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Jeremy Fitzhardinge db949bba3c x86-32: use non-lazy io bitmap context switching 
Impact: remove 32-bit optimization to prepare unification

x86-32 and -64 differ in the way they context-switch tasks
with io permission bitmaps.  x86-64 simply copies the next
tasks io bitmap into place (if any) on context switch.  x86-32
invalidates the bitmap on context switch, so that the next
IO instruction will fault; at that point it installs the
appropriate IO bitmap.

This makes context switching IO-bitmap-using tasks a bit more
less expensive, at the cost of making the next IO instruction
slower due to the extra fault.  This tradeoff only makes sense
if IO-bitmap-using processes are relatively common, but they
don't actually use IO instructions very often.

However, in a typical desktop system, the only process likely
to be using IO bitmaps is the X server, and nothing at all on
a server.  Therefore the lazy context switch doesn't really win
all that much, and its just a gratuitious difference from
64-bit code.

This patch removes the lazy context switch, with a view to
unifying this code in a later change.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-02 12:07:48 +01:00
..
acpi Merge branches 'x86/acpi', 'x86/apic', 'x86/asm', 'x86/cleanups', 'x86/mm', 'x86/signal' and 'x86/urgent'; commit 'v2.6.29-rc6' into x86/core 2009-02-24 21:50:43 +01:00
apic x86_32: summit_32, de-inline functions 2009-02-24 22:07:51 +01:00
cpu Merge branches 'x86/acpi', 'x86/apic', 'x86/asm', 'x86/cleanups', 'x86/mm', 'x86/signal' and 'x86/urgent'; commit 'v2.6.29-rc6' into x86/core 2009-02-24 21:50:43 +01:00
.gitignore
alternative.c x86: make vmap yell louder when it is used under irqs_disabled() 2009-02-25 16:38:34 +01:00
amd_iommu_init.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu 2009-01-03 12:03:52 -08:00
amd_iommu.c AMD IOMMU: remove now unnecessary #ifdefs 2009-01-03 16:44:15 +01:00
aperture_64.c aperture_64.c: clarify that too small aperture is valid reason for this code 2008-11-28 15:24:39 +01:00
apm_32.c Merge branch 'linus' into x86/apic 2009-02-22 20:05:19 +01:00
asm-offsets_32.c x86: make lazy %gs optional on x86_32 2009-02-10 00:42:00 +01:00
asm-offsets_64.c x86: remove pda.h 2009-01-20 12:29:20 +09:00
asm-offsets.c
audit_64.c
bios_uv.c x86: bios_uv.c: uv_systab should be static 2008-12-29 22:08:28 -08:00
bootflag.c
check.c x86: corruption-check: some post-move cleanups 2008-10-27 18:09:45 +01:00
cpuid.c Merge branch 'cpus4096-for-linus-3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-01-03 12:04:39 -08:00
crash_dump_32.c kdump: make elfcorehdr_addr independent of CONFIG_PROC_VMCORE 2008-10-20 08:52:39 -07:00
crash_dump_64.c kdump: make elfcorehdr_addr independent of CONFIG_PROC_VMCORE 2008-10-20 08:52:39 -07:00
crash.c x86, apic: remove duplicate asm/apic.h inclusions 2009-02-17 17:52:44 +01:00
doublefault_32.c x86: fix virt_addr_valid() with CONFIG_DEBUG_VIRTUAL=y, v2 2008-10-13 10:33:15 +02:00
ds.c x86, ds, bts: cleanup/fix DS configuration 2009-01-22 14:35:00 +01:00
dumpstack_32.c ftrace: print real return in dumpstack for function graph 2008-12-03 08:56:25 +01:00
dumpstack_64.c x86-64: Move current task from PDA to per-cpu and consolidate with 32-bit. 2009-01-19 00:38:58 +09:00
dumpstack.c x86: don't pretend that non-framepointer stack traces are reliable 2009-02-09 09:45:29 +01:00
dumpstack.h ftrace: print real return in dumpstack for function graph 2008-12-03 08:56:25 +01:00
e820.c x86: check range in reserve_early() 2009-02-24 22:43:15 +01:00
early_printk.c x86: early_printk.c - fix pgtable.h unification fallout 2009-02-09 11:32:17 +01:00
early-quirks.c x86: only scan the root bus in early PCI quirks 2009-01-09 12:46:22 -08:00
efi_32.c
efi_64.c x86: remove include of apic.h from hardirq_64.h 2009-01-23 11:03:29 +09:00
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: make UV support configurable 2009-01-21 13:00:42 +01:00
entry_32.S x86: minor cleanup in the espfix code 2009-02-23 11:34:04 -08:00
entry_64.S Merge branch 'x86/asm' into x86/mm 2009-02-25 08:27:46 +01:00
ftrace.c tracing, x86: fix constraint for parent variable 2009-02-11 10:06:13 +01:00
geode_32.c
head32.c x86: change static allocation of trampoline area 2008-12-08 13:49:45 +01:00
head64.c x86: remove pda_init() 2009-01-20 12:29:19 +09:00
head_32.S x86: use _types.h headers in asm where available 2009-02-13 11:35:01 -08:00
head_64.S x86: head_64.S - use IDT_ENTRIES instead of hardcoded number 2009-02-24 18:08:38 +01:00
head.c x86, debug: remove EBDA debug printk 2008-12-12 11:08:42 +01:00
hpet.c Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-02-17 14:27:39 -08:00
i386_ksyms_32.c ftrace: rename FTRACE to FUNCTION_TRACER 2008-10-20 18:27:03 +02:00
i387.c x86: fix __cpuinit/__init tangle in init_thread_xstate() 2008-11-20 16:43:41 +01:00
i8237.c i8327: fix outb() parameter order 2009-02-10 13:13:23 +01:00
i8253.c cpumask: convert struct clock_event_device to cpumask pointers. 2008-12-13 21:20:26 +10:30
i8259.c x86: refactor x86_quirks support 2009-02-23 00:08:11 +01:00
init_task.c take init_fs to saner place 2008-12-31 18:07:42 -05:00
io_delay.c
ioport.c x86-32: use non-lazy io bitmap context switching 2009-03-02 12:07:48 +01:00
irq_32.c x86, apic: remove duplicate asm/apic.h inclusions 2009-02-17 17:52:44 +01:00
irq_64.c x86: unify do_IRQ() 2009-02-09 12:16:05 +01:00
irq.c x86, apic: remove genapic.h 2009-02-17 17:52:44 +01:00
irqinit_32.c x86: refactor x86_quirks support 2009-02-23 00:08:11 +01:00
irqinit_64.c x86: irqinit_64.c init_ISA_irqs should be static 2009-01-04 18:19:41 +01:00
k8.c x86, gart: fix gart detection for Fam11h CPUs 2008-10-28 17:10:27 +01:00
kdebugfs.c
kgdb.c x86, apic: remove genapic.h 2009-02-17 17:52:44 +01:00
kprobes.c kprobes: check CONFIG_FREEZER instead of CONFIG_PM 2009-01-16 14:32:17 -05:00
kvm.c
kvmclock.c x86: refactor x86_quirks support 2009-02-23 00:08:11 +01:00
ldt.c x86: ldt.c fix style problems 2009-01-02 17:46:24 +01:00
machine_kexec_32.c x86: kexec/i386: fix sparse warnings: Using plain integer as NULL pointer 2009-02-22 09:27:11 +01:00
machine_kexec_64.c x86: kexec: Use one page table in x86_64 machine_kexec 2009-02-03 18:29:18 -08:00
Makefile x86, apic: separate 32-bit setup functionality out of apic_32.c 2009-02-17 23:12:48 +01:00
mca_32.c x86: refactor x86_quirks support 2009-02-23 00:08:11 +01:00
mfgpt_32.c trivial: fix then -> than typos in comments and documentation 2009-01-06 11:28:06 +01:00
microcode_amd.c x86: fix warning in arch/x86/kernel/microcode_amd.c 2008-12-19 01:31:54 +01:00
microcode_core.c Merge branches 'x86/apic', 'x86/cleanups', 'x86/cpufeature', 'x86/crashdump', 'x86/debug', 'x86/defconfig', 'x86/detect-hyper', 'x86/doc', 'x86/dumpstack', 'x86/early-printk', 'x86/fpu', 'x86/idle', 'x86/io', 'x86/memory-corruption-check', 'x86/microcode', 'x86/mm', 'x86/mtrr', 'x86/nmi-watchdog', 'x86/pat2', 'x86/pci-ioapic-boot-irq-quirks', 'x86/ptrace', 'x86/quirks', 'x86/reboot', 'x86/setup-memory', 'x86/signal', 'x86/sparse-fixes', 'x86/time', 'x86/uv' and 'x86/xen' into x86/core 2008-12-23 16:27:23 +01:00
microcode_intel.c x86: microcode_intel.c fix style problems 2009-01-12 11:22:40 +01:00
mmconf-fam10h_64.c x86, pci: move arch/x86/pci/pci.h to arch/x86/include/asm/pci_x86.h 2008-12-29 18:17:36 +01:00
module_32.c x86: module_32.c fix style problems 2009-01-12 11:22:55 +01:00
module_64.c x86: module_64.c fix style problems 2009-01-12 11:23:01 +01:00
mpparse.c x86: check mptable physptr with max_low_pfn on 32bit 2009-02-23 07:41:31 +01:00
msr.c x86: msr.c fix style problems 2009-01-12 11:22:50 +01:00
olpc.c x86, olpc: fix model detection without OFW 2009-02-14 23:05:25 +01:00
paravirt_patch_32.c x86/pvops: add a paravirt_ident functions to allow special patching 2009-01-30 14:51:44 -08:00
paravirt_patch_64.c x86/pvops: add a paravirt_ident functions to allow special patching 2009-01-30 14:51:44 -08:00
paravirt-spinlocks.c x86: remove byte locks 2009-01-20 17:14:28 +01:00
paravirt.c x86: refactor x86_quirks support 2009-02-23 00:08:11 +01:00
pci-calgary_64.c arch/x86/kernel/pci-calgary_64.c: change simple_strtol to simple_strtoul 2008-11-25 15:56:03 +01:00
pci-dma.c PCI: struct device - replace bus_id with dev_name(), dev_set_name() 2009-01-07 11:12:23 -08:00
pci-gart_64.c Documentation: move DMA-mapping.txt to Doc/PCI/ 2009-01-29 18:19:29 -08:00
pci-nommu.c
pci-swiotlb_64.c Merge branch 'core/iommu' into core/urgent 2009-01-05 14:17:24 +01:00
pcspeaker.c
pmtimer_64.c
probe_roms_32.c x86: move mach-default/*.h files to asm/ 2009-01-29 14:16:51 +01:00
process_32.c x86-32: use non-lazy io bitmap context switching 2009-03-02 12:07:48 +01:00
process_64.c x86: fix x86_32 stack protector bugs 2009-02-11 11:33:49 +01:00
process.c Merge branch 'linus' into x86/apic 2009-02-13 09:44:22 +01:00
ptrace.c x86, mm: rename TASK_SIZE64 => TASK_SIZE_MAX 2009-02-21 00:09:44 +01:00
pvclock.c x86: pvclock: fix shadowed variable warning 2008-10-15 14:25:14 +02:00
quirks.c x86: enable HPET on Fujitsu u9200 2008-12-16 20:36:44 +01:00
reboot_fixups_32.c
reboot.c x86, apic: remove duplicate asm/apic.h inclusions 2009-02-17 17:52:44 +01:00
relocate_kernel_32.S x86: use _types.h headers in asm where available 2009-02-13 11:35:01 -08:00
relocate_kernel_64.S x86: use _types.h headers in asm where available 2009-02-13 11:35:01 -08:00
rtc.c rtc: use bcd2bin/bin2bcd 2008-10-20 08:52:41 -07:00
scx200_32.c
setup_percpu.c x86: implement x86_32 stack protector 2009-02-10 00:42:01 +01:00
setup.c x86: refactor x86_quirks support 2009-02-23 00:08:11 +01:00
signal.c x86: merge sys_rt_sigreturn between 32 and 64 bits 2009-02-11 16:31:40 -08:00
smp.c x86, apic: remove genapic.h 2009-02-17 17:52:44 +01:00
smpboot.c x86, apic: remove ->store_NMI_vector() 2009-02-17 17:53:56 +01:00
stacktrace.c x86: update copyrights 2009-01-31 04:21:18 +01:00
step.c
sys_i386_32.c
sys_x86_64.c
syscall_64.c x86: Fix ASM_X86__ header guards 2008-10-22 22:55:23 -07:00
syscall_table_32.S x86: pass in pt_regs pointer for syscalls that need it 2009-02-11 12:40:45 +01:00
tce_64.c
test_nx.c
test_rodata.c
time_32.c x86: refactor x86_quirks support 2009-02-23 00:08:11 +01:00
time_64.c x86: Add IRQF_TIMER to legacy x86 timer interrupt descriptors 2009-02-22 10:27:49 -08:00
tlb_uv.c x86, apic: remove duplicate asm/apic.h inclusions 2009-02-17 17:52:44 +01:00
tls.c
tls.h
topology.c
trampoline_32.S x86: use _types.h headers in asm where available 2009-02-13 11:35:01 -08:00
trampoline_64.S x86: use _types.h headers in asm where available 2009-02-13 11:35:01 -08:00
trampoline.c x86: change static allocation of trampoline area 2008-12-08 13:49:45 +01:00
traps.c x86-32: use non-lazy io bitmap context switching 2009-03-02 12:07:48 +01:00
tsc_sync.c Merge branches 'x86/apic', 'x86/cleanups', 'x86/cpufeature', 'x86/crashdump', 'x86/debug', 'x86/defconfig', 'x86/detect-hyper', 'x86/doc', 'x86/dumpstack', 'x86/early-printk', 'x86/fpu', 'x86/idle', 'x86/io', 'x86/memory-corruption-check', 'x86/microcode', 'x86/mm', 'x86/mtrr', 'x86/nmi-watchdog', 'x86/pat2', 'x86/pci-ioapic-boot-irq-quirks', 'x86/ptrace', 'x86/quirks', 'x86/reboot', 'x86/setup-memory', 'x86/signal', 'x86/sparse-fixes', 'x86/time', 'x86/uv' and 'x86/xen' into x86/core 2008-12-23 16:27:23 +01:00
tsc.c x86: replace CONFIG_X86_SMP with CONFIG_SMP 2009-01-29 14:17:00 +01:00
uv_irq.c x86, apic: remove genapic.h 2009-02-17 17:52:44 +01:00
uv_sysfs.c x86: Add sysfs entries for UV v4 2008-10-16 16:53:13 +02:00
verify_cpu_64.S
visws_quirks.c x86: refactor x86_quirks support 2009-02-23 00:08:11 +01:00
vm86_32.c x86: use regparm(3) for passed-in pt_regs pointer 2009-02-11 14:00:56 -08:00
vmi_32.c x86, apic: remove genapic.h 2009-02-17 17:52:44 +01:00
vmiclock_32.c Merge branches 'x86/acpi', 'x86/apic', 'x86/asm', 'x86/cleanups', 'x86/mm', 'x86/signal' and 'x86/urgent'; commit 'v2.6.29-rc6' into x86/core 2009-02-24 21:50:43 +01:00
vmlinux_32.lds.S x86: use _types.h headers in asm where available 2009-02-13 11:35:01 -08:00
vmlinux_64.lds.S x86: use _types.h headers in asm where available 2009-02-13 11:35:01 -08:00
vmlinux.lds.S
vsmp_64.c x86/paravirt: add register-saving thunks to reduce caller register pressure 2009-01-30 14:51:45 -08:00
vsyscall_64.c Merge branch 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-12-28 12:21:10 -08:00
x8664_ksyms_64.c x86: convert pda ops to wrappers around x86 percpu accessors 2009-01-16 14:20:22 +01:00
xsave.c x86: xsave.c: restore_user_xstate should be static 2008-12-30 13:31:41 -08:00