11 Sep, 2005

1 commit

  • This patch (written by me and also containing many suggestions of Arjan van
    de Ven) does a major cleanup of the spinlock code. It does the following
    things:

    - consolidates and enhances the spinlock/rwlock debugging code

    - simplifies the asm/spinlock.h files

    - encapsulates the raw spinlock type and moves generic spinlock
    features (such as ->break_lock) into the generic code.

    - cleans up the spinlock code hierarchy to get rid of the spaghetti.

    Most notably there's now only a single variant of the debugging code,
    located in lib/spinlock_debug.c. (previously we had one SMP debugging
    variant per architecture, plus a separate generic one for UP builds)

    Also, i've enhanced the rwlock debugging facility, it will now track
    write-owners. There is new spinlock-owner/CPU-tracking on SMP builds too.
    All locks have lockup detection now, which will work for both soft and hard
    spin/rwlock lockups.

    The arch-level include files now only contain the minimally necessary
    subset of the spinlock code - all the rest that can be generalized now
    lives in the generic headers:

    include/asm-i386/spinlock_types.h | 16
    include/asm-x86_64/spinlock_types.h | 16

    I have also split up the various spinlock variants into separate files,
    making it easier to see which does what. The new layout is:

    SMP | UP
    ----------------------------|-----------------------------------
    asm/spinlock_types_smp.h | linux/spinlock_types_up.h
    linux/spinlock_types.h | linux/spinlock_types.h
    asm/spinlock_smp.h | linux/spinlock_up.h
    linux/spinlock_api_smp.h | linux/spinlock_api_up.h
    linux/spinlock.h | linux/spinlock.h

    /*
    * here's the role of the various spinlock/rwlock related include files:
    *
    * on SMP builds:
    *
    * asm/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the
    * initializers
    *
    * linux/spinlock_types.h:
    * defines the generic type and initializers
    *
    * asm/spinlock.h: contains the __raw_spin_*()/etc. lowlevel
    * implementations, mostly inline assembly code
    *
    * (also included on UP-debug builds:)
    *
    * linux/spinlock_api_smp.h:
    * contains the prototypes for the _spin_*() APIs.
    *
    * linux/spinlock.h: builds the final spin_*() APIs.
    *
    * on UP builds:
    *
    * linux/spinlock_type_up.h:
    * contains the generic, simplified UP spinlock type.
    * (which is an empty structure on non-debug builds)
    *
    * linux/spinlock_types.h:
    * defines the generic type and initializers
    *
    * linux/spinlock_up.h:
    * contains the __raw_spin_*()/etc. version of UP
    * builds. (which are NOPs on non-debug, non-preempt
    * builds)
    *
    * (included on UP-non-debug builds:)
    *
    * linux/spinlock_api_up.h:
    * builds the _spin_*() APIs.
    *
    * linux/spinlock.h: builds the final spin_*() APIs.
    */

    All SMP and UP architectures are converted by this patch.

    arm, i386, ia64, ppc, ppc64, s390/s390x, x64 was build-tested via
    crosscompilers. m32r, mips, sh, sparc, have not been tested yet, but should
    be mostly fine.

    From: Grant Grundler

    Booted and lightly tested on a500-44 (64-bit, SMP kernel, dual CPU).
    Builds 32-bit SMP kernel (not booted or tested). I did not try to build
    non-SMP kernels. That should be trivial to fix up later if necessary.

    I converted bit ops atomic_hash lock to raw_spinlock_t. Doing so avoids
    some ugly nesting of linux/*.h and asm/*.h files. Those particular locks
    are well tested and contained entirely inside arch specific code. I do NOT
    expect any new issues to arise with them.

    If someone does ever need to use debug/metrics with them, then they will
    need to unravel this hairball between spinlocks, atomic ops, and bit ops
    that exist only because parisc has exactly one atomic instruction: LDCW
    (load and clear word).

    From: "Luck, Tony"

    ia64 fix

    Signed-off-by: Ingo Molnar
    Signed-off-by: Arjan van de Ven
    Signed-off-by: Grant Grundler
    Cc: Matthew Wilcox
    Signed-off-by: Hirokazu Takata
    Signed-off-by: Mikael Pettersson
    Signed-off-by: Benoit Boissinot
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ingo Molnar
     

08 Sep, 2005

1 commit

  • This patch adds a new kernel debug feature: CONFIG_DETECT_SOFTLOCKUP.

    When enabled then per-CPU watchdog threads are started, which try to run
    once per second. If they get delayed for more than 10 seconds then a
    callback from the timer interrupt detects this condition and prints out a
    warning message and a stack dump (once per lockup incident). The feature
    is otherwise non-intrusive, it doesnt try to unlock the box in any way, it
    only gets the debug info out, automatically, and on all CPUs affected by
    the lockup.

    Signed-off-by: Ingo Molnar
    Signed-off-by: Nishanth Aravamudan
    Signed-Off-By: Matthias Urlichs
    Signed-off-by: Richard Purdie
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ingo Molnar
     

26 Jun, 2005

2 commits

  • This patch provides the interfaces necessary to read the dump contents,
    treating it as a high memory device.

    Signed off by Hariprasad Nellitheertha
    Signed-off-by: Eric Biederman
    Signed-off-by: Vivek Goyal
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Vivek Goyal
     
  • This patch introduces the architecture independent implementation the
    sys_kexec_load, the compat_sys_kexec_load system calls.

    Kexec on panic support has been integrated into the core patch and is
    relatively clean.

    In addition the hopefully architecture independent option
    crashkernel=size@location has been docuemented. It's purpose is to reserve
    space for the panic kernel to live, and where no DMA transfer will ever be
    setup to access.

    Signed-off-by: Eric Biederman
    Signed-off-by: Alexander Nyberg
    Signed-off-by: Adrian Bunk
    Signed-off-by: Vivek Goyal
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Eric W. Biederman
     

06 May, 2005

1 commit

  • While looking at code generated by gcc4.0 I noticed some functions still
    had frame pointers, even after we stopped ppc64 from defining
    CONFIG_FRAME_POINTER. It turns out kernel/Makefile hardwires
    -fno-omit-frame-pointer on when compiling schedule.c.

    Create CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER and define it on architectures
    that dont require frame pointers in sched.c code.

    (akpm: blame me for the name)

    Signed-off-by: Anton Blanchard
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Anton Blanchard
     

17 Apr, 2005

1 commit

  • 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