linux/arch/x86/kernel
Frederic Weisbecker e49a5bd381 perf: Use hot regs with software sched switch/migrate events
Scheduler's task migration events don't work because they always
pass NULL regs perf_sw_event(). The event hence gets filtered
in perf_swevent_add().

Scheduler's context switches events use task_pt_regs() to get
the context when the event occured which is a wrong thing to
do as this won't give us the place in the kernel where we went
to sleep but the place where we left userspace. The result is
even more wrong if we switch from a kernel thread.

Use the hot regs snapshot for both events as they belong to the
non-interrupt/exception based events family. Unlike page faults
or so that provide the regs matching the exact origin of the event,
we need to save the current context.

This makes the task migration event working and fix the context
switch callchains and origin ip.

Example: perf record -a -e cs

Before:

    10.91%      ksoftirqd/0                  0  [k] 0000000000000000
                |
                --- (nil)
                    perf_callchain
                    perf_prepare_sample
                    __perf_event_overflow
                    perf_swevent_overflow
                    perf_swevent_add
                    perf_swevent_ctx_event
                    do_perf_sw_event
                    __perf_sw_event
                    perf_event_task_sched_out
                    schedule
                    run_ksoftirqd
                    kthread
                    kernel_thread_helper

After:

    23.77%  hald-addon-stor  [kernel.kallsyms]  [k] schedule
            |
            --- schedule
               |
               |--60.00%-- schedule_timeout
               |          wait_for_common
               |          wait_for_completion
               |          blk_execute_rq
               |          scsi_execute
               |          scsi_execute_req
               |          sr_test_unit_ready
               |          |
               |          |--66.67%-- sr_media_change
               |          |          media_changed
               |          |          cdrom_media_changed
               |          |          sr_block_media_changed
               |          |          check_disk_change
               |          |          cdrom_open

v2: Always build perf_arch_fetch_caller_regs() now that software
events need that too. They don't need it from modules, unlike trace
events, so we keep the EXPORT_SYMBOL in trace_event_perf.c

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
2010-04-01 08:26:31 +02:00
..
acpi Merge branches 'battery-2.6.34', 'bugzilla-10805', 'bugzilla-14668', 'bugzilla-531916-power-state', 'ht-warn-2.6.34', 'pnp', 'processor-rename', 'sony-2.6.34', 'suse-bugzilla-531547', 'tz-check', 'video' and 'misc-2.6.34' into release 2010-03-14 21:30:17 -04:00
apic x86: Handle legacy PIC interrupts on all the cpu's 2010-03-16 06:36:35 +01:00
cpu perf: Use hot regs with software sched switch/migrate events 2010-04-01 08:26:31 +02:00
.gitignore
alternative.c Merge branch 'perf-probes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-03-05 10:50:22 -08:00
amd_iommu_init.c x86/amd-iommu: Fix IOMMU-API initialization for iommu=pt 2010-01-22 17:44:35 +01:00
amd_iommu.c x86/amd-iommu: Fix deassignment of a device from the pt_domain 2010-01-22 17:56:49 +01:00
apb_timer.c Merge branch 'x86-mrst-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-03-07 15:59:39 -08:00
aperture_64.c x86/gart: Unexport gart_iommu_aperture 2010-02-16 22:05:09 +01:00
apm_32.c x86: Remove trailing spaces in messages 2010-02-07 17:47:51 +01:00
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 Merge branch 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-02-28 11:00:55 -08:00
bootflag.c
check.c
cpuid.c x86, msr/cpuid: Pass the number of minors when unregistering MSR and CPUID drivers. 2010-01-26 23:52:38 -08:00
crash_dump_32.c x86: crash_dump: Fix non-pae kdump kernel memory accesses 2009-10-26 12:38:59 +01:00
crash_dump_64.c
crash.c x86: Use x86_platform for iommu_shutdown 2009-11-08 13:12:26 +01:00
doublefault_32.c x86: Use get_desc_base() 2009-07-19 18:27:51 +02:00
ds_selftest.c
ds_selftest.h
ds.c percpu: make percpu symbols in x86 unique 2009-10-29 22:34:14 +09:00
dumpstack_32.c perf: Drop useless check for ignored frame 2010-01-13 10:09:08 +01:00
dumpstack_64.c perf/x86-64: Use frame pointer to walk on irq and process stacks 2010-03-10 14:26:40 +01:00
dumpstack.c perf: Stop stack frame walking off kernel addresses boundaries 2010-01-13 09:32:54 +01:00
dumpstack.h perf: Introduce new perf_fetch_caller_regs() for hot regs snapshot 2010-03-10 14:39:35 +01:00
e820.c Merge branch 'linus' into x86/mm 2010-02-17 18:28:05 +01:00
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
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
efi_stub_64.S
efi.c x86: Remove trailing spaces in messages 2010-02-07 17:47:51 +01:00
entry_32.S x86, 32-bit: Use same regs as 64-bit for kernel_thread_helper 2009-12-10 15:55:36 -08:00
entry_64.S Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-12-16 12:02:37 -08:00
ftrace.c Merge branch 'tracing/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into tracing/core 2010-02-27 10:06:10 +01:00
head32.c x86: Move bios page reserve early to head32/64.c 2010-02-12 09:42:38 -08:00
head64.c x86: Use find_e820() instead of hard coded trampoline address 2009-12-11 09:28:22 +01:00
head_32.S Merge branch 'master' into percpu 2010-01-05 09:17:33 +09:00
head_64.S tree-wide: Assorted spelling fixes 2010-02-09 11:13:56 +01:00
head.c
hpet.c clocksource: add argument to resume callback 2010-02-05 14:54:10 +01:00
hw_breakpoint.c Merge branch 'perf/core' into perf/urgent 2010-03-04 11:47:52 +01:00
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, ptrace: Remove set_stopped_child_used_math() in [x]fpregs_set 2010-02-23 13:45:27 -08:00
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, pic: Fix section mismatch in legacy pic 2010-02-23 23:13:19 -08:00
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
ioport.c x86-64, paravirt: Call set_iopl_mask() on 64 bits 2009-12-09 16:54:08 -08:00
irq_32.c x86: Unify fixup_irqs() for 32-bit and 64-bit kernels 2009-11-02 15:56:34 +01:00
irq_64.c x86: Unify fixup_irqs() for 32-bit and 64-bit kernels 2009-11-02 15:56:34 +01:00
irq.c genirq: Convert irq_desc.lock to raw_spinlock 2009-12-14 23:55:33 +01:00
irqinit.c x86: Handle legacy PIC interrupts on all the cpu's 2010-03-16 06:36:35 +01:00
k8.c x86, k8 nb: Fix boot crash: enable k8_northbridges unconditionally on AMD systems 2010-03-13 08:36:16 +01:00
kdebugfs.c
kgdb.c perf, hw_breakpoint, kgdb: Do not take mutex for kernel debugger 2010-01-30 08:42:21 +01:00
kprobes.c kprobes/x86: Support kprobes jump optimization on x86 2010-02-25 17:49:26 +01:00
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 Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-12-08 13:27:33 -08:00
machine_kexec_64.c
Makefile x86, apbt: Moorestown APB system timer driver 2010-02-24 11:01:21 -08:00
mca_32.c
microcode_amd.c Revert "x86: ucode-amd: Load ucode-patches once ..." 2010-01-23 06:21:59 +01:00
microcode_core.c Revert "x86: ucode-amd: Load ucode-patches once ..." 2010-01-23 06:21:59 +01:00
microcode_intel.c x86: Remove trailing spaces in messages 2010-02-07 17:47:51 +01:00
mmconf-fam10h_64.c x86: Move range related operation to one file 2010-02-10 17:47:17 -08:00
module.c module: cleanup FIXME comments about trimming exception table entries. 2009-06-12 21:47:05 +09:30
mpparse.c x86, apic: Don't use logical-flat mode when CPU hotplug may exceed 8 CPUs 2010-02-09 20:51:11 -08:00
mrst.c x86, mrst: Platform clock setup code 2010-02-24 11:01:33 -08:00
msr.c x86, msr/cpuid: Pass the number of minors when unregistering MSR and CPUID drivers. 2010-01-26 23:52:38 -08:00
olpc.c x86, olpc: Use pci subarch init for OLPC 2010-02-25 19:26:23 -08:00
paravirt_patch_32.c
paravirt_patch_64.c
paravirt-spinlocks.c locking: Convert __raw_spin* functions to arch_spin* 2009-12-14 23:55:32 +01:00
paravirt.c x86, paravirt: Remove kmap_atomic_pte paravirt op. 2010-02-27 14:41:35 -08:00
pci-calgary_64.c tree-wide: Assorted spelling fixes 2010-02-09 11:13:56 +01:00
pci-dma.c Merge branch 'for-next' into for-linus 2010-03-08 16:55:37 +01:00
pci-gart_64.c x86, k8 nb: Fix boot crash: enable k8_northbridges unconditionally on AMD systems 2010-03-13 08:36:16 +01:00
pci-nommu.c x86: Kill bad_dma_address variable 2009-11-17 07:53:21 +01:00
pci-swiotlb.c x86: Split swiotlb initialization into two stages 2009-12-15 13:01:57 +01:00
pcspeaker.c
pmtimer_64.c
probe_roms_32.c
process_32.c Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-02-28 10:35:09 -08:00
process_64.c Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-02-28 10:35:09 -08:00
process.c x86, amd: Restrict usage of c1e_idle() 2010-03-19 14:43:36 -07:00
ptrace.c Merge branch 'for-next' into for-linus 2010-03-08 16:55:37 +01:00
pvclock.c x86: Fix warning in pvclock.c 2009-07-14 16:25:05 +02:00
quirks.c x86: Disable HPET MSI on ATI SB700/SB800 2010-01-23 06:21:58 +01:00
reboot_fixups_32.c cs5535: move the DIVIL MSR definition into linux/cs5535.h 2009-12-15 08:53:28 -08:00
reboot.c x86: Add iMac9,1 to pci_reboot_dmi_table 2010-02-17 08:08:21 +01:00
relocate_kernel_32.S
relocate_kernel_64.S
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 early_res: Add free_early_partial() 2010-02-26 08:25:35 +01:00
setup.c Merge branch 'x86-bootmem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-03-03 08:15:05 -08:00
sfi.c SFI: remove unneeded includes 2009-09-15 15:08:40 -04:00
signal.c x86: Merge sys_sigaltstack 2009-12-09 16:28:59 -08:00
smp.c Revert "x86, timers: Check for pending timers after (device) interrupts" 2009-10-09 15:58:20 +02:00
smpboot.c x86: Handle legacy PIC interrupts on all the cpu's 2010-03-16 06:36:35 +01:00
stacktrace.c perf events, x86/stacktrace: Make stack walking optional 2009-12-17 09:56:19 +01:00
step.c x86: Use get_desc_base() 2009-07-19 18:27:51 +02:00
sys_i386_32.c Add generic sys_olduname() 2010-03-12 15:52:32 -08:00
sys_x86_64.c improve sys_newuname() for compat architectures 2010-03-12 15:52:32 -08:00
syscall_64.c
syscall_table_32.S Add generic sys_old_mmap() 2010-03-12 15:52:32 -08:00
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 x86: Convert i8259_lock to raw_spinlock 2010-02-16 18:21:32 +01:00
tlb_uv.c Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-12-08 13:27:33 -08:00
tls.c
tls.h
topology.c
trampoline_32.S x86: cpuinit-annotate SMP boot trampolines properly 2009-09-20 20:23:37 +02:00
trampoline_64.S x86: Fix Suspend to RAM freeze on Acer Aspire 1511Lmi laptop 2009-10-12 18:06:48 +02:00
trampoline.c x86: Use find_e820() instead of hard coded trampoline address 2009-12-11 09:28:22 +01:00
traps.c x86/debug: Clear reserved bits of DR6 in do_debug() 2010-01-29 02:26:10 +01:00
tsc_sync.c locking: Convert __raw_spin* functions to arch_spin* 2009-12-14 23:55:32 +01:00
tsc.c Merge branch 'for-next' into for-linus 2010-03-08 16:55:37 +01:00
uv_irq.c x86, irq: Allow 0xff for /proc/irq/[n]/smp_affinity on an 8-cpu system 2009-12-17 22:03:06 -08:00
uv_sysfs.c x86: Remove trailing spaces in messages 2010-02-07 17:47:51 +01:00
uv_time.c x86, UV: Fix RTC latency bug by reading replicated cachelines 2010-01-27 11:33:53 +01:00
verify_cpu_64.S
visws_quirks.c Merge remote branch 'origin/x86/apic' into x86/mrst 2010-02-22 16:25:18 -08:00
vm86_32.c x86, 32-bit: Convert sys_vm86 & sys_vm86old 2009-12-09 16:29:23 -08:00
vmi_32.c x86, paravirt: Remove kmap_atomic_pte paravirt op. 2010-02-27 14:41:35 -08:00
vmiclock_32.c Merge branch 'for-next' into for-linus 2010-03-08 16:55:37 +01:00
vmlinux.lds.S Merge branch 'master' into percpu 2010-01-05 09:17:33 +09:00
vsmp_64.c
vsyscall_64.c x86: Raise vsyscall priority on hotplug notifier chain 2010-03-01 12:35:40 -03:00
x86_init.c Merge branch 'x86-mrst-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-03-07 15:59:39 -08:00
x8664_ksyms_64.c x86-64: Modify copy_user_generic() alternatives mechanism 2009-12-30 11:57:31 +01:00
xsave.c x86, ptrace: regset extensions to support xstate 2010-02-11 15:08:17 -08:00