Peter Zijlstra 15dd3a9488 hrtimer: Push reprogramming timers into the interrupt return path ... Currently hrtimer_interrupt() runs expired timers, which can re-arm themselves, after which it computes the next expiration time and re-programs the hardware. However, things like HRTICK, a highres timer driving preemption, cannot re-arm itself at the point of running, since the next task has not been determined yet. The schedule() in the interrupt return path will switch to the next task, which then causes a new hrtimer to be programmed. This then results in reprogramming the hardware at least twice, once after running the timers, and once upon selecting the new task. Notably, *both* events happen in the interrupt. By pushing the hrtimer reprogram all the way into the interrupt return path, it runs after schedule() picks the new task and the double reprogram can be avoided. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20260224163431.273488269@kernel.org		2026-02-27 16:40:14 +01:00
..
bitops	bitops: Add __attribute_const__ to generic ffs()-family implementations	2025-09-08 14:58:50 -07:00
vdso	vdso: Drop Kconfig GENERIC_VDSO_DATA_STORE	2025-09-04 11:23:50 +02:00
access_ok.h	uaccess: remove CONFIG_SET_FS	2022-02-25 09:36:06 +01:00
agp.h	char/agp: introduce asm-generic/agp.h	2023-02-13 22:13:29 +01:00
archrandom.h	random: handle archrandom with multiple longs	2022-07-25 13:26:14 +02:00
asm-offsets.h
asm-prototypes.h
atomic.h	locking/atomic: make atomic*_{cmp,}xchg optional	2023-06-05 09:57:14 +02:00
atomic64.h	atomic: specify alignment for atomic_t and atomic64_t	2026-01-26 19:07:14 -08:00
audit_change_attr.h	audit: add fchmodat2() to change attributes class	2025-12-15 14:27:18 -05:00
audit_dir_write.h
audit_read.h	audit: add missing syscalls to read class	2026-01-06 16:42:29 -05:00
audit_signal.h
audit_write.h
barrier.h	sched: Add missing memory barrier in switch_mm_cid	2024-04-16 13:59:45 +02:00
bitops.h	include: move find.h from asm_generic to linux	2022-01-15 08:47:31 -08:00
bitsperlong.h	lib: extend the scope of small_const_nbits() macro	2021-05-06 19:24:11 -07:00
bug.h	x86/bug: Implement WARN_ONCE()	2025-11-24 20:23:25 +01:00
cache.h
cacheflush.h	mm: Introduce flush_cache_vmap_early()	2023-12-14 00:23:17 -08:00
cfi.h	cfi: Flip headers	2023-12-15 16:25:55 -08:00
checksum.h	asm-generic: Improve csum_fold	2024-01-17 17:52:29 -08:00
cmpxchg-local.h	asm-generic: Fix 32 bit __generic_cmpxchg_local	2024-01-05 23:19:14 +01:00
cmpxchg.h	asm-generic: avoid __generic_cmpxchg_local warnings	2023-04-04 17:58:11 +02:00
codetag.lds.h	codetag: avoid unused alloc_tags sections/symbols	2025-07-09 22:42:14 -07:00
compat.h	asm-generic: compat: fix compat_arg_u64() and compat_arg_u64_dual()	2022-11-01 10:20:11 +11:00
current.h	asm-generic: current: Don't include thread-info.h if building asm	2023-08-26 22:38:49 +02:00
delay.h	delay: Fix ndelay() spuriously treated as udelay()	2024-11-29 11:40:22 +01:00
device.h
div64.h	__arch_xprod64(): make __always_inline when optimizing for performance	2024-10-28 21:44:28 +00:00
dma-mapping.h	dma-mapping: no need to pass a bus_type into get_arch_dma_ops()	2023-02-15 12:35:20 +01:00
dma.h
early_ioremap.h	mm/early_ioremap: add null pointer checks to prevent NULL-pointer dereference	2025-01-13 22:40:59 -08:00
emergency-restart.h
error-injection.h	docs: fault-injection: add requirements of error injectable functions	2023-02-02 22:50:00 -08:00
exec.h
extable.h
fixmap.h	fixmap: Remove unused set_fixmap_offset_io()	2024-07-11 17:41:23 +02:00
flat.h
fprobe.h	fprobe: Add fprobe_header encoding feature	2024-12-26 10:50:05 -05:00
ftrace.h
futex.h	futex: Fix additional regressions	2021-12-11 23:31:51 +01:00
getorder.h	asm-generic: force inlining of get_order() to work around gcc10 poor decision	2020-12-15 22:46:15 -08:00
hardirq.h	irqstat: Move declaration into asm-generic/hardirq.h	2020-11-23 10:31:06 +01:00
hugetlb.h	mm: correctly handle UFFD PTE markers	2025-11-24 15:08:50 -08:00
hw_irq.h
int-ll64.h
io.h	asm-generic/io.h: Skip trace helpers if rwmmio events are disabled	2025-09-24 16:21:13 +02:00
ioctl.h
iomap.h	asm-generic/io.h: rework split ioread64/iowrite64 helpers	2025-03-01 21:00:22 +01:00
irq_regs.h
irq_work.h
irq.h
irqflags.h
Kbuild	perf: Use EXPORT_SYMBOL_FOR_KVM() for the mediated APIs	2025-12-19 08:54:59 +01:00
kdebug.h
kmap_size.h	mm/highmem: Provide and use CONFIG_DEBUG_KMAP_LOCAL	2020-11-24 14:42:08 +01:00
kprobes.h	treewide: Convert macro and uses of __section(foo) to __section("foo")	2020-10-25 14:51:49 -07:00
kvm_para.h
kvm_types.h
linkage.h
local.h	locking/generic: Wire up local{,64}_try_cmpxchg()	2023-04-29 09:09:09 +02:00
local64.h	locking/generic: Wire up local{,64}_try_cmpxchg()	2023-04-29 09:09:09 +02:00
logic_io.h	logic_io instance of iounmap() needs volatile on argument	2021-12-21 21:31:08 +01:00
mcs_spinlock.h	locking: Move MCS struct definition to public header	2025-03-18 10:28:21 -07:00
memory_model.h	mm: convert page_to_section() to memdesc_section()	2025-09-13 16:55:07 -07:00
mm_hooks.h	mm: remove arch_unmap()	2024-09-01 20:26:13 -07:00
mmiowb_types.h
mmiowb.h
mmu_context.h	asm-generic: add generic MMU versions of mmu context functions	2020-10-26 16:45:03 +01:00
mmu.h
mmzone.h	arch, mm: move definition of node_data to generic code	2024-09-03 21:15:28 -07:00
module.h	asm-generic: Always define Elf_Rel and Elf_Rela	2025-03-26 15:56:43 -07:00
module.lds.h
mshyperv.h	mshv: Introduce hv_deposit_memory helper functions	2026-02-19 06:38:48 +00:00
msi.h	irqchip/gic-v5: Add GICv5 IWB support	2025-07-08 18:35:52 +01:00
nommu_context.h	asm-generic: add generic MMU versions of mmu context functions	2020-10-26 16:45:03 +01:00
numa.h	arch_numa: switch over to numa_memblks	2024-09-03 21:15:32 -07:00
param.h	alpha: regularize the situation with asm/param.h	2025-06-24 22:02:05 -04:00
parport.h
pci_iomap.h	PCI: Stub __pci_ioport_map() for arches that don't support it at all	2022-07-29 12:01:00 -05:00
pci.h	asm-generic: Add new pci.h and use it	2022-07-22 17:34:57 -05:00
percpu.h	asm-generic: percpu: Add assembly guard	2025-10-27 16:41:53 +01:00
pgalloc.h	mm: remove unnecessary __GFP_HIGHMEM in __p*d_alloc_one_*()	2025-11-20 13:43:59 -08:00
pgtable_uffd.h	mm: userfaultfd: add pgtable_supports_uffd_wp()	2025-11-24 15:08:54 -08:00
pgtable-nop4d.h	mm: rename p4d_page_vaddr to p4d_pgtable and make it return pud_t *	2021-07-08 11:48:22 -07:00
pgtable-nopmd.h	mm: recover pud_leaf() definitions in nopmd case	2024-03-13 12:12:21 -07:00
pgtable-nopud.h	mm: rename p4d_page_vaddr to p4d_pgtable and make it return pud_t *	2021-07-08 11:48:22 -07:00
preempt.h	riscv: support PREEMPT_DYNAMIC with static keys	2023-08-31 00:18:34 -07:00
qrwlock_types.h	locking/qrwlock: Change "queue rwlock" to "queued rwlock"	2022-05-11 16:27:04 +02:00
qrwlock.h	asm-generic changes for 5.19	2022-05-26 10:50:30 -07:00
qspinlock_types.h
qspinlock.h	riscv: Add qspinlock support	2024-11-11 07:33:20 -08:00
resource.h
rqspinlock.h	mm.git review status for linus..mm-nonmm-stable	2026-02-12 12:13:01 -08:00
runtime-const.h	runtime constants: add default dummy infrastructure	2024-06-19 12:34:34 -07:00
rwonce.h	rwonce: fix crash by removing READ_ONCE() for unaligned read	2025-03-26 22:16:50 +01:00
seccomp.h
sections.h	percpu: Remove __per_cpu_load	2025-02-18 10:16:00 +01:00
serial.h
set_memory.h
shmparam.h
signal.h	asm-generic: Remove empty #ifdef SA_RESTORER	2022-09-10 09:56:53 +02:00
simd.h	asm-generic: Add sched.h inclusion in simd.h	2025-05-30 20:56:48 +08:00
softirq_stack.h	asm-generic: Conditionally enable do_softirq_own_stack() via Kconfig.	2022-09-05 17:20:55 +02:00
spinlock_types.h	asm-generic: ticket-lock: Reuse arch_spinlock_t of qspinlock	2024-11-11 07:33:16 -08:00
spinlock.h	asm-generic: ticket-lock: Add separate ticket-lock.h	2024-11-11 07:33:17 -08:00
statfs.h
string.h
switch_to.h
syscall.h	syscall.h: introduce syscall_set_nr()	2025-05-11 17:48:15 -07:00
syscalls.h	syscalls: mmap(): use unsigned offset type consistently	2024-06-25 15:57:38 +02:00
text-patching.h	asm-generic: introduce text-patching.h	2024-11-07 14:25:15 -08:00
thread_info_tif.h	hrtimer: Push reprogramming timers into the interrupt return path	2026-02-27 16:40:14 +01:00
ticket_spinlock.h	riscv: Add qspinlock support	2024-11-11 07:33:20 -08:00
timex.h
tlb.h	mm: convert __HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config	2026-02-06 15:47:19 -08:00
tlbflush.h
topology.h	include/asm-generic/topology.h: Remove unused definition of cpumask_of_node()	2026-01-30 16:44:38 +01:00
trace_clock.h
uaccess.h	move asm/unaligned.h to linux/unaligned.h	2024-10-02 17:23:23 -04:00
unwind_user.h	unwind_user: Add user space unwinding API with frame pointer support	2025-07-29 14:46:07 -04:00
user.h
vermagic.h
vga.h	empty include/asm-generic/vga.h	2024-11-11 21:51:42 +01:00
video.h	arch: Rename fbdev header and source files	2024-05-03 17:07:50 +02:00
vmlinux.lds.h	fs: hide names_cache behind runtime const machinery	2026-01-13 15:17:26 -05:00
word-at-a-time.h	kernel.h: removed REPEAT_BYTE from kernel.h	2024-02-01 09:47:59 -08:00
xor.h	lib/xor: make xor prototypes more friendly to compiler vectorization	2022-02-11 20:39:39 +11:00