiers' not found >> include/linux/gfp.h:1: warning: 'Reclaim modifiers' not found >> include/linux/gfp.h:1: warning: 'Useful GFP flag combinations' not found Signed-off-by: Yury Norov <yury.norov@gmail.com>
2022-07-10IDR: Note that the IDR API is deprecatedGravatar Matthew Wilcox (Oracle) 1-0/+3
Some people read the documentation, perhaps. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-07-01doc: module: update file referencesGravatar Masahiro Yamada 2-3/+3
Adjust documents to the file moves made by commit cfc1d277891e ("module: Move all into module/"). Thanks to Yanteng Si for helping me to update Documentation/translations/zh_CN/core-api/kernel-api.rst Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Yanteng Si <siyanteng@loongson.cn> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-06-28arch/*/: remove CONFIG_VIRT_TO_BUSGravatar Arnd Bergmann 3-235/+0
All architecture-independent users of virt_to_bus() and bus_to_virt() have been fixed to use the dma mapping interfaces or have been removed now. This means the definitions on most architectures, and the CONFIG_VIRT_TO_BUS symbol are now obsolete and can be removed. The only exceptions to this are a few network and scsi drivers for m68k Amiga and VME machines and ppc32 Macintosh. These drivers work correctly with the old interfaces and are probably not worth changing. On alpha and parisc, virt_to_bus() were still used in asm/floppy.h. alpha can use isa_virt_to_bus() like x86 does, and parisc can just open-code the virt_to_phys() here, as this is architecture specific code. I tried updating the bus-virt-phys-mapping.rst documentation, which started as an email from Linus to explain some details of the Linux-2.0 driver interfaces. The bits about virt_to_bus() were declared obsolete backin 2000, and the rest is not all that relevant any more, so in the end I just decided to remove the file completely. Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Acked-by: Helge Deller <deller@gmx.de> # parisc Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2022-06-27docs: rename Documentation/vm to Documentation/mmGravatar Mike Rapoport 1-1/+1
so it will be consistent with code mm directory and with Documentation/admin-guide/mm and won't be confused with virtual machines. Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Suggested-by: Matthew Wilcox <willy@infradead.org> Tested-by: Ira Weiny <ira.weiny@intel.com> Acked-by: Jonathan Corbet <corbet@lwn.net> Acked-by: Wu XiangCheng <bobwxc@email.cn>
2022-06-07Documentation/protection-keys: Clean up documentation for User Space pkeysGravatar Ira Weiny 1-23/+21
The documentation for user space pkeys was a bit dated including things such as Amazon and distribution testing information which is irrelevant now. Update the documentation. This also streamlines adding the Supervisor pkey documentation later on. Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lkml.kernel.org/r/20220419170649.1022246-2-ira.weiny@intel.com
2022-05-25Merge tag 'docs-5.19' of git://git.lwn.net/linuxGravatar Linus Torvalds 2-0/+344
Pull documentation updates from Jonathan Corbet: "It was a moderately busy cycle for documentation; highlights include: - After a long period of inactivity, the Japanese translations are seeing some much-needed maintenance and updating. - Reworked IOMMU documentation - Some new documentation for static-analysis tools - A new overall structure for the memory-management documentation. This is an LSFMM outcome that, it is hoped, will help encourage developers to fill in the many gaps. Optimism is eternal...but hopefully it will work. - More Chinese translations. Plus the usual typo fixes, updates, etc" * tag 'docs-5.19' of git://git.lwn.net/linux: (70 commits) docs: pdfdocs: Add space for chapter counts >= 100 in TOC docs/zh_CN: Add dev-tools/gdb-kernel-debugging.rst Chinese translation input: Docs: correct ntrig.rst typo input: Docs: correct atarikbd.rst typos MAINTAINERS: Become the docs/zh_CN maintainer docs/zh_CN: fix devicetree usage-model translation mm,doc: Add new documentation structure Documentation: drop more IDE boot options and ide-cd.rst Documentation/process: use scripts/get_maintainer.pl on patches MAINTAINERS: Add entry for DOCUMENTATION/JAPANESE docs/trans/ja_JP/howto: Don't mention specific kernel versions docs/ja_JP/SubmittingPatches: Request summaries for commit references docs/ja_JP/SubmittingPatches: Add Suggested-by as a standard signature docs/ja_JP/SubmittingPatches: Randy has moved docs/ja_JP/SubmittingPatches: Suggest the use of scripts/get_maintainer.pl docs/ja_JP/SubmittingPatches: Update GregKH links Documentation/sysctl: document max_rcu_stall_to_panic Documentation: add missing angle bracket in cgroup-v2 doc Documentation: dev-tools: use literal block instead of code-block docs/zh_CN: add vm numa translation ...
2022-05-25Merge tag 'printk-for-5.19' of ↵Gravatar Linus Torvalds 2-0/+138
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk updates from Petr Mladek: - Offload writing printk() messages on consoles to per-console kthreads. It prevents soft-lockups when an extensive amount of messages is printed. It was observed, for example, during boot of large systems with a lot of peripherals like disks or network interfaces. It prevents live-lockups that were observed, for example, when messages about allocation failures were reported and a CPU handled consoles instead of reclaiming the memory. It was hard to solve even with rate limiting because it would need to take into account the amount of messages and the speed of all consoles. It is a must to have for real time. Otherwise, any printk() might break latency guarantees. The per-console kthreads allow to handle each console on its own speed. Slow consoles do not longer slow down faster ones. And printk() does not longer unpredictably slows down various code paths. There are situations when the kthreads are either not available or not reliable, for example, early boot, suspend, or panic. In these situations, printk() uses the legacy mode and tries to handle consoles immediately. - Add documentation for the printk index. * tag 'printk-for-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: printk, tracing: fix console tracepoint printk: remove @console_locked printk: extend console_lock for per-console locking printk: add kthread console printers printk: add functions to prefer direct printing printk: add pr_flush() printk: move buffer definitions into console_emit_next_record() caller printk: refactor and rework printing logic printk: add con_printk() macro for console details printk: call boot_delay_msec() in printk_delay() printk: get caller_id/timestamp after migration disable printk: wake waiters for safe and NMI contexts printk: wake up all waiters printk: add missing memory barrier to wake_up_klogd() printk: cpu sync always disable interrupts printk: rename cpulock functions printk/index: Printk index feature documentation MAINTAINERS: Add printk indexing maintainers on mention of printk_index
2022-04-22Documentation: move watch_queue to core-apiGravatar Randy Dunlap 2-0/+344
Move watch_queue documentation to the core-api index and subdirectory. Fixes: c73be61cede5 ("pipe: Add general notification queue support") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: David Howells <dhowells@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-04-14timekeeping: Introduce fast accessor to clock taiGravatar Kurt Kanzenbach 1-0/+1
Introduce fast/NMI safe accessor to clock tai for tracing. The Linux kernel tracing infrastructure has support for using different clocks to generate timestamps for trace events. Especially in TSN networks it's useful to have TAI as trace clock, because the application scheduling is done in accordance to the network time, which is based on TAI. With a tai trace_clock in place, it becomes very convenient to correlate network activity with Linux kernel application traces. Use the same implementation as ktime_get_boot_fast_ns() does by reading the monotonic time and adding the TAI offset. The same limitations as for the fast boot implementation apply. The TAI offset may change at run time e.g., by setting the time or using adjtimex() with an offset. However, these kind of offset changes are rare events. Nevertheless, the user has to be aware and deal with it in post processing. An alternative approach would be to use the same implementation as ktime_get_real_fast_ns() does. However, this requires to add an additional u64 member to the tk_read_base struct. This struct together with a seqcount is designed to fit into a single cache line on 64 bit architectures. Adding a new member would violate this constraint. Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20220414091805.89667-2-kurt@linutronix.de
2022-04-13printk/index: Printk index feature documentationGravatar Petr Mladek 2-0/+138
Document the printk index feature. The primary motivation is to explain that it is not creating KABI from particular printk() calls. Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: Chris Down <chris@chrisdown.name> Signed-off-by: Petr Mladek <pmladek@suse.com>
2022-04-01Merge tag 'xarray-5.18' of git://git.infradead.org/users/willy/xarrayGravatar Linus Torvalds 1-5/+9
Pull XArray updates from Matthew Wilcox: - Documentation update - Fix test-suite build after move of bitmap.h - Fix xas_create_range() when a large entry is already present - Fix xas_split() of a shadow entry * tag 'xarray-5.18' of git://git.infradead.org/users/willy/xarray: XArray: Update the LRU list in xas_split() XArray: Fix xas_create_range() when multi-order entry present XArray: Include bitmap.h from xarray.h XArray: Document the locking requirement for the xa_state
2022-03-28Reinstate some of "swiotlb: rework "fix info leak with DMA_FROM_DEVICE""Gravatar Linus Torvalds 1-8/+0
Halil Pasic points out [1] that the full revert of that commit (revert in bddac7c1e02b), and that a partial revert that only reverts the problematic case, but still keeps some of the cleanups is probably better.  And that partial revert [2] had already been verified by Oleksandr Natalenko to also fix the issue, I had just missed that in the long discussion. So let's reinstate the cleanups from commit aa6f8dcbab47 ("swiotlb: rework "fix info leak with DMA_FROM_DEVICE""), and effectively only revert the part that caused problems. Link: https://lore.kernel.org/all/20220328013731.017ae3e3.pasic@linux.ibm.com/ [1] Link: https://lore.kernel.org/all/20220324055732.GB12078@lst.de/ [2] Link: https://lore.kernel.org/all/4386660.LvFx2qVVIh@natalenko.name/ [3] Suggested-by: Halil Pasic <pasic@linux.ibm.com> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Cc: Christoph Hellwig" <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-26Revert "swiotlb: rework "fix info leak with DMA_FROM_DEVICE""Gravatar Linus Torvalds 1-0/+8
This reverts commit aa6f8dcbab473f3a3c7454b74caa46d36cdc5d13. It turns out this breaks at least the ath9k wireless driver, and possibly others. What the ath9k driver does on packet receive is to set up the DMA transfer with: int ath_rx_init(..) .. bf->bf_buf_addr = dma_map_single(sc->dev, skb->data, common->rx_bufsize, DMA_FROM_DEVICE); and then the receive logic (through ath_rx_tasklet()) will fetch incoming packets static bool ath_edma_get_buffers(..) .. dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr, common->rx_bufsize, DMA_FROM_DEVICE); ret = ath9k_hw_process_rxdesc_edma(ah, rs, skb->data); if (ret == -EINPROGRESS) { /*let device gain the buffer again*/ dma_sync_single_for_device(sc->dev, bf->bf_buf_addr, common->rx_bufsize, DMA_FROM_DEVICE); return false; } and it's worth noting how that first DMA sync: dma_sync_single_for_cpu(..DMA_FROM_DEVICE); is there to make sure the CPU can read the DMA buffer (possibly by copying it from the bounce buffer area, or by doing some cache flush). The iommu correctly turns that into a "copy from bounce bufer" so that the driver can look at the state of the packets. In the meantime, the device may continue to write to the DMA buffer, but we at least have a snapshot of the state due to that first DMA sync. But that _second_ DMA sync: dma_sync_single_for_device(..DMA_FROM_DEVICE); is telling the DMA mapping that the CPU wasn't interested in the area because the packet wasn't there. In the case of a DMA bounce buffer, that is a no-op. Note how it's not a sync for the CPU (the "for_device()" part), and it's not a sync for data written by the CPU (the "DMA_FROM_DEVICE" part). Or rather, it _should_ be a no-op. That's what commit aa6f8dcbab47 broke: it made the code bounce the buffer unconditionally, and changed the DMA_FROM_DEVICE to just unconditionally and illogically be DMA_TO_DEVICE. [ Side note: purely within the confines of the swiotlb driver it wasn't entirely illogical: The reason it did that odd DMA_FROM_DEVICE -> DMA_TO_DEVICE conversion thing is because inside the swiotlb driver, it uses just a swiotlb_bounce() helper that doesn't care about the whole distinction of who the sync is for - only which direction to bounce. So it took the "sync for device" to mean that the CPU must have been the one writing, and thought it meant DMA_TO_DEVICE. ] Also note how the commentary in that commit was wrong, probably due to that whole confusion, claiming that the commit makes the swiotlb code "bounce unconditionally (that is, also when dir == DMA_TO_DEVICE) in order do avoid synchronising back stale data from the swiotlb buffer" which is nonsensical for two reasons: - that "also when dir == DMA_TO_DEVICE" is nonsensical, as that was exactly when it always did - and should do - the bounce. - since this is a sync for the device (not for the CPU), we're clearly fundamentally not coping back stale data from the bounce buffers at all, because we'd be copying *to* the bounce buffers. So that commit was just very confused. It confused the direction of the synchronization (to the device, not the cpu) with the direction of the DMA (from the device). Reported-and-bisected-by: Oleksandr Natalenko <oleksandr@natalenko.name> Reported-by: Olha Cherevyk <olha.cherevyk@gmail.com> Cc: Halil Pasic <pasic@linux.ibm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Kalle Valo <kvalo@kernel.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Toke Høiland-Jørgensen <toke@toke.dk> Cc: Maxime Bizon <mbizon@freebox.fr> Cc: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22Merge tag 'folio-5.18c' of git://git.infradead.org/users/willy/pagecacheGravatar Linus Torvalds 1-9/+9
Pull folio updates from Matthew Wilcox: - Rewrite how munlock works to massively reduce the contention on i_mmap_rwsem (Hugh Dickins): https://lore.kernel.org/linux-mm/8e4356d-9622-a7f0-b2c-f116b5f2efea@google.com/ - Sort out the page refcount mess for ZONE_DEVICE pages (Christoph Hellwig): https://lore.kernel.org/linux-mm/20220210072828.2930359-1-hch@lst.de/ - Convert GUP to use folios and make pincount available for order-1 pages. (Matthew Wilcox) - Convert a few more truncation functions to use folios (Matthew Wilcox) - Convert page_vma_mapped_walk to use PFNs instead of pages (Matthew Wilcox) - Convert rmap_walk to use folios (Matthew Wilcox) - Convert most of shrink_page_list() to use a folio (Matthew Wilcox) - Add support for creating large folios in readahead (Matthew Wilcox) * tag 'folio-5.18c' of git://git.infradead.org/users/willy/pagecache: (114 commits) mm/damon: minor cleanup for damon_pa_young selftests/vm/transhuge-stress: Support file-backed PMD folios mm/filemap: Support VM_HUGEPAGE for file mappings mm/readahead: Switch to page_cache_ra_order mm/readahead: Align file mappings for non-DAX mm/readahead: Add large folio readahead mm: Support arbitrary THP sizes mm: Make large folios depend on THP mm: Fix READ_ONLY_THP warning mm/filemap: Allow large folios to be added to the page cache mm: Turn can_split_huge_page() into can_split_folio() mm/vmscan: Convert pageout() to take a folio mm/vmscan: Turn page_check_references() into folio_check_references() mm/vmscan: Account large folios correctly mm/vmscan: Optimise shrink_page_list for non-PMD-sized folios mm/vmscan: Free non-shmem folios without splitting them mm/rmap: Constify the rmap_walk_control argument mm/rmap: Convert rmap_walk() to take a folio mm: Turn page_anon_vma() into folio_anon_vma() mm/rmap: Turn page_lock_anon_vma_read() into folio_lock_anon_vma_read() ...
2022-03-22Merge branch 'akpm' (patches from Andrew)Gravatar Linus Torvalds 1-2/+17
Merge updates from Andrew Morton: - A few misc subsystems: kthread, scripts, ntfs, ocfs2, block, and vfs - Most the MM patches which precede the patches in Willy's tree: kasan, pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap, sparsemem, vmalloc, pagealloc, memory-failure, mlock, hugetlb, userfaultfd, vmscan, compaction, mempolicy, oom-kill, migration, thp, cma, autonuma, psi, ksm, page-poison, madvise, memory-hotplug, rmap, zswap, uaccess, ioremap, highmem, cleanups, kfence, hmm, and damon. * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (227 commits) mm/damon/sysfs: remove repeat container_of() in damon_sysfs_kdamond_release() Docs/ABI/testing: add DAMON sysfs interface ABI document Docs/admin-guide/mm/damon/usage: document DAMON sysfs interface selftests/damon: add a test for DAMON sysfs interface mm/damon/sysfs: support DAMOS stats mm/damon/sysfs: support DAMOS watermarks mm/damon/sysfs: support schemes prioritization mm/damon/sysfs: support DAMOS quotas mm/damon/sysfs: support DAMON-based Operation Schemes mm/damon/sysfs: support the physical address space monitoring mm/damon/sysfs: link DAMON for virtual address spaces monitoring mm/damon: implement a minimal stub for sysfs-based DAMON interface mm/damon/core: add number of each enum type values mm/damon/core: allow non-exclusive DAMON start/stop Docs/damon: update outdated term 'regions update interval' Docs/vm/damon/design: update DAMON-Idle Page Tracking interference handling Docs/vm/damon: call low level monitoring primitives the operations mm/damon: remove unnecessary CONFIG_DAMON option mm/damon/paddr,vaddr: remove damon_{p,v}a_{target_valid,set_operations}() mm/damon/dbgfs-test: fix is_target_id() change ...
2022-03-22mm: document and polish read-ahead codeGravatar NeilBrown 1-2/+17
Add some "big-picture" documentation for read-ahead and polish the code to make it fit this documentation. The meaning of ->async_size is clarified to match its name. i.e. Any request to ->readahead() has a sync part and an async part. The caller will wait for the sync pages to complete, but will not wait for the async pages. The first async page is still marked PG_readahead Note that the current function names page_cache_sync_ra() and page_cache_async_ra() are misleading. All ra request are partly sync and partly async, so either part can be empty. A page_cache_sync_ra() request will usually set ->async_size non-zero, implying it is not all synchronous. When a non-zero req_count is passed to page_cache_async_ra(), the implication is that some prefix of the request is synchronous, though the calculation made there is incorrect - I haven't tried to fix it. Link: https://lkml.kernel.org/r/164549983734.9187.11586890887006601405.stgit@noble.brown Signed-off-by: NeilBrown <neilb@suse.de> Cc: Anna Schumaker <Anna.Schumaker@Netapp.com> Cc: Chao Yu <chao@kernel.org> Cc: Darrick J. Wong <djwong@kernel.org> Cc: Ilya Dryomov <idryomov@gmail.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jeff Layton <jlayton@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Lars Ellenberg <lars.ellenberg@linbit.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Paolo Valente <paolo.valente@linaro.org> Cc: Philipp Reisner <philipp.reisner@linbit.com> Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-21mm: Make compound_pincount always availableGravatar Matthew Wilcox (Oracle) 1-9/+9
Move compound_pincount from the third page to the second page, which means it's available for all compound pages. That lets us delete hpage_pincount_available(). On 32-bit systems, there isn't enough space for both compound_pincount and compound_nr in the second page (it would collide with page->private, which is in use for pages in the swap cache), so revert the optimisation of storing both compound_order and compound_nr on 32-bit systems. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-03-07swiotlb: rework "fix info leak with DMA_FROM_DEVICE"Gravatar Halil Pasic 1-8/+0
Unfortunately, we ended up merging an old version of the patch "fix info leak with DMA_FROM_DEVICE" instead of merging the latest one. Christoph (the swiotlb maintainer), he asked me to create an incremental fix (after I have pointed this out the mix up, and asked him for guidance). So here we go. The main differences between what we got and what was agreed are: * swiotlb_sync_single_for_device is also required to do an extra bounce * We decided not to introduce DMA_ATTR_OVERWRITE until we have exploiters * The implantation of DMA_ATTR_OVERWRITE is flawed: DMA_ATTR_OVERWRITE must take precedence over DMA_ATTR_SKIP_CPU_SYNC Thus this patch removes DMA_ATTR_OVERWRITE, and makes swiotlb_sync_single_for_device() bounce unconditionally (that is, also when dir == DMA_TO_DEVICE) in order do avoid synchronising back stale data from the swiotlb buffer. Let me note, that if the size used with dma_sync_* API is less than the size used with dma_[un]map_*, under certain circumstances we may still end up with swiotlb not being transparent. In that sense, this is no perfect fix either. To get this bullet proof, we would have to bounce the entire mapping/bounce buffer. For that we would have to figure out the starting address, and the size of the mapping in swiotlb_sync_single_for_device(). While this does seem possible, there seems to be no firm consensus on how things are supposed to work. Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Fixes: ddbd89deb7d3 ("swiotlb: fix info leak with DMA_FROM_DEVICE") Cc: stable@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-02-14swiotlb: fix info leak with DMA_FROM_DEVICEGravatar Halil Pasic 1-0/+8
The problem I'm addressing was discovered by the LTP test covering cve-2018-1000204. A short description of what happens follows: 1) The test case issues a command code 00 (TEST UNIT READY) via the SG_IO interface with: dxfer_len == 524288, dxdfer_dir == SG_DXFER_FROM_DEV and a corresponding dxferp. The peculiar thing about this is that TUR is not reading from the device. 2) In sg_start_req() the invocation of blk_rq_map_user() effectively bounces the user-space buffer. As if the device was to transfer into it. Since commit a45b599ad808 ("scsi: sg: allocate with __GFP_ZERO in sg_build_indirect()") we make sure this first bounce buffer is allocated with GFP_ZERO. 3) For the rest of the story we keep ignoring that we have a TUR, so the device won't touch the buffer we prepare as if the we had a DMA_FROM_DEVICE type of situation. My setup uses a virtio-scsi device and the buffer allocated by SG is mapped by the function virtqueue_add_split() which uses DMA_FROM_DEVICE for the "in" sgs (here scatter-gather and not scsi generics). This mapping involves bouncing via the swiotlb (we need swiotlb to do virtio in protected guest like s390 Secure Execution, or AMD SEV). 4) When the SCSI TUR is done, we first copy back the content of the second (that is swiotlb) bounce buffer (which most likely contains some previous IO data), to the first bounce buffer, which contains all zeros. Then we copy back the content of the first bounce buffer to the user-space buffer. 5) The test case detects that the buffer, which it zero-initialized, ain't all zeros and fails. One can argue that this is an swiotlb problem, because without swiotlb we leak all zeros, and the swiotlb should be transparent in a sense that it does not affect the outcome (if all other participants are well behaved). Copying the content of the original buffer into the swiotlb buffer is the only way I can think of to make swiotlb transparent in such scenarios. So let's do just that if in doubt, but allow the driver to tell us that the whole mapped buffer is going to be overwritten, in which case we can preserve the old behavior and avoid the performance impact of the extra bounce. Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2022-02-03XArray: Document the locking requirement for the xa_stateGravatar Matthew Wilcox (Oracle) 1-5/+9
It wasn't obvious to all readers that it's unsafe to reuse an xa_state after dropping the xas_lock() or the rcu_read_lock(). Reported-by: Charan Teja Kalla <charante@codeaurora.org> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-01-27Documentation: core-api: entry: Add comments about nestingGravatar Nicolas Saenz Julienne 1-0/+18
The topic of nesting and reentrancy in the context of early entry code hasn't been addressed so far. So do it. Signed-off-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/r/20220110105044.94423-2-nsaenzju@redhat.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-01-27Documentation: Fill the gaps about entry/noinstr constraintsGravatar Thomas Gleixner 2-0/+269
The entry/exit handling for exceptions, interrupts, syscalls and KVM is not really documented except for some comments. Fill the gaps. Signed-off-by: Thomas Gleixner <tglx@linutronix.de Co-developed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Signed-off-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> ---- Changes since v3: - s/nointr/noinstr/ Changes since v2: - No big content changes, just style corrections, so it should be pretty clean at this stage. In the light of this, I kept Mark's Reviewed-by. - Paul's style and paragraph re-writes - Randy's style comments - Add links to transition type sections Documentation/core-api/entry.rst | 261 +++++++++++++++++++++++++++++++ Documentation/core-api/index.rst | 8 + 2 files changed, 269 insertions(+) create mode 100644 Documentation/core-api/entry.rst Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20220110105044.94423-1-nsaenzju@redhat.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-01-12Merge tag 'iomap-5.17' of git://git.infradead.org/users/willy/linuxGravatar Linus Torvalds 1-0/+1
Pull iomap updates from Matthew Wilcox: "Convert xfs/iomap to use folios. This should be all that is needed for XFS to use large folios. There is no code in this pull request to create large folios, but no additional changes should be needed to XFS or iomap once they are created. Usually this would have come from Darrick, and we had intended that it would come that route. Between the holidays and various things which Darrick needed to work on, he asked if I could send things directly. There weren't any other iomap patches pending for this release, which probably also played a role" * tag 'iomap-5.17' of git://git.infradead.org/users/willy/linux: (26 commits) iomap: Inline __iomap_zero_iter into its caller xfs: Support large folios iomap: Support large folios in invalidatepage iomap: Convert iomap_migrate_page() to use folios iomap: Convert iomap_add_to_ioend() to take a folio iomap: Simplify iomap_do_writepage() iomap: Simplify iomap_writepage_map() iomap,xfs: Convert ->discard_page to ->discard_folio iomap: Convert iomap_write_end_inline to take a folio iomap: Convert iomap_write_begin() and iomap_write_end() to folios iomap: Convert __iomap_zero_iter to use a folio iomap: Allow iomap_write_begin() to be called with the full length iomap: Convert iomap_page_mkwrite to use a folio iomap: Convert readahead and readpage to use a folio iomap: Convert iomap_read_inline_data to take a folio iomap: Use folio offsets instead of page offsets iomap: Convert bio completions to use folios iomap: Pass the iomap_page into iomap_set_range_uptodate iomap: Add iomap_invalidate_folio iomap: Convert iomap_releasepage to use a folio ...
2022-01-12Merge tag 'driver-core-5.17-rc1' of ↵Gravatar Linus Torvalds 1-9/+7
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is the set of changes for the driver core for 5.17-rc1. Lots of little things here, including: - kobj_type cleanups - auxiliary_bus documentation updates - auxiliary_device conversions for some drivers (relevant subsystems all have provided acks for these) - kernfs lock contention reduction for some workloads - other tiny cleanups and changes. All of these have been in linux-next for a while with no reported issues" * tag 'driver-core-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (43 commits) kobject documentation: remove default_attrs information drivers/firmware: Add missing platform_device_put() in sysfb_create_simplefb debugfs: lockdown: Allow reading debugfs files that are not world readable driver core: Make bus notifiers in right order in really_probe() driver core: Move driver_sysfs_remove() after driver_sysfs_add() firmware: edd: remove empty default_attrs array firmware: dmi-sysfs: use default_groups in kobj_type qemu_fw_cfg: use default_groups in kobj_type firmware: memmap: use default_groups in kobj_type sh: sq: use default_groups in kobj_type headers/uninline: Uninline single-use function: kobject_has_children() devtmpfs: mount with noexec and nosuid driver core: Simplify async probe test code by using ktime_ms_delta() nilfs2: use default_groups in kobj_type kobject: remove kset from struct kset_uevent_ops callbacks driver core: make kobj_type constant. driver core: platform: document registration-failure requirement vdpa/mlx5: Use auxiliary_device driver data helpers net/mlx5e: Use auxiliary_device driver data helpers soundwire: intel: Use auxiliary_device driver data helpers ...
2022-01-07kobject documentation: remove default_attrs informationGravatar Greg Kroah-Hartman 1-3/+2
Since commit aa30f47cf666 ("kobject: Add support for default attribute groups to kobj_type") we have been encouraging the use of default_groups instead of default_attrs, so reflect that information in the documentation as well so that no new users get added while the kernel is converted over to not use this field anymore. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20220104105024.1014313-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-28kobject: remove kset from struct kset_uevent_ops callbacksGravatar Greg Kroah-Hartman 1-4/+3
There is no need to pass the pointer to the kset in the struct kset_uevent_ops callbacks as no one uses it, so just remove that pointer entirely. Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Wedson Almeida Filho <wedsonaf@google.com> Link: https://lore.kernel.org/r/20211227163924.3970661-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-27driver core: make kobj_type constant.Gravatar Wedson Almeida Filho 1-2/+2
This way instances of kobj_type (which contain function pointers) can be stored in .rodata, which means that they cannot be [easily/accidentally] modified at runtime. Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com> Link: https://lore.kernel.org/r/20211224231345.777370-1-wedsonaf@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-16block: Add bio_for_each_folio_all()Gravatar Matthew Wilcox (Oracle) 1-0/+1
Allow callers to iterate over each folio instead of each page. The bio need not have been constructed using folios originally. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2021-11-29block: remove blk-exec.cGravatar Christoph Hellwig 1-3/+0
All this code is tightly coupled to the blk-mq core, so move it there. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20211117061404.331732-4-hch@lst.de [axboe: remove doc generation for blk-exec.c] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-06Merge branch 'akpm' (patches from Andrew)Gravatar Linus Torvalds 1-3/+0
Merge misc updates from Andrew Morton: "257 patches. Subsystems affected by this patch series: scripts, ocfs2, vfs, and mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache, gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc, pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools, memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm, vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram, cleanups, kfence, and damon)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (257 commits) mm/damon: remove return value from before_terminate callback mm/damon: fix a few spelling mistakes in comments and a pr_debug message mm/damon: simplify stop mechanism Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions Docs/admin-guide/mm/damon/start: simplify the content Docs/admin-guide/mm/damon/start: fix a wrong link Docs/admin-guide/mm/damon/start: fix wrong example commands mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on mm/damon: remove unnecessary variable initialization Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM) selftests/damon: support watermarks mm/damon/dbgfs: support watermarks mm/damon/schemes: activate schemes based on a watermarks mechanism tools/selftests/damon: update for regions prioritization of schemes mm/damon/dbgfs: support prioritization weights mm/damon/vaddr,paddr: support pageout prioritization mm/damon/schemes: prioritize regions within the quotas mm/damon/selftests: support schemes quotas mm/damon/dbgfs: support quotas of schemes ...
2021-11-06mm/memory_hotplug: remove HIGHMEM leftoversGravatar David Hildenbrand 1-3/+0
We don't support CONFIG_MEMORY_HOTPLUG on 32 bit and consequently not HIGHMEM. Let's remove any leftover code -- including the unused "status_change_nid_high" field part of the memory notifier. Link: https://lkml.kernel.org/r/20210929143600.49379-5-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Alex Shi <alexs@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-02Merge branch 'for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqGravatar Linus Torvalds 1-4/+17
Pull workqueue updates from Tejun Heo: "Nothing too interesting. An optimization to short-circuit noop cpumask updates, debug dump code reorg, and doc update" * 'for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: doc: Call out the non-reentrance conditions workqueue: Introduce show_one_worker_pool and show_one_workqueue. workqueue: make sysfs of unbound kworker cpumask more clever