Eric Lee / smarc-fsl-linux-kernel

06 Oct, 2006

1 commit

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
     

01 Oct, 2006

1 commit

  • b2e9c7d07   [PATCH] sysrq: disable lockdep on reboot ... Browse Code »

    SysRq : Emergency Sync
    Emergency Sync complete
    SysRq : Emergency Remount R/O
    Emergency Remount complete
    SysRq : Resetting
    BUG: warning at kernel/lockdep.c:1816/trace_hardirqs_on() (Not tainted)

    Call Trace:
    [] show_trace+0xae/0x319
    [] dump_stack+0x15/0x17
    [] trace_hardirqs_on+0xbc/0x13d
    [] sysrq_handle_reboot+0x9/0x11
    [] __handle_sysrq+0x99/0x130
    [] handle_sysrq+0x17/0x19
    [] kbd_event+0x32e/0x57d
    [] input_event+0x42d/0x45b
    [] atkbd_interrupt+0x44d/0x53d
    [] serio_interrupt+0x49/0x86
    [] i8042_interrupt+0x202/0x21a
    [] handle_IRQ_event+0x2c/0x64
    [] __do_IRQ+0xaf/0x114
    [] do_IRQ+0xf8/0x107
    [] ret_from_intr+0x0/0xf
    DWARF2 unwinder stuck at ret_from_intr+0x0/0xf
    Leftover inexact backtrace:
    [] mwait_idle+0x3f/0x54
    [] cpu_idle+0xa2/0xc5
    [] rest_init+0x2b/0x2d
    [] start_kernel+0x24a/0x24c
    [] _sinittext+0x28b/0x292

    Since we're shutting down anyway, don't bother being smart,
    just turn the thing off.

    Signed-off-by: Peter Zijlstra
    Acked-by: Ingo Molnar
    Cc: Arjan van de Ven
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Peter Zijlstra
     

30 Sep, 2006

1 commit

  • f400e198b   [PATCH] pidspace: is_init() ... Browse Code »

    This is an updated version of Eric Biederman's is_init() patch.
    (http://lkml.org/lkml/2006/2/6/280). It applies cleanly to 2.6.18-rc3 and
    replaces a few more instances of ->pid == 1 with is_init().

    Further, is_init() checks pid and thus removes dependency on Eric's other
    patches for now.

    Eric's original description:

    There are a lot of places in the kernel where we test for init
    because we give it special properties. Most significantly init
    must not die. This results in code all over the kernel test
    ->pid == 1.

    Introduce is_init to capture this case.

    With multiple pid spaces for all of the cases affected we are
    looking for only the first process on the system, not some other
    process that has pid == 1.

    Signed-off-by: Eric W. Biederman
    Signed-off-by: Sukadev Bhattiprolu
    Cc: Dave Hansen
    Cc: Serge Hallyn
    Cc: Cedric Le Goater
    Cc:
    Acked-by: Paul Mackerras
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Sukadev Bhattiprolu
     

04 Jul, 2006

2 commits

  • 8c64580d5   [PATCH] lockdep: print all lock classes on SysRQ-D ... Browse Code »

    Print all lock-classes on SysRq-D.

    Signed-off-by: Ingo Molnar
    Signed-off-by: Arjan van de Ven
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ingo Molnar
     
  • 9a11b49a8   [PATCH] lockdep: better lock debugging ... Browse Code »

    Generic lock debugging:

    - generalized lock debugging framework. For example, a bug in one lock
    subsystem turns off debugging in all lock subsystems.

    - got rid of the caller address passing (__IP__/__IP_DECL__/etc.) from
    the mutex/rtmutex debugging code: it caused way too much prototype
    hackery, and lockdep will give the same information anyway.

    - ability to do silent tests

    - check lock freeing in vfree too.

    - more finegrained debugging options, to allow distributions to
    turn off more expensive debugging features.

    There's no separate 'held mutexes' list anymore - but there's a 'held locks'
    stack within lockdep, which unifies deadlock detection across all lock
    classes. (this is independent of the lockdep validation stuff - lockdep first
    checks whether we are holding a lock already)

    Here are the current debugging options:

    CONFIG_DEBUG_MUTEXES=y
    CONFIG_DEBUG_LOCK_ALLOC=y

    which do:

    config DEBUG_MUTEXES
    bool "Mutex debugging, basic checks"

    config DEBUG_LOCK_ALLOC
    bool "Detect incorrect freeing of live mutexes"

    Signed-off-by: Ingo Molnar
    Signed-off-by: Arjan van de Ven
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ingo Molnar
     

01 Jul, 2006

1 commit

26 Mar, 2006

1 commit

21 Feb, 2006

1 commit

  • 9b0f8b040   [PATCH] Terminate process that fails on a constrained allocation ... Browse Code »

    Some allocations are restricted to a limited set of nodes (due to memory
    policies or cpuset constraints). If the page allocator is not able to find
    enough memory then that does not mean that overall system memory is low.

    In particular going postal and more or less randomly shooting at processes
    is not likely going to help the situation but may just lead to suicide (the
    whole system coming down).

    It is better to signal to the process that no memory exists given the
    constraints that the process (or the configuration of the process) has
    placed on the allocation behavior. The process may be killed but then the
    sysadmin or developer can investigate the situation. The solution is
    similar to what we do when running out of hugepages.

    This patch adds a check before we kill processes. At that point
    performance considerations do not matter much so we just scan the zonelist
    and reconstruct a list of nodes. If the list of nodes does not contain all
    online nodes then this is a constrained allocation and we should kill the
    current process.

    Signed-off-by: Christoph Lameter
    Cc: Nick Piggin
    Cc: Andi Kleen
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Christoph Lameter
     

10 Jan, 2006

1 commit

09 Nov, 2005

1 commit

27 Jul, 2005

1 commit

  • 4de8b9b76   [PATCH] Update sysrq-B to use emergency_restart() ... Browse Code »

    sysrq calls into the reboot path from an interrupt handler
    we can either push the code do into process context and
    call kernel_restart and get a clean reboot or we can simply
    reboot the machine, and increase our chances of actually
    rebooting. emergency_reboot() seems like the closest match
    to what we have previously done, and what we want.

    Signed-off-by: Eric W. Biederman
    Signed-off-by: Linus Torvalds

    Eric W. Biederman
     

08 Jul, 2005

1 commit

26 Jun, 2005

2 commits

  • 6e274d144   [PATCH] kdump: Use real pt_regs from exception ... Browse Code »

    Makes kexec_crashdump() take a pt_regs * as an argument. This allows to
    get exact register state at the point of the crash. If we come from direct
    panic assertion NULL will be passed and the current registers saved before
    crashdump.

    This hooks into two places:
    die(): check the conditions under which we will panic when calling
    do_exit and go there directly with the pt_regs that caused the fatal
    fault.

    die_nmi(): If we receive an NMI lockup while in the kernel use the
    pt_regs and go directly to crash_kexec(). We're probably nested up badly
    at this point so this might be the only chance to escape with proper
    information.

    Signed-off-by: Alexander Nyberg
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Alexander Nyberg
     
  • 86b1ae38c   [PATCH] kdump: sysrq trigger mechanism for kexec based crashdumps ... Browse Code »

    Add a sysrq-trigger mechanism for kexec based crashdumps. Alt-Sysrq-c
    triggers a kexec based crashdump.

    Signed-off-by: Hariprasad Nellitheertha
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Hariprasad Nellitheertha
     

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