Pull NOHZ updates from Thomas Gleixner:
- Fix a long standing TOCTOU in get_cpu_sleep_time_us()
- Make the CPU offline NOHZ handling more robust by disabling NOHZ on
the outgoing CPU early instead of creating unneeded state which needs
to be undone.
- Unify idle CPU time accounting instead of having two different
accounting mechanisms. These two different mechanisms are not really
independent, but the different properties can in the worst case cause
that gloabl idle time can be observed going backwards.
- Consolidate the idle/iowait time retrieval interfaces instead of
converting back and forth between them.
- Make idle interrupt time accounting more robust. The original code
assumes that interrupt time accouting is enabled and therefore stops
elapsing idle time while an interrupt is handled in NOHZ dyntick
state. That assumption is not correct as interrupt time accounting
can be disabled at compile and runtime.
- Fix an accounting error between dyntick idle time and dyntick idle
steal time. The stolen time is not accounted and therefore idle time
becomes inaccurate. The stolen time is now accounted after the fact
as there is no way to predict the steal time upfront.
* tag 'timers-nohz-2026-06-13' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip:
sched/cputime: Handle dyntick-idle steal time correctly
sched/cputime: Handle idle irqtime gracefully
sched/cputime: Provide get_cpu_[idle|iowait]_time_us() off-case
tick/sched: Consolidate idle time fetching APIs
tick/sched: Account tickless idle cputime only when tick is stopped
tick/sched: Remove unused fields
tick/sched: Move dyntick-idle cputime accounting to cputime code
tick/sched: Remove nohz disabled special case in cputime fetch
tick/sched: Unify idle cputime accounting
s390/time: Prepare to stop elapsing in dynticks-idle
powerpc/time: Prepare to stop elapsing in dynticks-idle
sched/cputime: Correctly support generic vtime idle time
sched/cputime: Remove superfluous and error prone kcpustat_field() parameter
sched/idle: Handle offlining first in idle loop
tick/sched: Fix TOCTOU in nohz idle time fetch
Pull interrupt core updates from Thomas Gleixner:
- Rework of /proc/interrupt handling:
/proc/interrupts was subject to micro optimizations for a long time,
but most of the low hanging fruit was left on the table. This rework
addresses the major time consuming issues:
- Printing a long series of zeros one by one via a format string
instead of counting subsequent zeros and emitting a string
constant.
- Simplify and cache the conditions whether interrupts should be
printed
- Use a proper iteration over the interrupt descriptor xarray
instead of walking and testing one by one.
- Provide helper functions for the architecture code to emit the
architecture specific counters
- Convert the counter structure in x86 to an array, which
simplifies the output and add mechanisms to suppress unused
architecture interrupts, which just occupy space for nothing.
Adopt the new core mechanisms.
This adjusts the gdb scripts related to interrupt counter statistics
to work with the new mechanisms.
- Prevent a string overflow in the /proc/irq/$N/ directory name
creation code.
* tag 'irq-core-2026-06-13' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip:
x86/irq: Add missing 's' back to thermal event printout
genirq/proc: Speed up /proc/interrupts iteration
genirq/proc: Runtime size the chip name
genirq: Expose irq_find_desc_at_or_after() in core code
genirq: Add rcuref count to struct irq_desc
genirq/proc: Increase default interrupt number precision to four
genirq: Calculate precision only when required
genirq: Cache the condition for /proc/interrupts exposure
genirq/manage: Make NMI cleanup RT safe
genirq: Expose nr_irqs in core code
scripts/gdb: Update x86 interrupts to the array based storage
x86/irq: Move IOAPIC misrouted and PIC/APIC error counts into irq_stats
x86/irq: Suppress unlikely interrupt stats by default
x86/irq: Make irqstats array based
genirq/proc: Utilize irq_desc::tot_count to avoid evaluation
genirq/proc: Avoid formatting zero counts in /proc/interrupts
x86/irq: Optimize interrupts decimals printing
genirq/proc: Size interrupt directory names for 10-digit interrupt numbers
The chip name column in the /proc/interrupt output is 8 characters and
right aligned, which causes visual clutter due to the fixed length and the
alignment. Many interrupt chips, e.g. PCI/MSI[X] have way longer names.
Update the length when a chip is assigned to an interrupt and utilize this
information for the output. Align it left so all chip names start at the
begin of the column.
Update the GDB script as well and disentangle the header maze so it
actually works with all .config combinations.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Dmitry Ilvokhin <d@ilvokhin.com>
Link: https://patch.msgid.link/20260517194932.085786035@kernel.org
Quite some architectures have four character wide acronyms for architecture
specific interrupts like IPI, NMI, etc.
The default precision of printing the Linux device interrupt numbers is
three, which causes quite some code to play games with adding or omitting
space after the acronym and the colon in order to keep the per CPU numbers
properly aligned.
Increase the default number precision to four in the core code and get rid
of the space games all over the place. At the same time align all
architecture specific descriptor texts left so that they show up in the
same column as the interrupt chip names, which makes the output more
uniform accross architectures. Fix up the GDB script to this new scheme as
well.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260517194931.839482411@kernel.org
x86 changed the interrupt statistics from a struct with individual members
to an counter array. It also provides a corresponding info array with the
strings for prefix and description and an indicator to skip the entry.
Update the already out of sync GDB script to use the counter and the info
array, which keeps the GDB script in sync automatically.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://patch.msgid.link/20260517194931.442613033@kernel.org
Pull non-MM updates from Andrew Morton:
- "pid: make sub-init creation retryable" (Oleg Nesterov)
Make creation of init in a new namespace more robust by clearing away
some historical cruft which is no longer needed. Also some
documentation fixups
- "selftests/fchmodat2: Error handling and general" (Mark Brown)
Fix and a cleanup for the fchmodat2() syscall selftest
- "lib: polynomial: Move to math/ and clean up" (Andy Shevchenko)
- "hung_task: Provide runtime reset interface for hung task detector"
(Aaron Tomlin)
Give administrators the ability to zero out
/proc/sys/kernel/hung_task_detect_count
- "tools/getdelays: use the static UAPI headers from
tools/include/uapi" (Thomas Weißschuh)
Teach getdelays to use the in-kernel UAPI headers rather than the
system-provided ones
- "watchdog/hardlockup: Improvements to hardlockup" (Mayank Rungta)
Several cleanups and fixups to the hardlockup detector code and its
documentation
- "lib/bch: fix undefined behavior from signed left-shifts" (Josh Law)
A couple of small/theoretical fixes in the bch code
- "ocfs2/dlm: fix two bugs in dlm_match_regions()" (Junrui Luo)
- "cleanup the RAID5 XOR library" (Christoph Hellwig)
A quite far-reaching cleanup to this code. I can't do better than to
quote Christoph:
"The XOR library used for the RAID5 parity is a bit of a mess right
now. The main file sits in crypto/ despite not being cryptography
and not using the crypto API, with the generic implementations
sitting in include/asm-generic and the arch implementations
sitting in an asm/ header in theory. The latter doesn't work for
many cases, so architectures often build the code directly into
the core kernel, or create another module for the architecture
code.
Change this to a single module in lib/ that also contains the
architecture optimizations, similar to the library work Eric
Biggers has done for the CRC and crypto libraries later. After
that it changes to better calling conventions that allow for
smarter architecture implementations (although none is contained
here yet), and uses static_call to avoid indirection function call
overhead"
- "lib/list_sort: Clean up list_sort() scheduling workarounds"
(Kuan-Wei Chiu)
Clean up this library code by removing a hacky thing which was added
for UBIFS, which UBIFS doesn't actually need
- "Fix bugs in extract_iter_to_sg()" (Christian Ehrhardt)
Fix a few bugs in the scatterlist code, add in-kernel tests for the
now-fixed bugs and fix a leak in the test itself
- "kdump: Enable LUKS-encrypted dump target support in ARM64 and
PowerPC" (Coiby Xu)
Enable support of the LUKS-encrypted device dump target on arm64 and
powerpc
- "ocfs2: consolidate extent list validation into block read callbacks"
(Joseph Qi)
Cleanup, simplify, and make more robust ocfs2's validation of extent
list fields (Kernel test robot loves mounting corrupted fs images!)
* tag 'mm-nonmm-stable-2026-04-15-04-20' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (127 commits)
ocfs2: validate group add input before caching
ocfs2: validate bg_bits during freefrag scan
ocfs2: fix listxattr handling when the buffer is full
doc: watchdog: fix typos etc
update Sean's email address
ocfs2: use get_random_u32() where appropriate
ocfs2: split transactions in dio completion to avoid credit exhaustion
ocfs2: remove redundant l_next_free_rec check in __ocfs2_find_path()
ocfs2: validate extent block list fields during block read
ocfs2: remove empty extent list check in ocfs2_dx_dir_lookup_rec()
ocfs2: validate dx_root extent list fields during block read
ocfs2: fix use-after-free in ocfs2_fault() when VM_FAULT_RETRY
ocfs2: handle invalid dinode in ocfs2_group_extend
.get_maintainer.ignore: add Askar
ocfs2: validate bg_list extent bounds in discontig groups
checkpatch: exclude forward declarations of const structs
tools/accounting: handle truncated taskstats netlink messages
taskstats: set version in TGID exit notifications
ocfs2/heartbeat: fix slot mapping rollback leaks on error paths
arm64,ppc64le/kdump: pass dm-crypt keys to kdump kernel
...
One can debug BPF programs with QEMU gdbstub by setting a breakpoint on
bpf_prog_kallsyms_add(), waiting for a hit with a matching aux.name, and
then setting a breakpoint on bpf_func. This is tedious, error-prone, and
also lacks line numbers.
Automate this in a way similar to the existing support for modules in
lx-symbols.
Enumerate and monitor changes to both BPF kallsyms and JITed progs. For
each ksym, generate and compile a synthetic .s file containing the name,
code, and size. In addition, if this ksym is also a prog, and not a
trampoline, add line number information.
Ensure that this is a no-op if the kernel is built without BPF support or
if "as" is missing. In theory the "as" dependency may be dropped by
generating the synthetic .o file manually, but this is too much complexity
for too little benefit.
Now one can debug BPF progs out of the box like this:
(gdb) lx-symbols -bpf
(gdb) b bpf_prog_4e612a6a881a086b_arena_list_add
Breakpoint 2 (bpf_prog_4e612a6a881a086b_arena_list_add) pending.
# ./test_progs -t arena_list
Thread 4 hit Breakpoint 2, bpf_prog_4e612a6a881a086b_arena_list_add ()
at linux/tools/testing/selftests/bpf/progs/arena_list.c:51
51 list_head = &global_head;
(gdb) n
bpf_prog_4e612a6a881a086b_arena_list_add () at linux/tools/testing/selftests/bpf/progs/arena_list.c:53
53 for (i = zero; i < cnt && can_loop; i++) {
This also works for subprogs.
Link: https://lkml.kernel.org/r/20251106124600.86736-3-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkman <daniel@iogearbox.net>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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
...
Pull s390 updates from Alexander Gordeev:
- Standardize on the __ASSEMBLER__ macro that is provided by GCC and
Clang compilers and replace __ASSEMBLY__ with __ASSEMBLER__ in both
uapi and non-uapi headers
- Explicitly include <linux/export.h> in architecture and driver files
which contain an EXPORT_SYMBOL() and remove the include from the
files which do not contain the EXPORT_SYMBOL()
- Use the full title of "z/Architecture Principles of Operation" manual
and the name of a section where facility bits are listed
- Use -D__DISABLE_EXPORTS for files in arch/s390/boot to avoid
unnecessary slowing down of the build and confusing external kABI
tools that process symtypes data
- Print additional unrecoverable machine check information to make the
root cause analysis easier
- Move cmpxchg_user_key() handling to uaccess library code, since the
generated code is large anyway and there is no benefit if it is
inlined
- Fix a problem when cmpxchg_user_key() is executing a code with a
non-default key: if a system is IPL-ed with "LOAD NORMAL", and the
previous system used storage keys where the fetch-protection bit was
set for some pages, and the cmpxchg_user_key() is located within such
page, a protection exception happens
- Either the external call or emergency signal order is used to send an
IPI to a remote CPU. Use the external order only, since it is at
least as good and sometimes even better, than the emergency signal
- In case of an early crash the early program check handler prints more
or less random value of the last breaking event address, since it is
not initialized properly. Copy the last breaking event address from
the lowcore to pt_regs to address this
- During STP synchronization check udelay() can not be used, since the
first CPU modifies tod_clock_base and get_tod_clock_monotonic() might
return a non-monotonic time. Instead, busy-loop on other CPUs, while
the the first CPU actually handles the synchronization operation
- When debugging the early kernel boot using QEMU with the -S flag and
GDB attached, skip the decompressor and start directly in kernel
- Rename PAI Crypto event 4210 according to z16 and z17 "z/Architecture
Principles of Operation" manual
- Remove the in-kernel time steering support in favour of the new s390
PTP driver, which allows the kernel clock steered more precisely
- Remove a possible false-positive warning in pte_free_defer(), which
could be triggered in a valid case KVM guest process is initializing
* tag 's390-6.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (29 commits)
s390/mm: Remove possible false-positive warning in pte_free_defer()
s390/stp: Default to enabled
s390/stp: Remove leap second support
s390/time: Remove in-kernel time steering
s390/sclp: Use monotonic clock in sclp_sync_wait()
s390/smp: Use monotonic clock in smp_emergency_stop()
s390/time: Use monotonic clock in get_cycles()
s390/pai_crypto: Rename PAI Crypto event 4210
scripts/gdb/symbols: make lx-symbols skip the s390 decompressor
s390/boot: Introduce jump_to_kernel() function
s390/stp: Remove udelay from stp_sync_clock()
s390/early: Copy last breaking event address to pt_regs
s390/smp: Remove conditional emergency signal order code usage
s390/uaccess: Merge cmpxchg_user_key() inline assemblies
s390/uaccess: Prevent kprobes on cmpxchg_user_key() functions
s390/uaccess: Initialize code pages executed with non-default access key
s390/skey: Provide infrastructure for executing with non-default access key
s390/uaccess: Make cmpxchg_user_key() library code
s390/page: Add memory clobber to page_set_storage_key()
s390/page: Cleanup page_set_storage_key() inline assemblies
...
When one starts QEMU with the -S flag and attaches GDB, the kernel is
not yet loaded, and the current instruction is an entry point to the
decompressor. In case the intention is to debug the early kernel boot,
and not the decompressor, e.g., put a breakpoint on some kernel
function and see all the invocations, one has to skip the decompressor.
There are many ways to do this, and so far people wrote private scripts
or memorized certain command sequences.
Make it work out of the box like this:
$ gdb -ex 'target remote :6812' -ex 'source vmlinux-gdb.py' vmlinux
Remote debugging using :6812
0x0000000000010000 in ?? ()
(gdb) lx-symbols
loading vmlinux
(gdb) x/i $pc
=> 0x3ffe0100000 <startup_continue>: lghi %r2,0
Implement this by reading the address of the jump_to_kernel() function
from the lowcore, and step until DAT is turned on.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
Tested-by: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/r/20250625154220.75300-3-iii@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
In commit 721255b982 ("genirq: Use a maple tree for interrupt descriptor
management"), the irq_desc_tree was replaced with a sparse_irqs tree using
a maple tree structure. Since the script looked for the irq_desc_tree
symbol which is no longer available, no interrupts would be printed and
the script output would not be useful anymore.
In addition to looking up the correct symbol (sparse_irqs), a new module
(mapletree.py) is added whose mtree_load() implementation is largely
copied after the C version and uses the same variable and intermediate
function names wherever possible to ensure that both the C and Python
version be updated in the future.
This restores the scripts' output to match that of /proc/interrupts.
Link: https://lkml.kernel.org/r/20250625021020.1056930-1-florian.fainelli@broadcom.com
Fixes: 721255b982 ("genirq: Use a maple tree for interrupt descriptor management")
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Shanker Donthineni <sdonthineni@nvidia.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
