06 Mar, 2010

1 commit

  • …nel/git/tip/linux-2.6-tip

    * 'perf-probes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
    x86: Issue at least one memory barrier in stop_machine_text_poke()
    perf probe: Correct probe syntax on command line help
    perf probe: Add lazy line matching support
    perf probe: Show more lines after last line
    perf probe: Check function address range strictly in line finder
    perf probe: Use libdw callback routines
    perf probe: Use elfutils-libdw for analyzing debuginfo
    perf probe: Rename probe finder functions
    perf probe: Fix bugs in line range finder
    perf probe: Update perf probe document
    perf probe: Do not show --line option without dwarf support
    kprobes: Add documents of jump optimization
    kprobes/x86: Support kprobes jump optimization on x86
    x86: Add text_poke_smp for SMP cross modifying code
    kprobes/x86: Cleanup save/restore registers
    kprobes/x86: Boost probes when reentering
    kprobes: Jump optimization sysctl interface
    kprobes: Introduce kprobes jump optimization
    kprobes: Introduce generic insn_slot framework
    kprobes/x86: Cleanup RELATIVEJUMP_INSTRUCTION to RELATIVEJUMP_OPCODE

    Linus Torvalds
     

01 Mar, 2010

1 commit

  • …el/git/tip/linux-2.6-tip

    * 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (28 commits)
    ftrace: Add function names to dangling } in function graph tracer
    tracing: Simplify memory recycle of trace_define_field
    tracing: Remove unnecessary variable in print_graph_return
    tracing: Fix typo of info text in trace_kprobe.c
    tracing: Fix typo in prof_sysexit_enable()
    tracing: Remove CONFIG_TRACE_POWER from kernel config
    tracing: Fix ftrace_event_call alignment for use with gcc 4.5
    ftrace: Remove memory barriers from NMI code when not needed
    tracing/kprobes: Add short documentation for HAVE_REGS_AND_STACK_ACCESS_API
    s390: Add pt_regs register and stack access API
    tracing/kprobes: Make Kconfig dependencies generic
    tracing: Unify arch_syscall_addr() implementations
    tracing: Add notrace to TRACE_EVENT implementation functions
    ftrace: Allow to remove a single function from function graph filter
    tracing: Add correct/incorrect to sort keys for branch annotation output
    tracing: Simplify test for function_graph tracing start point
    tracing: Drop the tr check from the graph tracing path
    tracing: Add stack dump to trace_printk if stacktrace option is set
    tracing: Use appropriate perl constructs in recordmcount.pl
    tracing: optimize recordmcount.pl for offsets-handling
    ...

    Linus Torvalds
     

26 Feb, 2010

4 commits

  • OProfile support for IBS is now for several versions in the
    kernel. The feature is stable now and the code can be activated
    permanently.

    As a side effect IBS now works also on nosmp configs.

    Signed-off-by: Robert Richter

    Robert Richter
     
  • OProfile is already used for a long time and no longer experimental.

    Signed-off-by: Robert Richter

    Robert Richter
     
  • The commit

    1155de4 ring-buffer: Make it generally available

    already made ring-buffer available without the TRACING option
    enabled. This patch removes the TRACING dependency from oprofile.

    Fixes also oprofile configuration on ia64.

    The patch also applies to the 2.6.32-stable kernel.

    Reported-by: Tony Jones
    Cc: stable@kernel.org
    Signed-off-by: Robert Richter

    Robert Richter
     
  • Introduce kprobes jump optimization arch-independent parts.
    Kprobes uses breakpoint instruction for interrupting execution
    flow, on some architectures, it can be replaced by a jump
    instruction and interruption emulation code. This gains kprobs'
    performance drastically.

    To enable this feature, set CONFIG_OPTPROBES=y (default y if the
    arch supports OPTPROBE).

    Changes in v9:
    - Fix a bug to optimize probe when enabling.
    - Check nearby probes can be optimize/unoptimize when disarming/arming
    kprobes, instead of registering/unregistering. This will help
    kprobe-tracer because most of probes on it are usually disabled.

    Changes in v6:
    - Cleanup coding style for readability.
    - Add comments around get/put_online_cpus().

    Changes in v5:
    - Use get_online_cpus()/put_online_cpus() for avoiding text_mutex
    deadlock.

    Signed-off-by: Masami Hiramatsu
    Cc: systemtap
    Cc: DLE
    Cc: Ananth N Mavinakayanahalli
    Cc: Jim Keniston
    Cc: Srikar Dronamraju
    Cc: Christoph Hellwig
    Cc: Steven Rostedt
    Cc: Frederic Weisbecker
    Cc: Anders Kaseorg
    Cc: Tim Abbott
    Cc: Andi Kleen
    Cc: Jason Baron
    Cc: Mathieu Desnoyers
    Cc: Frederic Weisbecker
    Cc: Ananth N Mavinakayanahalli
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Masami Hiramatsu
     

23 Feb, 2010

1 commit


17 Feb, 2010

1 commit

  • KPROBES_EVENT actually depends on the regs and stack access API
    (b1cf540f) and not on x86.
    So introduce a new config option which architectures can select if
    they have the API implemented and switch x86.

    Signed-off-by: Heiko Carstens
    Acked-by: Masami Hiramatsu
    Cc: Ingo Molnar
    Cc: Martin Schwidefsky
    LKML-Reference:
    Signed-off-by: Frederic Weisbecker

    Heiko Carstens
     

18 Dec, 2009

1 commit

  • The kbuild's select command doesn't propagate through the config
    dependencies.

    Hence the current rules of hardware breakpoint's config can't
    ensure perf can never be disabled under us.

    We have:

    config X86
    selects HAVE_HW_BREAKPOINTS

    config HAVE_HW_BREAKPOINTS
    select PERF_EVENTS

    config PERF_EVENTS
    [...]

    x86 will select the breakpoints but that won't propagate to perf
    events. The user can still disable the latter, but it is
    necessary for the breakpoints.

    What we need is:

    - x86 selects HAVE_HW_BREAKPOINTS and PERF_EVENTS
    - HAVE_HW_BREAKPOINTS depends on PERF_EVENTS

    so that we ensure PERF_EVENTS is enabled and frozen for x86.

    This fixes the following kind of build errors:

    In file included from arch/x86/kernel/hw_breakpoint.c:31:
    include/linux/hw_breakpoint.h: In function 'hw_breakpoint_addr':
    include/linux/hw_breakpoint.h:39: error: 'struct perf_event' has no member named 'attr'

    v2: Select also ANON_INODES from x86, required for perf

    Reported-by: Cyrill Gorcunov
    Reported-by: Michal Marek
    Reported-by: Andrew Randrianasulu
    Signed-off-by: Frederic Weisbecker
    Cc: Peter Zijlstra
    Cc: Arnaldo Carvalho de Melo
    Cc: Paul Mackerras
    Cc: Randy Dunlap
    Cc: K.Prasad
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Frederic Weisbecker
     

09 Dec, 2009

1 commit

  • * 'kvm-updates/2.6.33' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (84 commits)
    KVM: VMX: Fix comparison of guest efer with stale host value
    KVM: s390: Fix prefix register checking in arch/s390/kvm/sigp.c
    KVM: Drop user return notifier when disabling virtualization on a cpu
    KVM: VMX: Disable unrestricted guest when EPT disabled
    KVM: x86 emulator: limit instructions to 15 bytes
    KVM: s390: Make psw available on all exits, not just a subset
    KVM: x86: Add KVM_GET/SET_VCPU_EVENTS
    KVM: VMX: Report unexpected simultaneous exceptions as internal errors
    KVM: Allow internal errors reported to userspace to carry extra data
    KVM: Reorder IOCTLs in main kvm.h
    KVM: x86: Polish exception injection via KVM_SET_GUEST_DEBUG
    KVM: only clear irq_source_id if irqchip is present
    KVM: x86: disallow KVM_{SET,GET}_LAPIC without allocated in-kernel lapic
    KVM: x86: disallow multiple KVM_CREATE_IRQCHIP
    KVM: VMX: Remove vmx->msr_offset_efer
    KVM: MMU: update invlpg handler comment
    KVM: VMX: move CR3/PDPTR update to vmx_set_cr3
    KVM: remove duplicated task_switch check
    KVM: powerpc: Fix BUILD_BUG_ON condition
    KVM: VMX: Use shared msr infrastructure
    ...

    Trivial conflicts due to new Kconfig options in arch/Kconfig and kernel/Makefile

    Linus Torvalds
     

08 Nov, 2009

1 commit

  • This patch rebase the implementation of the breakpoints API on top of
    perf events instances.

    Each breakpoints are now perf events that handle the
    register scheduling, thread/cpu attachment, etc..

    The new layering is now made as follows:

    ptrace kgdb ftrace perf syscall
    \ | / /
    \ | / /
    /
    Core breakpoint API /
    /
    | /
    | /

    Breakpoints perf events

    |
    |

    Breakpoints PMU ---- Debug Register constraints handling
    (Part of core breakpoint API)
    |
    |

    Hardware debug registers

    Reasons of this rewrite:

    - Use the centralized/optimized pmu registers scheduling,
    implying an easier arch integration
    - More powerful register handling: perf attributes (pinned/flexible
    events, exclusive/non-exclusive, tunable period, etc...)

    Impact:

    - New perf ABI: the hardware breakpoints counters
    - Ptrace breakpoints setting remains tricky and still needs some per
    thread breakpoints references.

    Todo (in the order):

    - Support breakpoints perf counter events for perf tools (ie: implement
    perf_bpcounter_event())
    - Support from perf tools

    Changes in v2:

    - Follow the perf "event " rename
    - The ptrace regression have been fixed (ptrace breakpoint perf events
    weren't released when a task ended)
    - Drop the struct hw_breakpoint and store generic fields in
    perf_event_attr.
    - Separate core and arch specific headers, drop
    asm-generic/hw_breakpoint.h and create linux/hw_breakpoint.h
    - Use new generic len/type for breakpoint
    - Handle off case: when breakpoints api is not supported by an arch

    Changes in v3:

    - Fix broken CONFIG_KVM, we need to propagate the breakpoint api
    changes to kvm when we exit the guest and restore the bp registers
    to the host.

    Changes in v4:

    - Drop the hw_breakpoint_restore() stub as it is only used by KVM
    - EXPORT_SYMBOL_GPL hw_breakpoint_restore() as KVM can be built as a
    module
    - Restore the breakpoints unconditionally on kvm guest exit:
    TIF_DEBUG_THREAD doesn't anymore cover every cases of running
    breakpoints and vcpu->arch.switch_db_regs might not always be
    set when the guest used debug registers.
    (Waiting for a reliable optimization)

    Changes in v5:

    - Split-up the asm-generic/hw-breakpoint.h moving to
    linux/hw_breakpoint.h into a separate patch
    - Optimize the breakpoints restoring while switching from kvm guest
    to host. We only want to restore the state if we have active
    breakpoints to the host, otherwise we don't care about messed-up
    address registers.
    - Add asm/hw_breakpoint.h to Kbuild
    - Fix bad breakpoint type in trace_selftest.c

    Changes in v6:

    - Fix wrong header inclusion in trace.h (triggered a build
    error with CONFIG_FTRACE_SELFTEST

    Signed-off-by: Frederic Weisbecker
    Cc: Prasad
    Cc: Alan Stern
    Cc: Peter Zijlstra
    Cc: Arnaldo Carvalho de Melo
    Cc: Steven Rostedt
    Cc: Ingo Molnar
    Cc: Jan Kiszka
    Cc: Jiri Slaby
    Cc: Li Zefan
    Cc: Avi Kivity
    Cc: Paul Mackerras
    Cc: Mike Galbraith
    Cc: Masami Hiramatsu
    Cc: Paul Mundt

    Frederic Weisbecker
     

18 Oct, 2009

1 commit


02 Oct, 2009

1 commit

  • Add a general per-cpu notifier that is called whenever the kernel is
    about to return to userspace. The notifier uses a thread_info flag
    and existing checks, so there is no impact on user return or context
    switch fast paths.

    This will be used initially to speed up KVM task switching by lazily
    updating MSRs.

    Signed-off-by: Avi Kivity
    LKML-Reference:
    Signed-off-by: H. Peter Anvin

    Avi Kivity
     

18 Sep, 2009

1 commit

  • commit 85bac32c4a52c592b857f2c360cc5ec93a097d70
    ring-buffer: only enable ring_buffer_swap_cpu when needed
    broke oprofile (at least on s390, but likely on all platforms).

    this patch lets oprofile select RING_BUFER_ALLOW_SWAP to make
    ring_buffer_swap_cpu usable for oprofile.

    Signed-off-by: Christian Borntraeger
    LKML-Reference:
    Cc: Ingo Molnar
    Cc: Robert Richter
    Signed-off-by: Steven Rostedt

    Christian Borntraeger
     

15 Sep, 2009

1 commit


07 Sep, 2009

1 commit


20 Jul, 2009

1 commit

  • The number of hardware counters is limited. The multiplexing feature
    enables OProfile to gather more events than counters are provided by
    the hardware. This is realized by switching between events at an user
    specified time interval.

    A new file (/dev/oprofile/time_slice) is added for the user to specify
    the timer interval in ms. If the number of events to profile is higher
    than the number of hardware counters available, the patch will
    schedule a work queue that switches the event counter and re-writes
    the different sets of values into it. The switching mechanism needs to
    be implemented for each architecture to support multiplexing. This
    patch only implements AMD CPU support, but multiplexing can be easily
    extended for other models and architectures.

    There are follow-on patches that rework parts of this patch.

    Signed-off-by: Jason Yeh
    Signed-off-by: Robert Richter

    Jason Yeh
     

19 Jun, 2009

1 commit

  • Enable the use of GCC's coverage testing tool gcov [1] with the Linux
    kernel. gcov may be useful for:

    * debugging (has this code been reached at all?)
    * test improvement (how do I change my test to cover these lines?)
    * minimizing kernel configurations (do I need this option if the
    associated code is never run?)

    The profiling patch incorporates the following changes:

    * change kbuild to include profiling flags
    * provide functions needed by profiling code
    * present profiling data as files in debugfs

    Note that on some architectures, enabling gcc's profiling option
    "-fprofile-arcs" for the entire kernel may trigger compile/link/
    run-time problems, some of which are caused by toolchain bugs and
    others which require adjustment of architecture code.

    For this reason profiling the entire kernel is initially restricted
    to those architectures for which it is known to work without changes.
    This restriction can be lifted once an architecture has been tested
    and found compatible with gcc's profiling. Profiling of single files
    or directories is still available on all platforms (see config help
    text).

    [1] http://gcc.gnu.org/onlinedocs/gcc/Gcov.html

    Signed-off-by: Peter Oberparleiter
    Cc: Andi Kleen
    Cc: Huang Ying
    Cc: Li Wei
    Cc: Michael Ellerman
    Cc: Ingo Molnar
    Cc: Heiko Carstens
    Cc: Martin Schwidefsky
    Cc: Rusty Russell
    Cc: WANG Cong
    Cc: Sam Ravnborg
    Cc: Jeff Dike
    Cc: Al Viro
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Peter Oberparleiter
     

03 Jun, 2009

1 commit

  • This patch introduces the generic Hardware Breakpoint interfaces for both user
    and kernel space requests.
    This core Api handles the hardware breakpoints through new helpers. It
    handles the user-space breakpoints and kernel breakpoints in front of
    arch implementation.

    One can choose kernel wide breakpoints using the following helpers
    and passing them a generic struct hw_breakpoint:

    - register_kernel_hw_breakpoint()
    - unregister_kernel_hw_breakpoint()
    - modify_kernel_hw_breakpoint()

    On the other side, you can choose per task breakpoints.

    - register_user_hw_breakpoint()
    - unregister_user_hw_breakpoint()
    - modify_user_hw_breakpoint()

    [ fweisbec@gmail.com: fix conflict against perfcounter ]

    Original-patch-by: Alan Stern
    Signed-off-by: K.Prasad
    Reviewed-by: Alan Stern
    Signed-off-by: Frederic Weisbecker

    K.Prasad
     

10 Apr, 2009

1 commit

  • Impact: performance regression fix for s390

    The adaptive spinning mutexes will not always do what one would expect on
    virtualized architectures like s390. Especially the cpu_relax() loop in
    mutex_spin_on_owner might hurt if the mutex holding cpu has been scheduled
    away by the hypervisor.

    We would end up in a cpu_relax() loop when there is no chance that the
    state of the mutex changes until the target cpu has been scheduled again by
    the hypervisor.

    For that reason we should change the default behaviour to no-spin on s390.

    We do have an instruction which allows to yield the current cpu in favour of
    a different target cpu. Also we have an instruction which allows us to figure
    out if the target cpu is physically backed.

    However we need to do some performance tests until we can come up with
    a solution that will do the right thing on s390.

    Signed-off-by: Heiko Carstens
    Acked-by: Peter Zijlstra
    Cc: Martin Schwidefsky
    Cc: Christian Borntraeger
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Heiko Carstens
     

02 Apr, 2009

1 commit


06 Mar, 2009

1 commit


05 Mar, 2009

1 commit


14 Jan, 2009

1 commit

  • From: Martin Schwidefsky

    By selecting HAVE_SYSCALL_WRAPPERS architectures can activate
    system call wrappers in order to sign extend system call arguments.

    All architectures where the ABI defines that the caller of a function
    has to perform sign extension probably need this.

    Reported-by: Christian Borntraeger
    Acked-by: Ralf Baechle
    Signed-off-by: Martin Schwidefsky
    Signed-off-by: Heiko Carstens

    Heiko Carstens
     

12 Dec, 2008

1 commit

  • Impact: build fix

    OProfile now depends on the ring buffer infrastructure:

    arch/x86/oprofile/built-in.o: In function `oprofile_add_ibs_sample':
    : undefined reference to `ring_buffer_unlock_commit'

    Select TRACING and RING_BUFFER when oprofile is enabled.

    Signed-off-by: Ingo Molnar

    Ingo Molnar
     

01 Dec, 2008

1 commit

  • All architectures now use the generic compat_sys_ptrace, as should every
    new architecture that needs 32bit compat (if we'll ever get another).

    Remove the now superflous __ARCH_WANT_COMPAT_SYS_PTRACE define, and also
    kill a comment about __ARCH_SYS_PTRACE that was added after
    __ARCH_SYS_PTRACE was already gone.

    Signed-off-by: Christoph Hellwig
    Acked-by: David S. Miller
    Signed-off-by: Linus Torvalds

    Christoph Hellwig
     

28 Oct, 2008

1 commit


17 Oct, 2008

1 commit

  • Using "def_bool n" is pointless, simply using bool here appears more
    appropriate.

    Further, retaining such options that don't have a prompt and aren't
    selected by anything seems also at least questionable.

    Signed-off-by: Jan Beulich
    Cc: Ingo Molnar
    Cc: Tony Luck
    Cc: Thomas Gleixner
    Cc: Bartlomiej Zolnierkiewicz
    Cc: Sam Ravnborg
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jan Beulich
     

13 Oct, 2008

1 commit


27 Jul, 2008

1 commit

  • This adds the generic HAVE_ARCH_TRACEHOOK kconfig item. Each arch should
    add to some Kconfig file:

    select HAVE_ARCH_TRACEHOOK

    if the arch code uses all the latest hooks to enable newfangled tracing
    and debugging code. The comment in arch/Kconfig lists all the
    prerequisite arch support. When all these are available, setting
    HAVE_ARCH_TRACEHOOK will allow enabling any new features that depend on
    the modern arch interfaces.

    Signed-off-by: Roland McGrath
    Cc: Oleg Nesterov
    Reviewed-by: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Roland McGrath
     

26 Jul, 2008

2 commits

  • Signed-off-by: Robert Richter
    Cc: oprofile-list
    Cc: Robert Richter
    Cc: Barry Kasindorf
    Signed-off-by: Ingo Molnar

    Robert Richter
     
  • In many cases, especially in networking, it can be beneficial to know at
    compile time whether the architecture can do unaligned accesses efficiently.
    This patch introduces a new Kconfig symbol

    HAVE_EFFICIENT_UNALIGNED_ACCESS

    for that purpose and adds it to the powerpc and x86 architectures. Also add
    some documentation about alignment and networking, and especially one intended
    use of this symbol.

    Signed-off-by: Johannes Berg
    Acked-by: Sam Ravnborg
    Acked-by: Ingo Molnar [x86 architecture part]
    Cc:
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Johannes Berg
     

25 Jul, 2008

2 commits

  • In order to be able to debug things like the X server and programs using
    the PPC Cell SPUs, the debugger needs to be able to access device memory
    through ptrace and /proc/pid/mem.

    This patch:

    Add the generic_access_phys access function and put the hooks in place
    to allow access_process_vm to access device or PPC Cell SPU memory.

    [riel@redhat.com: Add documentation for the vm_ops->access function]
    Signed-off-by: Rik van Riel
    Signed-off-by: Benjamin Herrensmidt
    Cc: Dave Airlie
    Cc: Hugh Dickins
    Cc: Paul Mackerras
    Cc: Arnd Bergmann
    Acked-by: Peter Zijlstra
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Rik van Riel
     
  • Flag platforms as HAVE_CLK (or not) in Kconfig, based on whether they
    support calls, so that otherwise portable drivers which need
    those calls can list that dependency.

    Something like this is a prerequisite for merging the musb_hdrc driver,
    currently used on platforms including Davinci, OMAP2430, OMAP3xx ... and
    the discrete TUSB6010 chip, which doesn't have a natural platform
    dependency. (Used with OMAP 2420 in current Nokia N8x0 tablets.)

    Signed-off-by: David Brownell
    Cc: Russell King
    Acked-by: Haavard Skinnemoen
    Cc: Benjamin Herrenschmidt
    Cc: Paul Mackerras
    Cc: Paul Mundt
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    David Brownell
     

26 Jun, 2008

1 commit

  • This adds kernel/smp.c which contains helpers for IPI function calls. In
    addition to supporting the existing smp_call_function() in a more efficient
    manner, it also adds a more scalable variant called smp_call_function_single()
    for calling a given function on a single CPU only.

    The core of this is based on the x86-64 patch from Nick Piggin, lots of
    changes since then. "Alan D. Brunelle" has
    contributed lots of fixes and suggestions as well. Also thanks to
    Paul E. McKenney for reviewing RCU usage
    and getting rid of the data allocation fallback deadlock.

    Acked-by: Ingo Molnar
    Reviewed-by: Paul E. McKenney
    Signed-off-by: Jens Axboe

    Jens Axboe
     

29 Apr, 2008

1 commit

  • Introduce new interfaces, dma_*map*_attrs(), for passing architecture-specific
    attributes when memory is mapped and unmapped for DMA. Give the interfaces
    default implementations which ignore attributes. Also introduce the
    dma_{set|get}_attr() interfaces for setting and retrieving individual
    attributes. Define one attribute, DMA_ATTR_WRITE_BARRIER, in anticipation of
    its use by ia64/sn. Select whether architectures implement arch-specific
    versions of the dma_*map*_attrs() interfaces via HAVE_DMA_ATTRS in Kconfig.

    [markn@au1.ibm.com: dma_{set,get}_attr() have to be static inline]
    Signed-off-by: Arthur Kepner
    Cc: Tony Luck
    Cc: Jesse Barnes
    Cc: Jes Sorensen
    Cc: Randy Dunlap
    Cc: Roland Dreier
    Cc: James Bottomley
    Cc: David Miller
    Cc: Benjamin Herrenschmidt
    Cc: Grant Grundler
    Cc: Michael Ellerman
    Signed-off-by: Mark Nelson
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Arthur Kepner
     

05 Mar, 2008

1 commit

  • Add CONFIG_HAVE_KRETPROBES to the arch//Kconfig file for relevant
    architectures with kprobes support. This facilitates easy handling of
    in-kernel modules (like samples/kprobes/kretprobe_example.c) that depend on
    kretprobes being present in the kernel.

    Thanks to Sam Ravnborg for helping make the patch more lean.

    Per Mathieu's suggestion, added CONFIG_KRETPROBES and fixed up dependencies.

    Signed-off-by: Ananth N Mavinakayanahalli
    Acked-by: Mathieu Desnoyers
    Acked-by: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ananth N Mavinakayanahalli
     

03 Feb, 2008

2 commits

  • Move the instrumentation Kconfig to

    arch/Kconfig for architecture dependent options
    - oprofile
    - kprobes

    and

    init/Kconfig for architecture independent options
    - profiling
    - markers

    Remove the "Instrumentation Support" menu. Everything moves to "General setup".
    Delete the kernel/Kconfig.instrumentation file.

    Signed-off-by: Mathieu Desnoyers
    Cc: Linus Torvalds
    Cc:
    Signed-off-by: Sam Ravnborg

    Mathieu Desnoyers
     
  • Puts the content of arch/Kconfig in the "General setup" menu.

    Linus:

    > Should it come with a re-duplication of it's content into each
    > architecture, which was the case previously ? The oprofile and kprobes
    > menu entries were litteraly cut and pasted from one architecture to
    > another. Should we put its content in init/Kconfig then ?

    I don't think it's a good idea to go back to making it per-architecture,
    although that extensive "depends on " might
    indicate that there certainly is room for cleanup there.

    And I don't think it's wrong keeping it in kernel/Kconfig.xyz per se, I
    just think it's wrong to (a) lump the code together when it really doesn't
    necessarily need to and (b) show it to users as some kind of choice that
    is tied together (whether it then has common code or not).

    On the per-architecture side, I do think it would be better to *not* have
    internal architecture knowledge in a generic file, and as such a line like

    depends on X86_32 || IA64 || PPC || S390 || SPARC64 || X86_64 || AVR32

    really shouldn't exist in a file like kernel/Kconfig.instrumentation.

    It would be much better to do

    depends on ARCH_SUPPORTS_KPROBES

    in that generic file, and then architectures that do support it would just
    have a

    bool ARCH_SUPPORTS_KPROBES
    default y

    in *their* architecture files. That would seem to be much more logical,
    and is readable both for arch maintainers *and* for people who have no
    clue - and don't care - about which architecture is supposed to support
    which interface...

    Sam Ravnborg:

    Stuff it into a new file: arch/Kconfig
    We can then extend this file to include all the 'trailing'
    Kconfig things that are anyway equal for all ARCHs.

    But it should be kept clean - so if we introduce such a file
    then we should use ARCH_HAS_whatever in the arch specific Kconfig
    files to enable stuff that is not shared.

    [...]

    The above suggestion is actually not exactly the best way to do it...
    First the naming..
    A quick grep shows following usage today (in Kconfig files)
    ARCH_HAS 51
    ARCH_SUPPORTS 4
    HAVE_ARCH 7

    ARCH_HAS is the clear winner.

    In the common Kconfig file do:

    config FOO
    depends on ARCH_HAS_FOO
    bool "bla bla"

    config ARCH_HAS_FOO
    def_bool n

    In the arch specific Kconfig file in a suitable place do:

    config SUITABLE_OPTION
    select ARCH_HAS_FOO

    The naming of ARCH_HAS_ is fixed and shall be:
    ARCH_HAS_

    Only a single line added pr. architecture.
    And we will end up with a (maybe even commented) list of trivial selects.

    - Yet another update :

    Moving to HAVE_* now.

    Signed-off-by: Mathieu Desnoyers
    Cc: Jeff Dike
    Cc: David Howells
    Cc: Ananth N Mavinakayanahalli
    Signed-off-by: Sam Ravnborg

    Mathieu Desnoyers