Eric Lee / smarc-fsl-linux-kernel

23 Oct, 2008

1 commit

17 Oct, 2008

1 commit

  • 22b8ce947   profiling: dynamically enable readprofile at runtime ... Browse Code »

    Way too often, I have a machine that exhibits some kind of crappy
    behavior. The CPU looks wedged in the kernel or it is spending way too
    much system time and I wonder what is responsible.

    I try to run readprofile. But, of course, Ubuntu doesn't enable it by
    default. Dang!

    The reason we boot-time enable it is that it takes a big bufffer that we
    generally can only bootmem alloc. But, does it hurt to at least try and
    runtime-alloc it?

    To use:
    echo 2 > /sys/kernel/profile

    Then run readprofile like normal.

    This should fix the compile issue with allmodconfig. I've compile-tested
    on a bunch more configs now including a few more architectures.

    Signed-off-by: Dave Hansen
    Acked-by: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Dave Hansen
     

26 Jul, 2008

2 commits

  • cebbd3fb8   build-kernel-profileo-only-when-requested-cleanups ... Browse Code »

    Cc: Adrian Bunk
    Cc: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Andrew Morton
     
  • b03f6489f   build kernel/profile.o only when requested ... Browse Code »

    Build kernel/profile.o only if CONFIG_PROFILING is enabled.

    This makes CONFIG_PROFILING=n kernels smaller.

    As a bonus, some profile_tick() calls and one branch from schedule() are
    now eliminated with CONFIG_PROFILING=n (but I doubt these are
    measurable effects).

    This patch changes the effects of CONFIG_PROFILING=n, but I don't think
    having more than two choices would be the better choice.

    This patch also adds the name of the first parameter to the prototypes
    of profile_{hits,tick}() since I anyway had to add them for the dummy
    functions.

    Signed-off-by: Adrian Bunk
    Cc: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Adrian Bunk
     

30 Apr, 2008

1 commit

17 Oct, 2007

1 commit

12 Jan, 2007

1 commit

  • 07031e14c   [PATCH] KVM: add VM-exit profiling ... Browse Code »

    This adds the profile=kvm boot option, which enables KVM to profile VM
    exits.

    Use: "readprofile -m ./System.map | sort -n" to see the resulting
    output:

    [...]
    18246 serial_out 148.3415
    18945 native_flush_tlb 378.9000
    23618 serial_in 212.7748
    29279 __spin_unlock_irq 622.9574
    43447 native_apic_write 2068.9048
    52702 enable_8259A_irq 742.2817
    54250 vgacon_scroll 89.3740
    67394 ide_inb 6126.7273
    79514 copy_page_range 98.1654
    84868 do_wp_page 86.6000
    140266 pit_read 783.6089
    151436 ide_outb 25239.3333
    152668 native_io_delay 21809.7143
    174783 mask_and_ack_8259A 783.7803
    362404 native_set_pte_at 36240.4000
    1688747 total 0.5009

    Signed-off-by: Ingo Molnar
    Acked-by: Avi Kivity
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ingo Molnar
     

08 Dec, 2006

1 commit

  • ece8a684c   [PATCH] sleep profiling ... Browse Code »

    Implement prof=sleep profiling. TASK_UNINTERRUPTIBLE sleeps will be taken
    as a profile hit, and every millisecond spent sleeping causes a profile-hit
    for the call site that initiated the sleep.

    Sample readprofile output on i386:

    306 ps2_sendbyte 1.3973
    432 call_usermodehelper_keys 1.9548
    484 ps2_command 0.6453
    790 __driver_attach 4.7879
    1593 msleep 44.2500
    3976 sync_buffer 64.1290
    4076 do_lookup 12.4648
    8587 sync_page 122.6714
    20820 total 0.0067

    (NOTE: architectures need to check whether get_wchan() can be called from
    deep within the wakeup path.)

    akpm: we need to mark more functions __sched. lock_sock(), msleep(), others..

    akpm: the contention in do_lookup() is a surprise. Presumably doing disk
    reads for directory contents while holding i_mutex.

    [akpm@osdl.org: various fixes]
    Signed-off-by: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ingo Molnar
     

05 Oct, 2006

1 commit

  • 7d12e780e   IRQ: Maintain regs pointer globally rather than passing to IRQ handlers ... Browse Code »

    Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
    of passing regs around manually through all ~1800 interrupt handlers in the
    Linux kernel.

    The regs pointer is used in few places, but it potentially costs both stack
    space and code to pass it around. On the FRV arch, removing the regs parameter
    from all the genirq function results in a 20% speed up of the IRQ exit path
    (ie: from leaving timer_interrupt() to leaving do_IRQ()).

    Where appropriate, an arch may override the generic storage facility and do
    something different with the variable. On FRV, for instance, the address is
    maintained in GR28 at all times inside the kernel as part of general exception
    handling.

    Having looked over the code, it appears that the parameter may be handed down
    through up to twenty or so layers of functions. Consider a USB character
    device attached to a USB hub, attached to a USB controller that posts its
    interrupts through a cascaded auxiliary interrupt controller. A character
    device driver may want to pass regs to the sysrq handler through the input
    layer which adds another few layers of parameter passing.

    I've build this code with allyesconfig for x86_64 and i386. I've runtested the
    main part of the code on FRV and i386, though I can't test most of the drivers.
    I've also done partial conversion for powerpc and MIPS - these at least compile
    with minimal configurations.

    This will affect all archs. Mostly the changes should be relatively easy.
    Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

    struct pt_regs *old_regs = set_irq_regs(regs);

    And put the old one back at the end:

    set_irq_regs(old_regs);

    Don't pass regs through to generic_handle_irq() or __do_IRQ().

    In timer_interrupt(), this sort of change will be necessary:

    - update_process_times(user_mode(regs));
    - profile_tick(CPU_PROFILING, regs);
    + update_process_times(user_mode(get_irq_regs()));
    + profile_tick(CPU_PROFILING);

    I'd like to move update_process_times()'s use of get_irq_regs() into itself,
    except that i386, alone of the archs, uses something other than user_mode().

    Some notes on the interrupt handling in the drivers:

    (*) input_dev() is now gone entirely. The regs pointer is no longer stored in
    the input_dev struct.

    (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does
    something different depending on whether it's been supplied with a regs
    pointer or not.

    (*) Various IRQ handler function pointers have been moved to type
    irq_handler_t.

    Signed-Off-By: David Howells
    (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

    David Howells
     

26 Apr, 2006

1 commit

23 Mar, 2006

1 commit

17 Apr, 2005

1 commit

  • 1da177e4c   Linux-2.6.12-rc2 ... Browse Code »

    Initial git repository build. I'm not bothering with the full history,
    even though we have it. We can create a separate "historical" git
    archive of that later if we want to, and in the meantime it's about
    3.2GB when imported into git - space that would just make the early
    git days unnecessarily complicated, when we don't have a lot of good
    infrastructure for it.

    Let it rip!

    Linus Torvalds