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linux/arch/x86/include/asm
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Linus Torvalds 7e16838d94 i387: support lazy restore of FPU state 
This makes us recognize when we try to restore FPU state that matches
what we already have in the FPU on this CPU, and avoids the restore
entirely if so.

To do this, we add two new data fields:

 - a percpu 'fpu_owner_task' variable that gets written any time we
   update the "has_fpu" field, and thus acts as a kind of back-pointer
   to the task that owns the CPU.  The exception is when we save the FPU
   state as part of a context switch - if the save can keep the FPU
   state around, we leave the 'fpu_owner_task' variable pointing at the
   task whose FP state still remains on the CPU.

 - a per-thread 'last_cpu' field, that indicates which CPU that thread
   used its FPU on last.  We update this on every context switch
   (writing an invalid CPU number if the last context switch didn't
   leave the FPU in a lazily usable state), so we know that *that*
   thread has done nothing else with the FPU since.

These two fields together can be used when next switching back to the
task to see if the CPU still matches: if 'fpu_owner_task' matches the
task we are switching to, we know that no other task (or kernel FPU
usage) touched the FPU on this CPU in the meantime, and if the current
CPU number matches the 'last_cpu' field, we know that this thread did no
other FP work on any other CPU, so the FPU state on the CPU must match
what was saved on last context switch.

In that case, we can avoid the 'f[x]rstor' entirely, and just clear the
CR0.TS bit.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-20 10:58:54 -08:00
..
numachip x86: Add NumaChip support 2011-12-05 17:17:24 +01:00
uv x86/uv: Fix uv_gpa_to_soc_phys_ram() shift 2012-01-26 10:58:27 +01:00
visws
xen Merge branch 'upstream/xen-settime' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen 2011-11-06 20:15:05 -08:00
a.out-core.h
a.out.h
acpi.h Merge branch 'idle-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6 2011-05-29 11:18:09 -07:00
aes.h
agp.h
alternative-asm.h x86: Fix atomic64_xxx_cx8() functions 2012-01-04 15:01:56 +01:00
alternative.h asm alternatives: remove incorrect alignment notes 2011-09-15 13:28:33 -07:00
amd_nb.h x86/PCI: amd: factor out MMCONFIG discovery 2012-01-06 12:11:19 -08:00
apb_timer.h Merge branch 'timers-clocksource-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-07-23 10:34:47 -07:00
apic.h x86, x2apic: Allow "nox2apic" to disable x2apic mode setup by BIOS 2011-12-23 11:01:43 -08:00
apic_flat_64.h x86: Make flat_init_apic_ldr() available 2011-12-05 17:17:07 +01:00
apicdef.h x86, x2apic: Fallback to xapic when BIOS doesn't setup interrupt-remapping 2011-12-23 11:01:01 -08:00
apm.h
arch_hweight.h
archrandom.h x86, random: Verify RDRAND functionality and allow it to be disabled 2011-07-31 14:02:19 -07:00
asm-offsets.h
asm.h x86: Fix write lock scalability 64-bit issue 2011-07-21 09:03:36 +02:00
atomic.h x86: Use xadd helper more widely 2011-08-29 13:44:12 -07:00
atomic64_32.h x86, atomic: atomic64_read() take a const pointer 2012-01-09 19:33:24 -08:00
atomic64_64.h x86: Use xadd helper more widely 2011-08-29 13:44:12 -07:00
auxvec.h
bios_ebda.h
bitops.h x86_64, asm: Optimise fls(), ffs() and fls64() 2011-12-15 15:16:49 -08:00
bitsperlong.h
boot.h
bootparam.h x86: Add missing bzImage fields to struct setup_header 2011-12-09 17:35:33 -08:00
bug.h
bugs.h
byteorder.h
cache.h
cacheflush.h
calgary.h
calling.h x86, asm: Flip RESTORE_ARGS arguments logic 2011-06-03 14:38:53 -07:00
ce4100.h
checksum.h
checksum_32.h
checksum_64.h
clocksource.h clocksource: Change __ARCH_HAS_CLOCKSOURCE_DATA to a CONFIG option 2011-07-21 13:34:05 -07:00
cmpxchg.h x86: Properly parenthesize cmpxchg() macro arguments 2012-01-26 21:18:29 +01:00
cmpxchg_32.h x86: Fix and improve cmpxchg_double{,_local}() 2012-01-04 15:01:54 +01:00
cmpxchg_64.h x86: Fix and improve cmpxchg_double{,_local}() 2012-01-04 15:01:54 +01:00
compat.h compat: sync compat_stats with statfs. 2011-10-28 14:58:53 +02:00
cpu.h
cpufeature.h x86/amd: Add missing feature flag for fam15h models 10h-1fh processors 2012-01-26 12:06:38 +01:00
cpumask.h
cputime.h
current.h
debugreg.h x86: Add counter when debug stack is used with interrupts enabled 2011-12-21 15:38:56 -05:00
delay.h asm-generic: move archictures to common delay.h 2011-07-22 18:46:24 +02:00
desc.h x86: Keep current stack in NMI breakpoints 2011-12-21 15:38:55 -05:00
desc_defs.h
device.h iommu: Rename the DMAR and INTR_REMAP config options 2011-09-21 10:22:03 +02:00
div64.h x86/div64: Add a micro-optimization shortcut if base is power of two 2011-12-05 18:16:11 +01:00
dma-mapping.h doc: fix broken references 2011-09-27 18:08:04 +02:00
dma.h
dmi.h
dwarf2.h x86-64: Fix CFI data for interrupt frames 2011-09-28 19:04:52 +02:00
e820.h Revert "x86, efi: Calling __pa() with an ioremap()ed address is invalid" 2011-12-12 18:25:56 +01:00
edac.h
efi.h Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-01-11 19:12:33 -08:00
elf.h x86, amd: Avoid cache aliasing penalties on AMD family 15h 2011-08-05 12:26:44 -07:00
emergency-restart.h
entry_arch.h x86, mce: Replace MCE_SELF_VECTOR by irq_work 2011-06-16 12:10:08 +02:00
errno.h
fb.h
fcntl.h
fixmap.h x86/intel config: Revamp configuration to allow for Moorestown and Medfield 2011-12-18 09:17:02 +01:00
floppy.h
frame.h x86: Unify rwlock assembly implementation 2011-07-21 09:03:31 +02:00
ftrace.h ftrace/x86: mcount offset calculation 2011-05-16 14:55:57 -04:00
futex.h
gart.h
genapic.h
geode.h
gpio.h
hardirq.h x86: Convert per-cpu counter icr_read_retry_count into a member of irq_stat 2011-12-18 10:46:48 +01:00
highmem.h
hpet.h
hugetlb.h
hw_breakpoint.h
hw_irq.h iommu: Rename the DMAR and INTR_REMAP config options 2011-09-21 10:22:03 +02:00
hypertransport.h
hyperv.h Staging: hv: vmbus: Retry vmbus_post_msg() before giving up 2011-08-25 15:23:19 -07:00
hypervisor.h
i387.h i387: support lazy restore of FPU state 2012-02-20 10:58:54 -08:00
i8259.h
ia32.h
ia32_unistd.h x86: Generate system call tables and unistd_*.h from tables 2011-11-17 13:35:37 -08:00
idle.h x86 idle: clarify AMD erratum 400 workaround 2011-05-29 03:38:57 -04:00
inat.h
inat_types.h
init.h x86, mm: Unify zone_sizes_init() 2011-11-11 10:22:55 +01:00
insn.h x86, perf: Add a build-time sanity test to the x86 decoder 2011-11-10 12:38:51 +01:00
inst.h
intel_scu_ipc.h x86,mrst: Power control commands update 2011-12-05 12:42:11 +01:00
io.h x86: don't include xen/xen.h in <asm/io.h> unless XEN is enabled 2011-08-03 22:00:38 -10:00
io_apic.h x86, ioapic: Consolidate gsi routing info into 'struct ioapic' 2011-05-20 13:41:01 +02:00
ioctl.h
ioctls.h
iomap.h
iommu.h iommu: Add option to group multi-function devices 2011-11-15 12:22:31 +01:00
iommu_table.h
ipcbuf.h
ipi.h
irq.h
irq_controller.h
irq_regs.h
irq_remapping.h iommu: Rename the DMAR and INTR_REMAP config options 2011-09-21 10:22:03 +02:00
irq_vectors.h x86/irq: Standardize on CONFIG_SPARSE_IRQ=y 2011-10-13 12:12:12 +02:00
irqflags.h tracing, x86/irq: Do not trace arch_local_{*,irq_*}() functions 2011-07-07 19:22:32 +02:00
ist.h
jump_label.h
Kbuild x86: Generate system call tables and unistd_*.h from tables 2011-11-17 13:35:37 -08:00
kdebug.h ptrace: unify show_regs() prototype 2011-07-26 16:49:43 -07:00
kexec.h
kgdb.h kgdbts: unify/generalize gdb breakpoint adjustment 2011-05-26 17:12:36 -07:00
kmap_types.h
kmemcheck.h
kprobes.h
kvm.h
kvm_emulate.h KVM: x86: fix missing checks in syscall emulation 2012-02-01 11:43:40 +02:00
kvm_host.h KVM: Add generic RDPMC support 2011-12-27 11:24:35 +02:00
kvm_para.h KVM guest: KVM Steal time registration 2011-07-24 11:49:36 +03:00
ldt.h
lguest.h
lguest_hcall.h lguest: update comments 2011-07-22 14:39:50 +09:30
linkage.h x86: Get rid of asmregparm 2011-05-24 14:33:35 +02:00
local.h atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
local64.h
mach_timer.h time: x86: Remove CLOCK_TICK_RATE from mach_timer.h 2011-11-21 19:00:57 -08:00
mach_traps.h x86/mrst: Avoid reporting wrong nmi status 2011-11-10 16:21:01 +01:00
math_emu.h
mc146818rtc.h x86: Use "do { } while(0)" for empty lock_cmos()/unlock_cmos() macros 2011-12-18 09:14:31 +01:00
mca.h
mca_dma.h
mce.h mce: fix warning messages about static struct mce_device 2012-01-16 17:08:42 -08:00
microcode.h x86, microcode, AMD: Add a vendor-specific exit function 2011-12-14 12:46:47 +01:00
mman.h
mmconfig.h
mmu.h x86: Reorder mm_context_t to remove x86_64 alignment padding and thus shrink mm_struct 2011-05-25 16:16:41 +02:00
mmu_context.h atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
mmx.h
mmzone.h
mmzone_32.h x86, mm: s/PAGES_PER_ELEMENT/PAGES_PER_SECTION/ 2011-07-12 21:58:11 -07:00
mmzone_64.h Fix node_start/end_pfn() definition for mm/page_cgroup.c 2011-06-27 14:13:09 -07:00
module.h
mpspec.h
mpspec_def.h
mrst-vrtc.h
mrst.h Merge branch 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty 2012-01-09 12:09:24 -08:00
msgbuf.h
mshyperv.h
msidef.h
msr-index.h x86: TSC deadline definitions 2011-09-25 19:53:00 +03:00
msr.h x86: Document rdmsr_safe restrictions 2011-12-05 14:28:37 +01:00
mtrr.h
mutex.h
mutex_32.h
mutex_64.h
mwait.h
nmi.h x86, nmi: Add in logic to handle multiple events and unknown NMIs 2011-10-10 06:57:01 +02:00
nops.h
numa.h
numa_32.h
numa_64.h
numaq.h
olpc.h x86, olpc-xo1-sci: Add GPE handler and ebook switch functionality 2011-07-06 14:44:38 -07:00
olpc_ofw.h
page.h
page_32.h
page_32_types.h
page_64.h
page_64_types.h
page_types.h
param.h
paravirt.h KVM guest: Add a pv_ops stub for steal time 2011-07-14 12:59:44 +03:00
paravirt_types.h Merge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-tip 2011-08-12 20:46:24 -07:00
parport.h
pat.h
pci-direct.h
pci-functions.h
pci.h x86/PCI: Expand the x86_msi_ops to have a restore MSIs. 2012-01-06 14:02:26 -08:00
pci_64.h
pci_x86.h PCI: Pull PCI 'latency timer' setup up into the core 2012-01-06 12:10:42 -08:00
percpu.h Merge branch 'for-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2012-01-09 13:08:28 -08:00
perf_event.h perf events: Enable raw event support for Intel unhalted_reference_cycles event 2011-12-21 10:26:32 +01:00
perf_event_p4.h x86, perf: P4 PMU - Fix typos in comments and style cleanup 2011-07-21 20:41:54 +02:00
pgalloc.h
pgtable-2level.h
pgtable-2level_types.h
pgtable-3level.h
pgtable-3level_types.h
pgtable.h x86: Use "do { } while(0)" for empty flush_tlb_fix_spurious_fault() macro 2011-12-18 09:14:18 +01:00
pgtable_32.h
pgtable_32_types.h
pgtable_64.h
pgtable_64_types.h
pgtable_types.h x86-64: Map the HPET NX 2011-06-05 21:30:33 +02:00
poll.h
posix_types.h
posix_types_32.h
posix_types_64.h
prctl.h
probe_roms.h
processor-cyrix.h
processor-flags.h x86: Fix rflags in FAKE_STACK_FRAME 2011-12-06 10:02:38 +01:00
processor.h i387: support lazy restore of FPU state 2012-02-20 10:58:54 -08:00
prom.h atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
proto.h
ptrace-abi.h
ptrace.h x86-64: Add user_64bit_mode paravirt op 2011-08-04 16:13:49 -07:00
pvclock-abi.h
pvclock.h KVM: Fix instruction size issue in pvclock scaling 2011-08-30 14:42:30 +03:00
reboot.h x86, nmi: Wire up NMI handlers to new routines 2011-10-10 06:56:57 +02:00
reboot_fixups.h
required-features.h
resource.h
resume-trace.h
rio.h
rtc.h
rwlock.h x86: Fix write lock scalability 64-bit issue 2011-07-21 09:03:36 +02:00
rwsem.h x86: Use xadd helper more widely 2011-08-29 13:44:12 -07:00
scatterlist.h
seccomp.h
seccomp_32.h
seccomp_64.h
sections.h
segment.h x86, asm: Fix binutils 2.16 issue with __USER32_CS 2011-06-03 14:39:14 -07:00
sembuf.h
serial.h
serpent.h crypto: serpent - add 4-way parallel i586/SSE2 assembler implementation 2011-11-21 16:13:23 +08:00
setup.h x86/intel config: Revamp configuration to allow for Moorestown and Medfield 2011-12-18 09:17:02 +01:00
setup_arch.h
shmbuf.h
shmparam.h
sigcontext.h
sigcontext32.h
sigframe.h
siginfo.h
signal.h
smp.h x86, NMI: Add NMI IPI selftest 2011-12-05 12:00:16 +01:00
smpboot_hooks.h x86: Serialize SMP bootup CMOS accesses on rtc_lock 2011-07-21 09:20:59 +02:00
socket.h
sockios.h
sparsemem.h
spinlock.h x86/cmpxchg: add a locked add() helper 2011-11-25 10:42:59 -08:00
spinlock_types.h x86, ticketlock: Make __ticket_spin_trylock common 2011-08-29 13:46:34 -07:00
stackprotector.h
stacktrace.h x86: Remove warning and warning_symbol from struct stacktrace_ops 2011-05-12 15:31:28 +02:00
stat.h
statfs.h
string.h
string_32.h
string_64.h
suspend.h
suspend_32.h PM / Hibernate: Remove arch_prepare_suspend() 2011-05-24 23:35:55 +02:00
suspend_64.h PM / Hibernate: Remove arch_prepare_suspend() 2011-05-24 23:35:55 +02:00
svm.h
swab.h
swiotlb.h
sync_bitops.h
sys_ia32.h
syscall.h x86: Move <asm/asm-offsets.h> from trace_syscalls.c to asm/syscall.h 2012-01-07 14:10:18 -08:00
syscalls.h
system.h xen/pm_idle: Make pm_idle be default_idle under Xen. 2011-12-03 10:49:58 -08:00
tce.h
termbits.h
termios.h
thread_info.h i387: move TS_USEDFPU flag from thread_info to task_struct 2012-02-18 10:19:41 -08:00
time.h x86: i8253: Consolidate definitions of global_clock_event 2011-06-09 15:01:40 +02:00
timer.h sched, x86: Avoid unnecessary overflow in sched_clock 2011-11-16 19:51:25 +01:00
timex.h
tlb.h
tlbflush.h
topology.h Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci 2012-01-11 18:50:26 -08:00
trampoline.h
traps.h x86-64: Rework vsyscall emulation and add vsyscall= parameter 2011-08-10 19:26:46 -05:00
tsc.h x86, tsc: Skip TSC synchronization checks for tsc=reliable 2011-12-05 18:00:31 +01:00
types.h
uaccess.h x86-64: Set siginfo and context on vsyscall emulation faults 2011-12-05 12:17:27 +01:00
uaccess_32.h sanitize <linux/prefetch.h> usage 2011-05-20 12:50:29 -07:00
uaccess_64.h sanitize <linux/prefetch.h> usage 2011-05-20 12:50:29 -07:00
ucontext.h
unaligned.h
unistd.h x86, syscall: Need __ARCH_WANT_SYS_IPC for 32 bits 2012-01-19 12:57:09 -08:00
user.h
user32.h
user_32.h
user_64.h
vdso.h x86-64: Clean up vdso/kernel shared variables 2011-05-24 14:51:28 +02:00
vga.h
vgtod.h x86-64: Move vread_tsc and vread_hpet into the vDSO 2011-07-14 17:57:05 -07:00
virtext.h
vm86.h
vmx.h KVM: APIC: avoid instruction emulation for EOI writes 2011-09-25 19:52:17 +03:00
vsyscall.h x86-64: Rework vsyscall emulation and add vsyscall= parameter 2011-08-10 19:26:46 -05:00
vvar.h x86-64: Give vvars their own page 2011-06-05 21:30:32 +02:00
x2apic.h x86, x2apic: Move the common bits to x2apic.h 2011-05-20 13:41:11 +02:00
x86_init.h Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci 2012-01-11 18:50:26 -08:00
xcr.h
xor.h
xor_32.h
xor_64.h
xsave.h