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2025-11-12init/main.c: wrap long kernel cmdline when printing to logsDouglas Anderson1-1/+96
The kernel cmdline length is allowed to be longer than what printk can handle. When this happens the cmdline that's printed to the kernel ring buffer at bootup is cutoff and some kernel cmdline options are "hidden" from the logs. This undercuts the usefulness of the log message. Specifically, grepping for COMMAND_LINE_SIZE shows that 2048 is common and some architectures even define it as 4096. s390 allows a CONFIG-based maximum up to 1MB (though it's not expected that anyone will go over the default max of 4096 [1]). The maximum message pr_notice() seems to be able to handle (based on experiment) is 1021 characters. This appears to be based on the current value of PRINTKRB_RECORD_MAX as 1024 and the fact that pr_notice() spends 2 characters on the loglevel prefix and we have a '\n' at the end. While it would be possible to increase the limits of printk() (and therefore pr_notice()) somewhat, it doesn't appear possible to increase it enough to fully include a 2048-character cmdline without breaking userspace. Specifically on at least two tested userspaces (ChromeOS plus the Debian-based distro I'm typing this message on) the `dmesg` tool reads lines from `/dev/kmsg` in 2047-byte chunks. As per `Documentation/ABI/testing/dev-kmsg`: Every read() from the opened device node receives one record of the kernel's printk buffer. ... Messages in the record ring buffer get overwritten as whole, there are never partial messages received by read(). We simply can't fit a 2048-byte cmdline plus the "Kernel command line:" prefix plus info about time/log_level/etc in a 2047-byte read. The above means that if we want to avoid the truncation we need to do some type of wrapping of the cmdline when printing. Add wrapping to the printout of the kernel command line. By default, the wrapping is set to 1021 characters to avoid breaking anyone, but allow wrapping to be set lower by a Kconfig knob "CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN". Any tools that are correctly parsing the cmdline today (because it is less than 1021 characters) will see no difference in their behavior. The format of wrapped output is designed to be matched by anyone using "grep" to search for the cmdline and also to be easy for tools to handle. Anyone who is sure their tools (if any) handle the wrapped format can choose a lower wrapping value and have prettier output. Setting CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN to 0 fully disables the wrapping logic. This means that long command lines will be truncated again, but this config could be set if command lines are expected to be long and userspace is known not to handle parsing logs with the wrapping. Wrapping is based on spaces, ignoring quotes. All lines are prefixed with "Kernel command line: " and lines that are not the last line have a " \" suffix added to them. The prefix and suffix count towards the line length for wrapping purposes. The ideal length will be exceeded if no appropriate place to wrap is found. The wrapping function added here is fairly generic and could be made a library function (somewhat like print_hex_dump()) if it's needed elsewhere in the kernel. However, having printk() directly incorporate this wrapping would be unlikely to be a good idea since it would break printouts into more than one record without any obvious common line prefix to tie lines together. It would also be extra overhead when, in general, kernel log message should simply be kept smaller than 1021 bytes. For some discussion on this topic, see responses to the v1 posting of this patch [2]. [akpm@linux-foundation.org: make print_kernel_cmdline __init] [dianders@chromium.org: v4] Link: https://lkml.kernel.org/r/20251027082204.v4.1.I095f1e2c6c27f9f4de0b4841f725f356c643a13f@changeid Link: https://lkml.kernel.org/r/20251023113257.v3.1.I095f1e2c6c27f9f4de0b4841f725f356c643a13f@changeid Link: https://lore.kernel.org/r/20251021131633.26700Dd6-hca@linux.ibm.com [1] Link: https://lore.kernel.org/r/CAD=FV=VNyt1zG_8pS64wgV8VkZWiWJymnZ-XCfkrfaAhhFSKcA@mail.gmail.com [2] Signed-off-by: Douglas Anderson <dianders@chromium.org> Tested-by: Paul E. McKenney <paulmck@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andrew Chant <achant@google.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Francesco Valla <francesco@valla.it> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: guoweikang <guoweikang.kernel@gmail.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Hendrik Farr <kernel@jfarr.cc> Cc: Jeff Xu <jeffxu@chromium.org> Cc: Kees Cook <kees@kernel.org> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-02Merge tag 'mm-nonmm-stable-2025-10-02-15-29' of ↵Linus Torvalds1-0/+12
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: - "ida: Remove the ida_simple_xxx() API" from Christophe Jaillet completes the removal of this legacy IDR API - "panic: introduce panic status function family" from Jinchao Wang provides a number of cleanups to the panic code and its various helpers, which were rather ad-hoc and scattered all over the place - "tools/delaytop: implement real-time keyboard interaction support" from Fan Yu adds a few nice user-facing usability changes to the delaytop monitoring tool - "efi: Fix EFI boot with kexec handover (KHO)" from Evangelos Petrongonas fixes a panic which was happening with the combination of EFI and KHO - "Squashfs: performance improvement and a sanity check" from Phillip Lougher teaches squashfs's lseek() about SEEK_DATA/SEEK_HOLE. A mere 150x speedup was measured for a well-chosen microbenchmark - plus another 50-odd singleton patches all over the place * tag 'mm-nonmm-stable-2025-10-02-15-29' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (75 commits) Squashfs: reject negative file sizes in squashfs_read_inode() kallsyms: use kmalloc_array() instead of kmalloc() MAINTAINERS: update Sibi Sankar's email address Squashfs: add SEEK_DATA/SEEK_HOLE support Squashfs: add additional inode sanity checking lib/genalloc: fix device leak in of_gen_pool_get() panic: remove CONFIG_PANIC_ON_OOPS_VALUE ocfs2: fix double free in user_cluster_connect() checkpatch: suppress strscpy warnings for userspace tools cramfs: fix incorrect physical page address calculation kernel: prevent prctl(PR_SET_PDEATHSIG) from racing with parent process exit Squashfs: fix uninit-value in squashfs_get_parent kho: only fill kimage if KHO is finalized ocfs2: avoid extra calls to strlen() after ocfs2_sprintf_system_inode_name() kernel/sys.c: fix the racy usage of task_lock(tsk->group_leader) in sys_prlimit64() paths sched/task.h: fix the wrong comment on task_lock() nesting with tasklist_lock coccinelle: platform_no_drv_owner: handle also built-in drivers coccinelle: of_table: handle SPI device ID tables lib/decompress: use designated initializers for struct compress_format efi: support booting with kexec handover (KHO) ...
2025-09-29Merge tag 'namespace-6.18-rc1' of ↵Linus Torvalds1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull namespace updates from Christian Brauner: "This contains a larger set of changes around the generic namespace infrastructure of the kernel. Each specific namespace type (net, cgroup, mnt, ...) embedds a struct ns_common which carries the reference count of the namespace and so on. We open-coded and cargo-culted so many quirks for each namespace type that it just wasn't scalable anymore. So given there's a bunch of new changes coming in that area I've started cleaning all of this up. The core change is to make it possible to correctly initialize every namespace uniformly and derive the correct initialization settings from the type of the namespace such as namespace operations, namespace type and so on. This leaves the new ns_common_init() function with a single parameter which is the specific namespace type which derives the correct parameters statically. This also means the compiler will yell as soon as someone does something remotely fishy. The ns_common_init() addition also allows us to remove ns_alloc_inum() and drops any special-casing of the initial network namespace in the network namespace initialization code that Linus complained about. Another part is reworking the reference counting. The reference counting was open-coded and copy-pasted for each namespace type even though they all followed the same rules. This also removes all open accesses to the reference count and makes it private and only uses a very small set of dedicated helpers to manipulate them just like we do for e.g., files. In addition this generalizes the mount namespace iteration infrastructure introduced a few cycles ago. As reminder, the vfs makes it possible to iterate sequentially and bidirectionally through all mount namespaces on the system or all mount namespaces that the caller holds privilege over. This allow userspace to iterate over all mounts in all mount namespaces using the listmount() and statmount() system call. Each mount namespace has a unique identifier for the lifetime of the systems that is exposed to userspace. The network namespace also has a unique identifier working exactly the same way. This extends the concept to all other namespace types. The new nstree type makes it possible to lookup namespaces purely by their identifier and to walk the namespace list sequentially and bidirectionally for all namespace types, allowing userspace to iterate through all namespaces. Looking up namespaces in the namespace tree works completely locklessly. This also means we can move the mount namespace onto the generic infrastructure and remove a bunch of code and members from struct mnt_namespace itself. There's a bunch of stuff coming on top of this in the future but for now this uses the generic namespace tree to extend a concept introduced first for pidfs a few cycles ago. For a while now we have supported pidfs file handles for pidfds. This has proven to be very useful. This extends the concept to cover namespaces as well. It is possible to encode and decode namespace file handles using the common name_to_handle_at() and open_by_handle_at() apis. As with pidfs file handles, namespace file handles are exhaustive, meaning it is not required to actually hold a reference to nsfs in able to decode aka open_by_handle_at() a namespace file handle. Instead the FD_NSFS_ROOT constant can be passed which will let the kernel grab a reference to the root of nsfs internally and thus decode the file handle. Namespaces file descriptors can already be derived from pidfds which means they aren't subject to overmount protection bugs. IOW, it's irrelevant if the caller would not have access to an appropriate /proc/<pid>/ns/ directory as they could always just derive the namespace based on a pidfd already. It has the same advantage as pidfds. It's possible to reliably and for the lifetime of the system refer to a namespace without pinning any resources and to compare them trivially. Permission checking is kept simple. If the caller is located in the namespace the file handle refers to they are able to open it otherwise they must hold privilege over the owning namespace of the relevant namespace. The namespace file handle layout is exposed as uapi and has a stable and extensible format. For now it simply contains the namespace identifier, the namespace type, and the inode number. The stable format means that userspace may construct its own namespace file handles without going through name_to_handle_at() as they are already allowed for pidfs and cgroup file handles" * tag 'namespace-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (65 commits) ns: drop assert ns: move ns type into struct ns_common nstree: make struct ns_tree private ns: add ns_debug() ns: simplify ns_common_init() further cgroup: add missing ns_common include ns: use inode initializer for initial namespaces selftests/namespaces: verify initial namespace inode numbers ns: rename to __ns_ref nsfs: port to ns_ref_*() helpers net: port to ns_ref_*() helpers uts: port to ns_ref_*() helpers ipv4: use check_net() net: use check_net() net-sysfs: use check_net() user: port to ns_ref_*() helpers time: port to ns_ref_*() helpers pid: port to ns_ref_*() helpers ipc: port to ns_ref_*() helpers cgroup: port to ns_ref_*() helpers ...
2025-09-19time: support ns lookupChristian Brauner1-0/+2
Support the generic ns lookup infrastructure to support file handles for namespaces. Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-09-13init: handle bootloader identifier in kernel parametersHuacai Chen1-0/+12
BootLoaders (Grub, LILO, etc) may pass an identifier such as "BOOT_IMAGE= /boot/vmlinuz-x.y.z" to kernel parameters. But these identifiers are not recognized by the kernel itself so will be passed to userspace. However user space init program also don't recognize it. KEXEC/KDUMP (kexec-tools) may also pass an identifier such as "kexec" on some architectures. We cannot change BootLoader's behavior, because this behavior exists for many years, and there are already user space programs search BOOT_IMAGE= in /proc/cmdline to obtain the kernel image locations: https://github.com/linuxdeepin/deepin-ab-recovery/blob/master/util.go (search getBootOptions) https://github.com/linuxdeepin/deepin-ab-recovery/blob/master/main.go (search getKernelReleaseWithBootOption) So the the best way is handle (ignore) it by the kernel itself, which can avoid such boot warnings (if we use something like init=/bin/bash, bootloader identifier can even cause a crash): Kernel command line: BOOT_IMAGE=(hd0,1)/vmlinuz-6.x root=/dev/sda3 ro console=tty Unknown kernel command line parameters "BOOT_IMAGE=(hd0,1)/vmlinuz-6.x", will be passed to user space. [chenhuacai@loongson.cn: use strstarts()] Link: https://lkml.kernel.org/r/20250815090120.1569947-1-chenhuacai@loongson.cn Link: https://lkml.kernel.org/r/20250721101343.3283480-1-chenhuacai@loongson.cn Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-03init/main.c: fix boot time tracing crashMike Rapoport (Microsoft)1-1/+1
Steven Rostedt reported a crash with "ftrace=function" kernel command line: [ 0.159269] BUG: kernel NULL pointer dereference, address: 000000000000001c [ 0.160254] #PF: supervisor read access in kernel mode [ 0.160975] #PF: error_code(0x0000) - not-present page [ 0.161697] PGD 0 P4D 0 [ 0.162055] Oops: Oops: 0000 [#1] SMP PTI [ 0.162619] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.17.0-rc2-test-00006-g48d06e78b7cb-dirty #9 PREEMPT(undef) [ 0.164141] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 0.165439] RIP: 0010:kmem_cache_alloc_noprof (mm/slub.c:4237) [ 0.166186] Code: 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 49 89 fc 53 48 83 e4 f0 48 83 ec 20 8b 05 c9 b6 7e 01 <44> 8b 77 1c 65 4c 8b 2d b5 ea 20 02 4c 89 6c 24 18 41 89 f5 21 f0 [ 0.168811] RSP: 0000:ffffffffb2e03b30 EFLAGS: 00010086 [ 0.169545] RAX: 0000000001fff33f RBX: 0000000000000000 RCX: 0000000000000000 [ 0.170544] RDX: 0000000000002800 RSI: 0000000000002800 RDI: 0000000000000000 [ 0.171554] RBP: ffffffffb2e03b80 R08: 0000000000000004 R09: ffffffffb2e03c90 [ 0.172549] R10: ffffffffb2e03c90 R11: 0000000000000000 R12: 0000000000000000 [ 0.173544] R13: ffffffffb2e03c90 R14: ffffffffb2e03c90 R15: 0000000000000001 [ 0.174542] FS: 0000000000000000(0000) GS:ffff9d2808114000(0000) knlGS:0000000000000000 [ 0.175684] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.176486] CR2: 000000000000001c CR3: 000000007264c001 CR4: 00000000000200b0 [ 0.177483] Call Trace: [ 0.177828] <TASK> [ 0.178123] mas_alloc_nodes (lib/maple_tree.c:176 (discriminator 2) lib/maple_tree.c:1255 (discriminator 2)) [ 0.178692] mas_store_gfp (lib/maple_tree.c:5468) [ 0.179223] execmem_cache_add_locked (mm/execmem.c:207) [ 0.179870] execmem_alloc (mm/execmem.c:213 mm/execmem.c:313 mm/execmem.c:335 mm/execmem.c:475) [ 0.180397] ? ftrace_caller (arch/x86/kernel/ftrace_64.S:169) [ 0.180922] ? __pfx_ftrace_caller (arch/x86/kernel/ftrace_64.S:158) [ 0.181517] execmem_alloc_rw (mm/execmem.c:487) [ 0.182052] arch_ftrace_update_trampoline (arch/x86/kernel/ftrace.c:266 arch/x86/kernel/ftrace.c:344 arch/x86/kernel/ftrace.c:474) [ 0.182778] ? ftrace_caller_op_ptr (arch/x86/kernel/ftrace_64.S:182) [ 0.183388] ftrace_update_trampoline (kernel/trace/ftrace.c:7947) [ 0.184024] __register_ftrace_function (kernel/trace/ftrace.c:368) [ 0.184682] ftrace_startup (kernel/trace/ftrace.c:3048) [ 0.185205] ? __pfx_function_trace_call (kernel/trace/trace_functions.c:210) [ 0.185877] register_ftrace_function_nolock (kernel/trace/ftrace.c:8717) [ 0.186595] register_ftrace_function (kernel/trace/ftrace.c:8745) [ 0.187254] ? __pfx_function_trace_call (kernel/trace/trace_functions.c:210) [ 0.187924] function_trace_init (kernel/trace/trace_functions.c:170) [ 0.188499] tracing_set_tracer (kernel/trace/trace.c:5916 kernel/trace/trace.c:6349) [ 0.189088] register_tracer (kernel/trace/trace.c:2391) [ 0.189642] early_trace_init (kernel/trace/trace.c:11075 kernel/trace/trace.c:11149) [ 0.190204] start_kernel (init/main.c:970) [ 0.190732] x86_64_start_reservations (arch/x86/kernel/head64.c:307) [ 0.191381] x86_64_start_kernel (??:?) [ 0.191955] common_startup_64 (arch/x86/kernel/head_64.S:419) [ 0.192534] </TASK> [ 0.192839] Modules linked in: [ 0.193267] CR2: 000000000000001c [ 0.193730] ---[ end trace 0000000000000000 ]--- The crash happens because on x86 ftrace allocations from execmem require maple tree to be initialized. Move maple tree initialization that depends only on slab availability earlier in boot so that it will happen right after mm_core_init(). Link: https://lkml.kernel.org/r/20250824130759.1732736-1-rppt@kernel.org Fixes: 5d79c2be5081 ("x86/ftrace: enable EXECMEM_ROX_CACHE for ftrace allocations") Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reported-by: Steven Rostedt (Google) <rostedt@goodmis.org> Tested-by: Steven Rostedt (Google) <rostedt@goodmis.org> Closes: https://lore.kernel.org/all/20250820184743.0302a8b5@gandalf.local.home/ Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-08-03Merge tag 'mm-nonmm-stable-2025-08-03-12-47' of ↵Linus Torvalds1-1/+5
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: "Significant patch series in this pull request: - "squashfs: Remove page->mapping references" (Matthew Wilcox) gets us closer to being able to remove page->mapping - "relayfs: misc changes" (Jason Xing) does some maintenance and minor feature addition work in relayfs - "kdump: crashkernel reservation from CMA" (Jiri Bohac) switches us from static preallocation of the kdump crashkernel's working memory over to dynamic allocation. So the difficulty of a-priori estimation of the second kernel's needs is removed and the first kernel obtains extra memory - "generalize panic_print's dump function to be used by other kernel parts" (Feng Tang) implements some consolidation and rationalization of the various ways in which a failing kernel splats information at the operator * tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (80 commits) tools/getdelays: add backward compatibility for taskstats version kho: add test for kexec handover delaytop: enhance error logging and add PSI feature description samples: Kconfig: fix spelling mistake "instancess" -> "instances" fat: fix too many log in fat_chain_add() scripts/spelling.txt: add notifer||notifier to spelling.txt xen/xenbus: fix typo "notifer" net: mvneta: fix typo "notifer" drm/xe: fix typo "notifer" cxl: mce: fix typo "notifer" KVM: x86: fix typo "notifer" MAINTAINERS: add maintainers for delaytop ucount: use atomic_long_try_cmpxchg() in atomic_long_inc_below() ucount: fix atomic_long_inc_below() argument type kexec: enable CMA based contiguous allocation stackdepot: make max number of pools boot-time configurable lib/xxhash: remove unused functions init/Kconfig: restore CONFIG_BROKEN help text lib/raid6: update recov_rvv.c zero page usage docs: update docs after introducing delaytop ...
2025-07-19init/main.c: add warning when file specified in rdinit is inaccessibleLillian Berry1-1/+5
Avoid silently ignoring the initramfs when the file specified in rdinit is not usable. This prints an error that clearly explains the issue (file was not found, vs initramfs was not found). Link: https://lkml.kernel.org/r/20250707091411.1412681-1-lillian@star-ark.net Signed-off-by: Lillian Berry <lillian@star-ark.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-06-20x86/efi: Move runtime service initialization to arch/x86Alexander Shishkin1-5/+0
The EFI call in start_kernel() is guarded by #ifdef CONFIG_X86. Move the thing to the arch_cpu_finalize_init() path on x86 and get rid of the #ifdef in start_kernel(). No functional change intended. Suggested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Sohil Mehta <sohil.mehta@intel.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/all/20250620135325.3300848-5-kirill.shutemov%40linux.intel.com
2025-06-11init: fix build warnings about export.hHuacai Chen1-0/+1
After commit a934a57a42f64a4 ("scripts/misc-check: check missing #include <linux/export.h> when W=1") and 7d95680d64ac8e836c ("scripts/misc-check: check unnecessary #include <linux/export.h> when W=1"), we get some build warnings with W=1: init/main.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing init/initramfs.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing So fix these build warnings for the init code. Link: https://lkml.kernel.org/r/20250608141235.155206-1-chenhuacai@loongson.cn Fixes: a934a57a42f6 ("scripts/misc-check: check missing #include <linux/export.h> when W=1") Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Reviewed-by: Masahiro Yamada <masahiroy@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31Merge tag 'mm-nonmm-stable-2025-05-31-15-28' of ↵Linus Torvalds1-2/+16
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: - "hung_task: extend blocking task stacktrace dump to semaphore" from Lance Yang enhances the hung task detector. The detector presently dumps the blocking tasks's stack when it is blocked on a mutex. Lance's series extends this to semaphores - "nilfs2: improve sanity checks in dirty state propagation" from Wentao Liang addresses a couple of minor flaws in nilfs2 - "scripts/gdb: Fixes related to lx_per_cpu()" from Illia Ostapyshyn fixes a couple of issues in the gdb scripts - "Support kdump with LUKS encryption by reusing LUKS volume keys" from Coiby Xu addresses a usability problem with kdump. When the dump device is LUKS-encrypted, the kdump kernel may not have the keys to the encrypted filesystem. A full writeup of this is in the series [0/N] cover letter - "sysfs: add counters for lockups and stalls" from Max Kellermann adds /sys/kernel/hardlockup_count and /sys/kernel/hardlockup_count and /sys/kernel/rcu_stall_count - "fork: Page operation cleanups in the fork code" from Pasha Tatashin implements a number of code cleanups in fork.c - "scripts/gdb/symbols: determine KASLR offset on s390 during early boot" from Ilya Leoshkevich fixes some s390 issues in the gdb scripts * tag 'mm-nonmm-stable-2025-05-31-15-28' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (67 commits) llist: make llist_add_batch() a static inline delayacct: remove redundant code and adjust indentation squashfs: add optional full compressed block caching crash_dump, nvme: select CONFIGFS_FS as built-in scripts/gdb/symbols: determine KASLR offset on s390 during early boot scripts/gdb/symbols: factor out pagination_off() scripts/gdb/symbols: factor out get_vmlinux() kernel/panic.c: format kernel-doc comments mailmap: update and consolidate Casey Connolly's name and email nilfs2: remove wbc->for_reclaim handling fork: define a local GFP_VMAP_STACK fork: check charging success before zeroing stack fork: clean-up naming of vm_stack/vm_struct variables in vmap stacks code fork: clean-up ifdef logic around stack allocation kernel/rcu/tree_stall: add /sys/kernel/rcu_stall_count kernel/watchdog: add /sys/kernel/{hard,soft}lockup_count x86/crash: make the page that stores the dm crypt keys inaccessible x86/crash: pass dm crypt keys to kdump kernel Revert "x86/mm: Remove unused __set_memory_prot()" crash_dump: retrieve dm crypt keys in kdump kernel ...
2025-05-31Merge tag 'mm-stable-2025-05-31-14-50' of ↵Linus Torvalds1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - "Add folio_mk_pte()" from Matthew Wilcox simplifies the act of creating a pte which addresses the first page in a folio and reduces the amount of plumbing which architecture must implement to provide this. - "Misc folio patches for 6.16" from Matthew Wilcox is a shower of largely unrelated folio infrastructure changes which clean things up and better prepare us for future work. - "memory,x86,acpi: hotplug memory alignment advisement" from Gregory Price adds early-init code to prevent x86 from leaving physical memory unused when physical address regions are not aligned to memory block size. - "mm/compaction: allow more aggressive proactive compaction" from Michal Clapinski provides some tuning of the (sadly, hard-coded (more sadly, not auto-tuned)) thresholds for our invokation of proactive compaction. In a simple test case, the reduction of a guest VM's memory consumption was dramatic. - "Minor cleanups and improvements to swap freeing code" from Kemeng Shi provides some code cleaups and a small efficiency improvement to this part of our swap handling code. - "ptrace: introduce PTRACE_SET_SYSCALL_INFO API" from Dmitry Levin adds the ability for a ptracer to modify syscalls arguments. At this time we can alter only "system call information that are used by strace system call tampering, namely, syscall number, syscall arguments, and syscall return value. This series should have been incorporated into mm.git's "non-MM" branch, but I goofed. - "fs/proc: extend the PAGEMAP_SCAN ioctl to report guard regions" from Andrei Vagin extends the info returned by the PAGEMAP_SCAN ioctl against /proc/pid/pagemap. This permits CRIU to more efficiently get at the info about guard regions. - "Fix parameter passed to page_mapcount_is_type()" from Gavin Shan implements that fix. No runtime effect is expected because validate_page_before_insert() happens to fix up this error. - "kernel/events/uprobes: uprobe_write_opcode() rewrite" from David Hildenbrand basically brings uprobe text poking into the current decade. Remove a bunch of hand-rolled implementation in favor of using more current facilities. - "mm/ptdump: Drop assumption that pxd_val() is u64" from Anshuman Khandual provides enhancements and generalizations to the pte dumping code. This might be needed when 128-bit Page Table Descriptors are enabled for ARM. - "Always call constructor for kernel page tables" from Kevin Brodsky ensures that the ctor/dtor is always called for kernel pgtables, as it already is for user pgtables. This permits the addition of more functionality such as "insert hooks to protect page tables". This change does result in various architectures performing unnecesary work, but this is fixed up where it is anticipated to occur. - "Rust support for mm_struct, vm_area_struct, and mmap" from Alice Ryhl adds plumbing to permit Rust access to core MM structures. - "fix incorrectly disallowed anonymous VMA merges" from Lorenzo Stoakes takes advantage of some VMA merging opportunities which we've been missing for 15 years. - "mm/madvise: batch tlb flushes for MADV_DONTNEED and MADV_FREE" from SeongJae Park optimizes process_madvise()'s TLB flushing. Instead of flushing each address range in the provided iovec, we batch the flushing across all the iovec entries. The syscall's cost was approximately halved with a microbenchmark which was designed to load this particular operation. - "Track node vacancy to reduce worst case allocation counts" from Sidhartha Kumar makes the maple tree smarter about its node preallocation. stress-ng mmap performance increased by single-digit percentages and the amount of unnecessarily preallocated memory was dramaticelly reduced. - "mm/gup: Minor fix, cleanup and improvements" from Baoquan He removes a few unnecessary things which Baoquan noted when reading the code. - ""Enhance sysfs handling for memory hotplug in weighted interleave" from Rakie Kim "enhances the weighted interleave policy in the memory management subsystem by improving sysfs handling, fixing memory leaks, and introducing dynamic sysfs updates for memory hotplug support". Fixes things on error paths which we are unlikely to hit. - "mm/damon: auto-tune DAMOS for NUMA setups including tiered memory" from SeongJae Park introduces new DAMOS quota goal metrics which eliminate the manual tuning which is required when utilizing DAMON for memory tiering. - "mm/vmalloc.c: code cleanup and improvements" from Baoquan He provides cleanups and small efficiency improvements which Baoquan found via code inspection. - "vmscan: enforce mems_effective during demotion" from Gregory Price changes reclaim to respect cpuset.mems_effective during demotion when possible. because presently, reclaim explicitly ignores cpuset.mems_effective when demoting, which may cause the cpuset settings to violated. This is useful for isolating workloads on a multi-tenant system from certain classes of memory more consistently. - "Clean up split_huge_pmd_locked() and remove unnecessary folio pointers" from Gavin Guo provides minor cleanups and efficiency gains in in the huge page splitting and migrating code. - "Use kmem_cache for memcg alloc" from Huan Yang creates a slab cache for `struct mem_cgroup', yielding improved memory utilization. - "add max arg to swappiness in memory.reclaim and lru_gen" from Zhongkun He adds a new "max" argument to the "swappiness=" argument for memory.reclaim MGLRU's lru_gen. This directs proactive reclaim to reclaim from only anon folios rather than file-backed folios. - "kexec: introduce Kexec HandOver (KHO)" from Mike Rapoport is the first step on the path to permitting the kernel to maintain existing VMs while replacing the host kernel via file-based kexec. At this time only memblock's reserve_mem is preserved. - "mm: Introduce for_each_valid_pfn()" from David Woodhouse provides and uses a smarter way of looping over a pfn range. By skipping ranges of invalid pfns. - "sched/numa: Skip VMA scanning on memory pinned to one NUMA node via cpuset.mems" from Libo Chen removes a lot of pointless VMA scanning when a task is pinned a single NUMA mode. Dramatic performance benefits were seen in some real world cases. - "JFS: Implement migrate_folio for jfs_metapage_aops" from Shivank Garg addresses a warning which occurs during memory compaction when using JFS. - "move all VMA allocation, freeing and duplication logic to mm" from Lorenzo Stoakes moves some VMA code from kernel/fork.c into the more appropriate mm/vma.c. - "mm, swap: clean up swap cache mapping helper" from Kairui Song provides code consolidation and cleanups related to the folio_index() function. - "mm/gup: Cleanup memfd_pin_folios()" from Vishal Moola does that. - "memcg: Fix test_memcg_min/low test failures" from Waiman Long addresses some bogus failures which are being reported by the test_memcontrol selftest. - "eliminate mmap() retry merge, add .mmap_prepare hook" from Lorenzo Stoakes commences the deprecation of file_operations.mmap() in favor of the new file_operations.mmap_prepare(). The latter is more restrictive and prevents drivers from messing with things in ways which, amongst other problems, may defeat VMA merging. - "memcg: decouple memcg and objcg stocks"" from Shakeel Butt decouples the per-cpu memcg charge cache from the objcg's one. This is a step along the way to making memcg and objcg charging NMI-safe, which is a BPF requirement. - "mm/damon: minor fixups and improvements for code, tests, and documents" from SeongJae Park is yet another batch of miscellaneous DAMON changes. Fix and improve minor problems in code, tests and documents. - "memcg: make memcg stats irq safe" from Shakeel Butt converts memcg stats to be irq safe. Another step along the way to making memcg charging and stats updates NMI-safe, a BPF requirement. - "Let unmap_hugepage_range() and several related functions take folio instead of page" from Fan Ni provides folio conversions in the hugetlb code. * tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (285 commits) mm: pcp: increase pcp->free_count threshold to trigger free_high mm/hugetlb: convert use of struct page to folio in __unmap_hugepage_range() mm/hugetlb: refactor __unmap_hugepage_range() to take folio instead of page mm/hugetlb: refactor unmap_hugepage_range() to take folio instead of page mm/hugetlb: pass folio instead of page to unmap_ref_private() memcg: objcg stock trylock without irq disabling memcg: no stock lock for cpu hot-unplug memcg: make __mod_memcg_lruvec_state re-entrant safe against irqs memcg: make count_memcg_events re-entrant safe against irqs memcg: make mod_memcg_state re-entrant safe against irqs memcg: move preempt disable to callers of memcg_rstat_updated memcg: memcg_rstat_updated re-entrant safe against irqs mm: khugepaged: decouple SHMEM and file folios' collapse selftests/eventfd: correct test name and improve messages alloc_tag: check mem_profiling_support in alloc_tag_init Docs/damon: update titles and brief introductions to explain DAMOS selftests/damon/_damon_sysfs: read tried regions directories in order mm/damon/tests/core-kunit: add a test for damos_set_filters_default_reject() mm/damon/paddr: remove unused variable, folio_list, in damon_pa_stat() mm/damon/sysfs-schemes: fix wrong comment on damons_sysfs_quota_goal_metric_strs ...
2025-05-12mm/memcg: move mem_cgroup_init() ahead of cgroup_init()Huan Yang1-0/+2
Patch series "Use kmem_cache for memcg alloc", v3. (willy tldr: "you've gone from allocating 8 objects per 32KiB to allocating 13 objects per 32KiB, a 62% improvement in memory consumption" [1]) The mem_cgroup_alloc function creates mem_cgroup struct and it's associated structures including mem_cgroup_per_node. Through detailed analysis on our test machine (Arm64, 16GB RAM, 6.6 kernel, 1 NUMA node, memcgv2 with nokmem,nosocket,cgroup_disable=pressure), we can observe the memory allocation for these structures using the following shell commands: # Enable tracing echo 1 > /sys/kernel/tracing/events/kmem/kmalloc/enable echo 1 > /sys/kernel/tracing/tracing_on cat /sys/kernel/tracing/trace_pipe | grep kmalloc | grep mem_cgroup # Trigger allocation if cgroup subtree do not enable memcg echo +memory > /sys/fs/cgroup/cgroup.subtree_control Ftrace Output: # mem_cgroup struct allocation sh-6312 [000] ..... 58015.698365: kmalloc: call_site=mem_cgroup_css_alloc+0xd8/0x5b4 ptr=000000003e4c3799 bytes_req=2312 bytes_alloc=4096 gfp_flags=GFP_KERNEL|__GFP_ZERO node=-1 accounted=false # mem_cgroup_per_node allocation sh-6312 [000] ..... 58015.698389: kmalloc: call_site=mem_cgroup_css_alloc+0x1d8/0x5b4 ptr=00000000d798700c bytes_req=2896 bytes_alloc=4096 gfp_flags=GFP_KERNEL|__GFP_ZERO node=0 accounted=false Key Observations: 1. Both structures use kmalloc with requested sizes between 2KB-4KB 2. Allocation alignment forces 4KB slab usage due to pre-defined sizes (64B, 128B,..., 2KB, 4KB, 8KB) 3. Memory waste per memcg instance: Base struct: 4096 - 2312 = 1784 bytes Per-node struct: 4096 - 2896 = 1200 bytes Total waste: 2984 bytes (1-node system) NUMA scaling: (1200 + 8) * nr_node_ids bytes So, it's a little waste. This patchset introduces dedicated kmem_cache: Patch2 - mem_cgroup kmem_cache - memcg_cachep Patch3 - mem_cgroup_per_node kmem_cache - memcg_pn_cachep The benefits of this change can be observed with the following tracing commands: # Enable tracing echo 1 > /sys/kernel/tracing/events/kmem/kmem_cache_alloc/enable echo 1 > /sys/kernel/tracing/tracing_on cat /sys/kernel/tracing/trace_pipe | grep kmem_cache_alloc | grep mem_cgroup # In another terminal: echo +memory > /sys/fs/cgroup/cgroup.subtree_control The output might now look like this: # mem_cgroup struct allocation sh-9827 [000] ..... 289.513598: kmem_cache_alloc: call_site=mem_cgroup_css_alloc+0xbc/0x5d4 ptr=00000000695c1806 bytes_req=2312 bytes_alloc=2368 gfp_flags=GFP_KERNEL|__GFP_ZERO node=-1 accounted=false # mem_cgroup_per_node allocation sh-9827 [000] ..... 289.513602: kmem_cache_alloc: call_site=mem_cgroup_css_alloc+0x1b8/0x5d4 ptr=000000002989e63a bytes_req=2896 bytes_alloc=2944 gfp_flags=GFP_KERNEL|__GFP_ZERO node=0 accounted=false This indicates that the `mem_cgroup` struct now requests 2312 bytes and is allocated 2368 bytes, while `mem_cgroup_per_node` requests 2896 bytes and is allocated 2944 bytes. The slight increase in allocated size is due to `SLAB_HWCACHE_ALIGN` in the `kmem_cache`. Without `SLAB_HWCACHE_ALIGN`, the allocation might appear as: # mem_cgroup struct allocation sh-9269 [003] ..... 80.396366: kmem_cache_alloc: call_site=mem_cgroup_css_alloc+0xbc/0x5d4 ptr=000000005b12b475 bytes_req=2312 bytes_alloc=2312 gfp_flags=GFP_KERNEL|__GFP_ZERO node=-1 accounted=false # mem_cgroup_per_node allocation sh-9269 [003] ..... 80.396411: kmem_cache_alloc: call_site=mem_cgroup_css_alloc+0x1b8/0x5d4 ptr=00000000f347adc6 bytes_req=2896 bytes_alloc=2896 gfp_flags=GFP_KERNEL|__GFP_ZERO node=0 accounted=false While the `bytes_alloc` now matches the `bytes_req`, this patchset defaults to using `SLAB_HWCACHE_ALIGN` as it is generally considered more beneficial for performance. Please let me know if there are any issues or if I've misunderstood anything. This patchset also move mem_cgroup_init ahead of cgroup_init() due to cgroup_init() will allocate root_mem_cgroup, but each initcall invoke after cgroup_init, so if each kmem_cache do not prepare, we need testing NULL before use it. This patch (of 3): When cgroup_init() creates root_mem_cgroup through css_alloc callback, some critical resources might not be fully initialized, forcing later operations to perform conditional checks for resource availability. This patch move mem_cgroup_init() to address the init order, it invoke before cgroup_init, so, compare to subsys_initcall, it can use to prepare some key resources before root_mem_cgroup alloc. Link: https://lkml.kernel.org/r/aAsRCj-niMMTtmK8@casper.infradead.org [1] Link: https://lkml.kernel.org/r/20250425031935.76411-1-link@vivo.com Link: https://lkml.kernel.org/r/20250425031935.76411-2-link@vivo.com Signed-off-by: Huan Yang <link@vivo.com> Suggested-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Francesco Valla <francesco@valla.it> Cc: guoweikang <guoweikang.kernel@gmail.com> Cc: Huang Shijie <shijie@os.amperecomputing.com> Cc: KP Singh <kpsingh@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Raul E Rangel <rrangel@chromium.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-11init/main.c: log initcall level when initcall_debug is usedFrancesco Valla1-2/+16
When initcall_debug is specified on the command line, the start and return point for each initcall is printed. However, no information on the initcall level is reported. Add to the initcall_debug infrastructure an additional print that informs when a new initcall level is entered. This is particularly useful when debugging dependency chains and/or working on boot time reduction. Link: https://lkml.kernel.org/r/20250316205014.2830071-2-francesco@valla.it Signed-off-by: Francesco Valla <francesco@valla.it> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tim Bird <tim.bird@sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-08timers: Rename init_timers() as timers_init()Ingo Molnar1-1/+1
Move this API to the canonical timers_*() namespace. Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250507175338.672442-8-mingo@kernel.org
2025-03-04rcu-tasks: Move RCU Tasks self-tests to core_initcall()Paul E. McKenney1-1/+0
The timer and hrtimer softirq processing has moved to dedicated threads for kernels built with CONFIG_IRQ_FORCED_THREADING=y. This results in timers not expiring until later in early boot, which in turn causes the RCU Tasks self-tests to hang in kernels built with CONFIG_PROVE_RCU=y, which further causes the entire kernel to hang. One fix would be to make timers work during this time, but there are no known users of RCU Tasks grace periods during that time, so no justification for the added complexity. Not yet, anyway. This commit therefore moves the call to rcu_init_tasks_generic() from kernel_init_freeable() to a core_initcall(). This works because the timer and hrtimer kthreads are created at early_initcall() time. Fixes: 49a17639508c3 ("softirq: Use a dedicated thread for timer wakeups on PREEMPT_RT.") Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: <linux-trace-kernel@vger.kernel.org> Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
2025-01-26Merge tag 'mm-stable-2025-01-26-14-59' of ↵Linus Torvalds1-14/+4
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "The various patchsets are summarized below. Plus of course many indivudual patches which are described in their changelogs. - "Allocate and free frozen pages" from Matthew Wilcox reorganizes the page allocator so we end up with the ability to allocate and free zero-refcount pages. So that callers (ie, slab) can avoid a refcount inc & dec - "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to use large folios other than PMD-sized ones - "Fix mm/rodata_test" from Petr Tesarik performs some maintenance and fixes for this small built-in kernel selftest - "mas_anode_descend() related cleanup" from Wei Yang tidies up part of the mapletree code - "mm: fix format issues and param types" from Keren Sun implements a few minor code cleanups - "simplify split calculation" from Wei Yang provides a few fixes and a test for the mapletree code - "mm/vma: make more mmap logic userland testable" from Lorenzo Stoakes continues the work of moving vma-related code into the (relatively) new mm/vma.c - "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David Hildenbrand cleans up and rationalizes handling of gfp flags in the page allocator - "readahead: Reintroduce fix for improper RA window sizing" from Jan Kara is a second attempt at fixing a readahead window sizing issue. It should reduce the amount of unnecessary reading - "synchronously scan and reclaim empty user PTE pages" from Qi Zheng addresses an issue where "huge" amounts of pte pagetables are accumulated: https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/ Qi's series addresses this windup by synchronously freeing PTE memory within the context of madvise(MADV_DONTNEED) - "selftest/mm: Remove warnings found by adding compiler flags" from Muhammad Usama Anjum fixes some build warnings in the selftests code when optional compiler warnings are enabled - "mm: don't use __GFP_HARDWALL when migrating remote pages" from David Hildenbrand tightens the allocator's observance of __GFP_HARDWALL - "pkeys kselftests improvements" from Kevin Brodsky implements various fixes and cleanups in the MM selftests code, mainly pertaining to the pkeys tests - "mm/damon: add sample modules" from SeongJae Park enhances DAMON to estimate application working set size - "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn provides some cleanups to memcg's hugetlb charging logic - "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song removes the global swap cgroup lock. A speedup of 10% for a tmpfs-based kernel build was demonstrated - "zram: split page type read/write handling" from Sergey Senozhatsky has several fixes and cleaups for zram in the area of zram_write_page(). A watchdog softlockup warning was eliminated - "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin Brodsky cleans up the pagetable destructor implementations. A rare use-after-free race is fixed - "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes simplifies and cleans up the debugging code in the VMA merging logic - "Account page tables at all levels" from Kevin Brodsky cleans up and regularizes the pagetable ctor/dtor handling. This results in improvements in accounting accuracy - "mm/damon: replace most damon_callback usages in sysfs with new core functions" from SeongJae Park cleans up and generalizes DAMON's sysfs file interface logic - "mm/damon: enable page level properties based monitoring" from SeongJae Park increases the amount of information which is presented in response to DAMOS actions - "mm/damon: remove DAMON debugfs interface" from SeongJae Park removes DAMON's long-deprecated debugfs interfaces. Thus the migration to sysfs is completed - "mm/hugetlb: Refactor hugetlb allocation resv accounting" from Peter Xu cleans up and generalizes the hugetlb reservation accounting - "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino removes a never-used feature of the alloc_pages_bulk() interface - "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park extends DAMOS filters to support not only exclusion (rejecting), but also inclusion (allowing) behavior - "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi introduces a new memory descriptor for zswap.zpool that currently overlaps with struct page for now. This is part of the effort to reduce the size of struct page and to enable dynamic allocation of memory descriptors - "mm, swap: rework of swap allocator locks" from Kairui Song redoes and simplifies the swap allocator locking. A speedup of 400% was demonstrated for one workload. As was a 35% reduction for kernel build time with swap-on-zram - "mm: update mips to use do_mmap(), make mmap_region() internal" from Lorenzo Stoakes reworks MIPS's use of mmap_region() so that mmap_region() can be made MM-internal - "mm/mglru: performance optimizations" from Yu Zhao fixes a few MGLRU regressions and otherwise improves MGLRU performance - "Docs/mm/damon: add tuning guide and misc updates" from SeongJae Park updates DAMON documentation - "Cleanup for memfd_create()" from Isaac Manjarres does that thing - "mm: hugetlb+THP folio and migration cleanups" from David Hildenbrand provides various cleanups in the areas of hugetlb folios, THP folios and migration - "Uncached buffered IO" from Jens Axboe implements the new RWF_DONTCACHE flag which provides synchronous dropbehind for pagecache reading and writing. To permite userspace to address issues with massive buildup of useless pagecache when reading/writing fast devices - "selftests/mm: virtual_address_range: Reduce memory" from Thomas Weißschuh fixes and optimizes some of the MM selftests" * tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits) mm/compaction: fix UBSAN shift-out-of-bounds warning s390/mm: add missing ctor/dtor on page table upgrade kasan: sw_tags: use str_on_off() helper in kasan_init_sw_tags() tools: add VM_WARN_ON_VMG definition mm/damon/core: use str_high_low() helper in damos_wmark_wait_us() seqlock: add missing parameter documentation for raw_seqcount_try_begin() mm/page-writeback: consolidate wb_thresh bumping logic into __wb_calc_thresh mm/page_alloc: remove the incorrect and misleading comment zram: remove zcomp_stream_put() from write_incompressible_page() mm: separate move/undo parts from migrate_pages_batch() mm/kfence: use str_write_read() helper in get_access_type() selftests/mm/mkdirty: fix memory leak in test_uffdio_copy() kasan: hw_tags: Use str_on_off() helper in kasan_init_hw_tags() selftests/mm: virtual_address_range: avoid reading from VM_IO mappings selftests/mm: vm_util: split up /proc/self/smaps parsing selftests/mm: virtual_address_range: unmap chunks after validation selftests/mm: virtual_address_range: mmap() without PROT_WRITE selftests/memfd/memfd_test: fix possible NULL pointer dereference mm: add FGP_DONTCACHE folio creation flag mm: call filemap_fdatawrite_range_kick() after IOCB_DONTCACHE issue ...
2025-01-25mm/memblock: add memblock_alloc_or_panic interfaceGuo Weikang1-14/+4
Before SLUB initialization, various subsystems used memblock_alloc to allocate memory. In most cases, when memory allocation fails, an immediate panic is required. To simplify this behavior and reduce repetitive checks, introduce `memblock_alloc_or_panic`. This function ensures that memory allocation failures result in a panic automatically, improving code readability and consistency across subsystems that require this behavior. [guoweikang.kernel@gmail.com: arch/s390: save_area_alloc default failure behavior changed to panic] Link: https://lkml.kernel.org/r/20250109033136.2845676-1-guoweikang.kernel@gmail.com Link: https://lore.kernel.org/lkml/Z2fknmnNtiZbCc7x@kernel.org/ Link: https://lkml.kernel.org/r/20250102072528.650926-1-guoweikang.kernel@gmail.com Signed-off-by: Guo Weikang <guoweikang.kernel@gmail.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> [s390] Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-11rcu/kvfree: Initialize kvfree_rcu() separatelyUladzislau Rezki (Sony)1