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9bcbdd9c58
linux-kernel-test/arch/x86/kernel
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Arjan van de Ven 9bcbdd9c58 x86, timers: Check for pending timers after (device) interrupts 
Now that range timers and deferred timers are common, I found a
problem with these using the "perf timechart" tool. Frans Pop also
reported high scheduler latencies via LatencyTop, when using
iwlagn.

It turns out that on x86, these two 'opportunistic' timers only get
checked when another "real" timer happens. These opportunistic
timers have the objective to save power by hitchhiking on other
wakeups, as to avoid CPU wakeups by themselves as much as possible.

The change in this patch runs this check not only at timer
interrupts, but at all (device) interrupts. The effect is that:

 1) the deferred timers/range timers get delayed less

 2) the range timers cause less wakeups by themselves because
    the percentage of hitchhiking on existing wakeup events goes up.

I've verified the working of the patch using "perf timechart", the
original exposed bug is gone with this patch. Frans also reported
success - the latencies are now down in the expected ~10 msec
range.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Tested-by: Frans Pop <elendil@planet.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091008064041.67219b13@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-08 17:27:27 +02:00
..
acpi ACPI: fix Compaq Evo N800c (Pentium 4m) boot hang regression 2009-09-27 03:43:42 -04:00
apic sysctl: remove "struct file *" argument of ->proc_handler 2009-09-24 07:21:04 -07:00
cpu Revert "x86, mce: do not compile mcelog message on AMD" 2009-09-30 07:48:37 -07:00
.gitignore
alternative.c Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-14 07:57:32 -07:00
amd_iommu_init.c Merge branch 'amd-iommu/passthrough' into amd-iommu/2.6.32 2009-09-03 16:34:23 +02:00
amd_iommu.c Merge branch 'amd-iommu/pagetable' into amd-iommu/2.6.32 2009-09-03 17:14:57 +02:00
aperture_64.c kmemleak: Ignore the aperture memory hole on x86_64 2009-09-01 11:12:32 +01:00
apm_32.c Merge commit 'origin/x86/urgent' into x86/asm 2009-08-25 15:40:29 -07:00
asm-offsets_32.c lguest: optimize by coding restore_flags and irq_enable in assembler. 2009-06-12 22:27:03 +09:30
asm-offsets_64.c tracing: Define NR_syscalls for x86_64 2009-08-26 21:29:58 +02:00
asm-offsets.c
audit_64.c
bios_uv.c x86, UV: system table in bios accessed after unmap 2009-04-03 19:25:57 +02:00
bootflag.c
check.c x86: fix 64k corruption-check 2009-03-15 07:03:15 +01:00
cpuid.c Driver-Core: extend devnode callbacks to provide permissions 2009-09-19 12:50:38 -07:00
crash_dump_32.c
crash_dump_64.c
crash.c x86: disable IOMMUs on kernel crash 2009-06-15 15:20:40 +02:00
doublefault_32.c x86: Use get_desc_base() 2009-07-19 18:27:51 +02:00
ds_selftest.c x86, ds: fix buffer alignment in debug store selftest 2009-04-24 10:18:51 +02:00
ds_selftest.h x86, bts: cleanups 2009-03-13 11:57:22 +01:00
ds.c x86: ds.c fix invalid assignment 2009-06-20 17:53:13 +02:00
dumpstack_32.c headers: utsname.h redux 2009-09-23 18:13:10 -07:00
dumpstack_64.c headers: utsname.h redux 2009-09-23 18:13:10 -07:00
dumpstack.c x86: Remove duplicated #include 2009-07-11 10:17:08 +02:00
dumpstack.h x86: avoid multiple declaration of kstack_depth_to_print 2009-04-14 11:45:33 +02:00
e820.c mm: don't use alloc_bootmem_low() where not strictly needed 2009-09-22 07:17:38 -07:00
early_printk.c x86: earlyprintk: Fix regression to handle serial,ttySn as 1 arg 2009-10-01 10:34:16 +02:00
early-quirks.c x86 early quirks: eliminate unused function 2009-04-08 14:16:32 +02:00
efi_32.c
efi_64.c x86: Make 64-bit efi_ioremap use ioremap on MMIO regions 2009-08-03 13:34:25 -07:00
efi_stub_32.S Merge branch 'x86/asm' into x86/mm 2009-02-25 08:27:46 +01:00
efi_stub_64.S x86: efi_stub_32,64 - add missing ENDPROCs 2009-02-24 18:08:40 +01:00
efi.c x86: Move get/set_wallclock to x86_platform_ops 2009-09-16 14:34:50 +02:00
entry_32.S Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-06-20 10:56:46 -07:00
entry_64.S x86: ptrace: sysret path should reach syscall_trace_leave 2009-09-22 20:33:42 -07:00
ftrace.c tracing: Convert event tracing code to use NR_syscalls 2009-08-26 21:30:02 +02:00
geode_32.c
head32.c x86: Add Moorestown early detection 2009-08-31 11:09:40 +02:00
head64.c x86: Add early platform detection 2009-08-31 11:09:40 +02:00
head_32.S Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-26 10:13:35 -07:00
head_64.S Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-26 10:13:35 -07:00
head.c
hpet.c x86: hpet: Mark per cpu interrupts IRQF_TIMER to prevent resume failure 2009-06-14 18:24:29 +02:00
i386_ksyms_32.c x86: Don't generate cmpxchg8b_emu if CONFIG_X86_CMPXCHG64=y 2009-10-01 08:42:24 +02:00
i387.c x86, math-emu: fix init_fpu for task != current 2009-03-04 20:33:16 +01:00
i8237.c
i8253.c x86: Do not unregister PIT clocksource on PIT oneshot setup/shutdown 2009-08-21 21:13:37 +02:00
i8259.c x86: refactor x86_quirks support 2009-02-23 00:08:11 +01:00
init_task.c Use new __init_task_data macro in arch init_task.c files. 2009-09-21 06:27:08 +02:00
io_delay.c x86: io_delay.c cleanup 2009-03-21 16:57:04 +05:30
ioport.c x86-32: use non-lazy io bitmap context switching 2009-03-02 12:07:48 +01:00
irq_32.c x86: Use printk_once() 2009-08-09 22:28:34 +02:00
irq_64.c
irq.c x86, timers: Check for pending timers after (device) interrupts 2009-10-08 17:27:27 +02:00
irqinit.c perf: Do the big rename: Performance Counters -> Performance Events 2009-09-21 14:28:04 +02:00
k8.c
kdebugfs.c x86: kdebugfs.c cleanup 2009-03-21 16:55:45 +05:30
kgdb.c Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-06-10 15:49:10 -07:00
kprobes.c Merge branch 'tracing/core-v2' into tracing-for-linus 2009-04-02 00:49:02 +02:00
kvm.c KVM guest: do not batch pte updates from interrupt context 2009-09-10 18:10:50 +03:00
kvmclock.c Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-18 14:05:47 -07:00
ldt.c cpumask: use mm_cpumask() wrapper: x86 2009-09-24 09:34:52 +09:30
machine_kexec_32.c x86, kexec: fix crashdump panic with CONFIG_KEXEC_JUMP 2009-05-07 22:01:05 -07:00
machine_kexec_64.c x86, kexec: fix crashdump panic with CONFIG_KEXEC_JUMP 2009-05-07 22:01:05 -07:00
Makefile Merge branch 'linus' into sfi-release 2009-09-19 00:11:26 -04:00
mca_32.c x86: refactor x86_quirks support 2009-02-23 00:08:11 +01:00
mfgpt_32.c x86: geode: Mark mfgpt irq IRQF_TIMER to prevent resume failure 2009-07-24 08:42:52 +02:00
microcode_amd.c x86, microcode: Simplify vfree() use 2009-06-07 16:35:11 +02:00
microcode_core.c mm: replace various uses of num_physpages by totalram_pages 2009-09-22 07:17:38 -07:00
microcode_intel.c x86: microcode: use smp_call_function_single instead of set_cpus_allowed, cleanup of synchronization logic 2009-05-12 10:36:44 +02:00
mmconf-fam10h_64.c x86: move various CPU initialization objects into .cpuinit.rodata 2009-03-12 13:13:07 +01:00
module.c module: cleanup FIXME comments about trimming exception table entries. 2009-06-12 21:47:05 +09:30
mpparse.c Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-18 14:05:47 -07:00
mrst.c x86: Add Moorestown early detection 2009-08-31 11:09:40 +02:00
msr.c Driver-Core: extend devnode callbacks to provide permissions 2009-09-19 12:50:38 -07:00
olpc.c
paravirt_patch_32.c
paravirt_patch_64.c
paravirt-spinlocks.c
paravirt.c Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-18 14:05:47 -07:00
pci-calgary_64.c x86: calgary: remove IOMMU_DEBUG 2009-04-14 13:03:36 +02:00
pci-dma.c Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 2009-09-16 07:49:54 -07:00
pci-gart_64.c x86: replace is_buffer_dma_capable() with dma_capable 2009-07-28 14:19:19 +09:00
pci-nommu.c dma-ops: Remove flush_write_buffers() in dma-mapping-common.h 2009-08-10 09:34:57 +02:00
pci-swiotlb.c Merge git://git.infradead.org/iommu-2.6 2009-09-23 10:06:10 -07:00
pcspeaker.c
pmtimer_64.c
probe_roms_32.c
process_32.c Merge branch 'x86-percpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-14 08:01:28 -07:00
process_64.c Merge branch 'x86-percpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-14 08:01:28 -07:00
process.c cpumask: use zalloc_cpumask_var() where possible 2009-09-24 09:34:24 +09:30
ptrace.c x86: ptrace: set TS_COMPAT when 32-bit ptrace sets orig_eax>=0 2009-09-22 22:49:24 -07:00
pvclock.c x86: Fix warning in pvclock.c 2009-07-14 16:25:05 +02:00
quirks.c x86/PCI: pci quirks, fix pci refcounting 2009-09-09 14:11:02 -07:00
reboot_fixups_32.c
reboot.c Merge commit 'v2.6.31-rc8' into x86/txt 2009-09-02 08:17:56 +02:00
relocate_kernel_32.S x86, kexec: fix kexec x86 coding style 2009-03-10 18:13:25 -07:00
relocate_kernel_64.S x86, kexec: x86_64: add kexec jump support for x86_64 2009-03-10 18:13:25 -07:00
rtc.c Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-18 14:05:47 -07:00
scx200_32.c
setup_percpu.c x86,percpu: use embedding for 64bit NUMA and page for 32bit NUMA 2009-08-14 15:00:52 +09:00
setup.c Merge branch 'sfi-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-sfi-2.6 2009-09-23 09:34:07 -07:00
sfi.c SFI: remove unneeded includes 2009-09-15 15:08:40 -04:00
signal.c Merge branch 'x86-mce-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-17 21:07:08 -07:00
smp.c x86, timers: Check for pending timers after (device) interrupts 2009-10-08 17:27:27 +02:00
smpboot.c cpumask: use zalloc_cpumask_var() where possible 2009-09-24 09:34:24 +09:30
stacktrace.c x86: add save_stack_trace_bp() for tracing from a specific stack frame 2009-06-12 23:01:05 +02:00
step.c x86: Use get_desc_base() 2009-07-19 18:27:51 +02:00
sys_i386_32.c
sys_x86_64.c tracing: Convert x86_64 mmap and uname to use DEFINE_SYSCALL 2009-08-11 20:35:29 +02:00
syscall_64.c
syscall_table_32.S perf: Do the big rename: Performance Counters -> Performance Events 2009-09-21 14:28:04 +02:00
tboot.c x86, intel_txt: clean up the impact on generic code, unbreak non-x86 2009-09-01 18:25:07 -07:00
tce_64.c
test_nx.c
test_rodata.c
time.c cpumask: remove last assignment to mask field of struct irqaction. 2009-09-24 09:34:37 +09:30
tlb_uv.c x86: uv: Clean up uv_ptc_init(), use proc_create() 2009-08-24 12:26:46 +02:00
tls.c
tls.h
topology.c x86: topology.c cleanup 2009-03-21 16:55:24 +05:30
trampoline_32.S x86: cpuinit-annotate SMP boot trampolines properly 2009-09-20 20:23:37 +02:00
trampoline_64.S x86: cpuinit-annotate SMP boot trampolines properly 2009-09-20 20:23:37 +02:00
trampoline.c x86: cpuinit-annotate SMP boot trampolines properly 2009-09-20 20:23:37 +02:00
traps.c Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-26 10:13:35 -07:00
tsc_sync.c x86: Reduce verbosity of "TSC is reliable" message 2009-09-24 11:35:19 +02:00
tsc.c Merge branch 'linus' into x86/urgent 2009-09-20 20:25:03 +02:00
uv_irq.c
uv_sysfs.c x86: prevent /sys/firmware/sgi_uv from being created on non-uv systems 2009-04-08 14:58:10 +02:00
uv_time.c uv_time: add parameter to uv_read_rtc() 2009-04-22 17:41:25 +02:00
verify_cpu_64.S
visws_quirks.c x86: Add timer_init to x86_init_ops 2009-08-31 09:35:46 +02:00
vm86_32.c Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-06-10 16:15:14 -07:00
vmi_32.c x86: Move get/set_wallclock to x86_platform_ops 2009-09-16 14:34:50 +02:00
vmiclock_32.c x86: Move tsc_calibration to x86_init_ops 2009-08-31 09:35:47 +02:00
vmlinux.lds.S Merge branch 'x86/asm' into x86/urgent 2009-09-25 10:47:00 +02:00
vsmp_64.c Revert "x86: don't compile vsmp_64 for 32bit" 2009-03-25 21:34:28 +01:00
vsyscall_64.c sysctl: remove "struct file *" argument of ->proc_handler 2009-09-24 07:21:04 -07:00
x86_init.c x86: Move get/set_wallclock to x86_platform_ops 2009-09-16 14:34:50 +02:00
x8664_ksyms_64.c
xsave.c x86-64: fix FPU corruption with signals and preemption 2009-04-20 14:33:00 -07:00