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31656519e1
linux/arch/x86/kernel
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Peter Zijlstra 31656519e1 sched, x86: clean up hrtick implementation 
random uvesafb failures were reported against Gentoo:

  http://bugs.gentoo.org/show_bug.cgi?id=222799

and Mihai Moldovan bisected it back to:

> 8f4d37ec07 is first bad commit
> commit 8f4d37ec07
> Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Date:   Fri Jan 25 21:08:29 2008 +0100
>
>    sched: high-res preemption tick

Linus suspected it to be hrtick + vm86 interaction and observed:

> Btw, Peter, Ingo: I think that commit is doing bad things. They aren't
> _incorrect_ per se, but they are definitely bad.
>
> Why?
>
> Using random _TIF_WORK_MASK flags is really impolite for doing
> "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S
> special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of
> vm86 mode unnecessarily.
>
> See the "work_notifysig_v86" label, and how it does that
> "save_v86_state()" thing etc etc.

Right, I never liked having to fiddle with those TIF flags. Initially I
needed it because the hrtimer base lock could not nest in the rq lock.
That however is fixed these days.

Currently the only reason left to fiddle with the TIF flags is remote
wakeups. We cannot program a remote cpu's hrtimer. I've been thinking
about using the new and improved IPI function call stuff to implement
hrtimer_start_on().

However that does require that smp_call_function_single(.wait=0) works
from interrupt context - /me looks at the latest series from Jens - Yes
that does seem to be supported, good.

Here's a stab at cleaning this stuff up ...

Mihai reported test success as well.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Mihai Moldovan <ionic@ionic.de>
Cc: Michal Januszewski <spock@gentoo.org>
Cc: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-20 10:37:28 +02:00
..
acpi Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 2008-07-16 17:25:46 -07:00
cpu Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
.gitignore arch/x86/kernel/.gitignore: Added vmlinux.lds to .gitignore file because it shouldn't be tracked. 2008-07-10 10:13:51 -07:00
alternative.c x86: fix SMP alternatives: use mutex instead of spinlock, text_poke is sleepable 2008-05-23 21:56:52 +02:00
amd_iommu_init.c x86, AMD IOMMU: remove unnecessary code from the iommu_enable function 2008-07-04 11:44:44 +02:00
amd_iommu.c x86, AMD IOMMU: flush domain TLB when there is more than one page to flush 2008-07-04 11:44:40 +02:00
aperture_64.c x86: remove end_pfn in 64bit 2008-07-08 13:10:38 +02:00
apic_32.c Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
apic_64.c x86: nmi_watchdog - use NMI_NONE by default 2008-07-08 12:51:41 +02:00
apm_32.c Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 2008-07-16 17:25:46 -07:00
asm-offsets_32.c x86/paravirt: split sysret and sysexit 2008-07-08 13:13:15 +02:00
asm-offsets_64.c x86: rename threadinfo to TI. 2008-07-09 09:14:02 +02:00
asm-offsets.c
audit_64.c
bootflag.c
cpuid.c Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
crash_dump_32.c
crash_dump_64.c
crash.c x86: allow machine_crash_shutdown to be replaced 2008-04-27 12:00:29 +03:00
doublefault_32.c
ds.c x86: debug Store - call kfree if only we really need it 2008-04-17 17:41:34 +02:00
e820.c x86, e820: remove end_user_pfn 2008-07-13 08:19:40 +02:00
early_printk.c x86, generic: mark early_printk as asmlinkage 2008-06-18 13:11:01 +02:00
early-quirks.c Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 2008-07-16 17:25:46 -07:00
efi_32.c x86: fix Intel Mac booting with EFI 2008-07-03 08:19:18 +02:00
efi_64.c x86: add flags parameter to reserve_bootmem_generic() 2008-07-08 11:49:49 +02:00
efi_stub_32.S
efi_stub_64.S
efi.c x86: introduce max_low_pfn_mapped for 64-bit 2008-07-11 10:24:04 +02:00
entry_32.S Merge branch 'auto-ftrace-next' into tracing/for-linus 2008-07-14 16:11:52 +02:00
entry_64.S Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
ftrace.c ftrace: store mcount address in rec->ip 2008-06-23 22:10:56 +02:00
genapic_64.c x86: introduce max_physical_apicid for bigsmp switching 2008-06-10 11:32:09 +02:00
genapic_flat_64.c x86: use cpumask_of_cpu() 2008-04-17 17:41:36 +02:00
genx2apic_uv_x.c x86: map UV chipset space - UV support 2008-07-09 07:43:23 +02:00
geode_32.c x86, geode: add a VSA2 ID for General Software 2008-06-19 14:19:03 +02:00
head32.c x86: extract common part of head32.c and head64.c into head.c 2008-06-05 15:10:02 +02:00
head64.c x86: move reserve_setup_data to setup.c 2008-07-08 13:16:14 +02:00
head_32.S x86: boot secondary cpus through initial_code 2008-07-08 12:48:18 +02:00
head_64.S x86: always set _PAGE_GLOBAL in _PAGE_KERNEL* flags 2008-07-08 13:16:28 +02:00
head.c x86: move reserve_setup_data to setup.c 2008-07-08 13:16:14 +02:00
hpet.c x86: make 64bit hpet_set_mapping to use ioremap too, v2 2008-07-14 09:24:17 +02:00
i386_ksyms_32.c ftrace: store mcount address in rec->ip 2008-06-23 22:10:56 +02:00
i387.c x86 ptrace: fix PTRACE_GETFPXREGS error 2008-07-01 11:03:31 +02:00
i8237.c
i8253.c x86: cleanup div_sc() usage 2008-04-26 17:35:47 +02:00
i8259.c i8259: fix final ugliness 2008-06-02 11:55:52 +02:00
init_task.c [PATCH] take init_files to fs/file.c 2008-05-16 17:22:20 -04:00
io_apic_32.c Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
io_apic_64.c Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
io_delay.c
ioport.c
ipi.c x86: ipi.c: removed duplicated include 2008-05-25 08:58:32 +02:00
irq_32.c Merge branch 'x86/irq' into x86/devel 2008-07-08 09:53:57 +02:00
irq_64.c x86: make /proc/stat account for all interrupts 2008-05-25 07:11:49 +02:00
irqinit_32.c x86: rename the i8259_32/64.c leftovers to irqinit_32/64.c 2008-05-24 16:47:39 +02:00
irqinit_64.c Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
k8.c
kdebugfs.c x86, boot: export linked list of struct setup_data via debugfs 2008-04-26 21:34:42 +02:00
kgdb.c x86: KGDB build fix 2008-04-19 19:19:54 +02:00
kprobes.c
kvm.c x86: KVM guest: hypercall batching 2008-04-27 12:00:28 +03:00
kvmclock.c x86: KVM guest: Use the paravirt clocksource structs and functions 2008-06-24 21:02:33 +03:00
ldt.c Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
machine_kexec_32.c Merge branch 'auto-ftrace-next' into tracing/for-linus 2008-07-14 16:11:52 +02:00
machine_kexec_64.c Merge branch 'auto-ftrace-next' into tracing/for-linus 2008-07-14 16:11:52 +02:00
Makefile ftrace: fix merge buglet 2008-07-17 13:26:50 +02:00
mca_32.c
mfgpt_32.c geode: fix modular build 2008-06-12 21:25:51 +02:00
microcode.c Merge branch 'for-2.6.27' of git://git.infradead.org/users/dwmw2/firmware-2.6 2008-07-14 16:54:07 -07:00
mmconf-fam10h_64.c x86: move mmconfig declarations to header 2008-05-30 15:45:17 -07:00
module_32.c
module_64.c
mpparse.c x86: add early quirk support 2008-07-10 18:55:31 +02:00
msr.c x86: cdev lock_kernel() pushdown 2008-05-18 15:43:40 -06:00
nmi.c Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
numaq_32.c x86: fix numaq_tsc_disable 2008-07-17 19:27:08 +02:00
olpc.c x86: olpc: add One Laptop Per Child architecture support 2008-04-29 08:06:07 -07:00
paravirt_patch_32.c x86/paravirt: split sysret and sysexit 2008-07-08 13:13:15 +02:00
paravirt_patch_64.c x86/paravirt: add sysret/sysexit pvops for returning to 32-bit compatibility userspace 2008-07-08 13:15:52 +02:00
paravirt.c x86: rename paravirtualized TSC functions 2008-07-09 07:43:28 +02:00
pci-calgary_64.c x86: remove end_pfn in 64bit 2008-07-08 13:10:38 +02:00
pci-dma.c x86: remove end_pfn in 64bit 2008-07-08 13:10:38 +02:00
pci-gart_64.c x86: max_low_pfn_mapped fix #4 2008-07-14 09:24:16 +02:00
pci-nommu.c x86: unify pci-nommu 2008-04-19 19:19:57 +02:00
pci-swiotlb_64.c x86: remove end_pfn in 64bit 2008-07-08 13:10:38 +02:00
pcspeaker.c
pmtimer_64.c
probe_roms_32.c x86: seperate probe_roms into another file 2008-07-08 12:50:05 +02:00
process_32.c Merge branch 'auto-ftrace-next' into tracing/for-linus 2008-07-14 16:11:52 +02:00
process_64.c Merge branch 'auto-ftrace-next' into tracing/for-linus 2008-07-14 16:11:52 +02:00
process.c ACPI : Create "idle=nomwait" bootparam 2008-07-16 23:27:05 +02:00
ptrace.c x86 ptrace: fix PTRACE_GETFPXREGS error 2008-07-01 11:03:31 +02:00
pvclock.c x86: Add structs and functions for paravirt clocksource 2008-06-24 21:02:31 +03:00
quirks.c Merge branch 'timers/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-07-15 10:39:57 -07:00
reboot_fixups_32.c x86: constify data in reboot.c 2008-05-25 08:58:30 +02:00
reboot.c x86: constify data in reboot.c 2008-05-25 08:58:30 +02:00
relocate_kernel_32.S
relocate_kernel_64.S
rtc.c provide rtc_cmos platform device 2008-06-12 18:05:42 -07:00
scx200_32.c
setup_percpu.c x86: change _node_to_cpumask_ptr to return const ptr 2008-07-13 19:11:58 +02:00
setup.c Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 2008-07-16 17:25:46 -07:00
sigframe.h
signal_32.c sched, x86: clean up hrtick implementation 2008-07-20 10:37:28 +02:00
signal_64.c sched, x86: clean up hrtick implementation 2008-07-20 10:37:28 +02:00
smp.c generic-ipi: fixlet 2008-07-06 14:01:50 +02:00
smpboot.c Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
smpcommon_32.c
smpcommon.c x86: convert to generic helpers for IPI function calls 2008-06-26 11:21:54 +02:00
stacktrace.c stacktrace: fix modular build, export print_stack_trace and save_stack_trace 2008-06-30 09:20:55 +02:00
step.c
summit_32.c x86: make generic arch support NUMAQ 2008-06-10 11:34:42 +02:00
sys_i386_32.c x86: coding style fixes to arch/x86/kernel/sys_i386_32.c 2008-06-10 12:34:54 +02:00
sys_x86_64.c unified (weak) sys_pipe implementation 2008-05-03 13:50:33 -07:00
syscall_64.c
syscall_table_32.S
tce_64.c
test_nx.c
test_rodata.c
time_32.c x86: merge sched_clock handling 2008-07-09 07:43:25 +02:00
time_64.c x86: merge tsc_init and clocksource code 2008-07-09 07:43:27 +02:00
tlb_32.c on_each_cpu(): kill unused 'retry' parameter 2008-06-26 11:24:38 +02:00
tlb_64.c Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
tlb_uv.c x86, SGI UV: uv_ptc_proc_write fix 2008-07-08 12:23:31 +02:00
tls.c
tls.h
topology.c
trampoline_32.S x86: trampoline_32.S - switch to .cpuinit.data 2008-04-26 17:35:47 +02:00
trampoline_64.S x86: move suspend wakeup code to C 2008-04-17 17:41:37 +02:00
trampoline.c x86: extend e820 ealy_res support 32bit 2008-05-25 10:55:11 +02:00
traps_32.c x86: traps_xx: various small changes 2008-07-09 08:18:31 +02:00
traps_64.c Merge branch 'x86/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-07-14 13:43:24 -07:00
tsc_sync.c
tsc.c x86: fix TSC build error on 32bit 2008-07-15 22:46:47 +02:00
verify_cpu_64.S
visws_quirks.c x86, VisWS: build fix 2008-07-10 19:45:01 +02:00
vm86_32.c
vmi_32.c x86: rename paravirtualized TSC functions 2008-07-09 07:43:28 +02:00
vmiclock_32.c x86: rename paravirtualized TSC functions 2008-07-09 07:43:28 +02:00
vmlinux_32.lds.S Merge branch 'core/rodata' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-07-14 15:28:10 -07:00
vmlinux_64.lds.S Merge branch 'core/rodata' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-07-14 15:28:10 -07:00
vmlinux.lds.S
vsmp_64.c x86: vsmp_64 add missing includes 2008-05-25 08:58:24 +02:00
vsyscall_64.c Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
x8664_ksyms_64.c Merge branch 'auto-ftrace-next' into tracing/for-linus 2008-07-14 16:11:52 +02:00