04 Jan, 2012

1 commit


04 Aug, 2011

1 commit

  • init_fault_attr_dentries() is used to export fault_attr via debugfs.
    But it can only export it in debugfs root directory.

    Per Forlin is working on mmc_fail_request which adds support to inject
    data errors after a completed host transfer in MMC subsystem.

    The fault_attr for mmc_fail_request should be defined per mmc host and
    export it in debugfs directory per mmc host like
    /sys/kernel/debug/mmc0/mmc_fail_request.

    init_fault_attr_dentries() doesn't help for mmc_fail_request. So this
    introduces fault_create_debugfs_attr() which is able to create a
    directory in the arbitrary directory and replace
    init_fault_attr_dentries().

    [akpm@linux-foundation.org: extraneous semicolon, per Randy]
    Signed-off-by: Akinobu Mita
    Tested-by: Per Forlin
    Cc: Jens Axboe
    Cc: Christoph Lameter
    Cc: Pekka Enberg
    Cc: Matt Mackall
    Cc: Randy Dunlap
    Cc: Stephen Rothwell
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     

27 Jul, 2011

2 commits

  • Now cleanup_fault_attr_dentries() recursively removes a directory, So we
    can simplify the error handling in the initialization code and no need
    to hold dentry structs for each debugfs file.

    Signed-off-by: Akinobu Mita
    Cc: Christoph Lameter
    Cc: Pekka Enberg
    Cc: Matt Mackall
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     
  • Use debugfs_remove_recursive() to simplify initialization and
    deinitialization of fault injection debugfs files.

    Signed-off-by: Akinobu Mita
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     

30 Mar, 2010

1 commit

  • …it slab.h inclusion from percpu.h

    percpu.h is included by sched.h and module.h and thus ends up being
    included when building most .c files. percpu.h includes slab.h which
    in turn includes gfp.h making everything defined by the two files
    universally available and complicating inclusion dependencies.

    percpu.h -> slab.h dependency is about to be removed. Prepare for
    this change by updating users of gfp and slab facilities include those
    headers directly instead of assuming availability. As this conversion
    needs to touch large number of source files, the following script is
    used as the basis of conversion.

    http://userweb.kernel.org/~tj/misc/slabh-sweep.py

    The script does the followings.

    * Scan files for gfp and slab usages and update includes such that
    only the necessary includes are there. ie. if only gfp is used,
    gfp.h, if slab is used, slab.h.

    * When the script inserts a new include, it looks at the include
    blocks and try to put the new include such that its order conforms
    to its surrounding. It's put in the include block which contains
    core kernel includes, in the same order that the rest are ordered -
    alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
    doesn't seem to be any matching order.

    * If the script can't find a place to put a new include (mostly
    because the file doesn't have fitting include block), it prints out
    an error message indicating which .h file needs to be added to the
    file.

    The conversion was done in the following steps.

    1. The initial automatic conversion of all .c files updated slightly
    over 4000 files, deleting around 700 includes and adding ~480 gfp.h
    and ~3000 slab.h inclusions. The script emitted errors for ~400
    files.

    2. Each error was manually checked. Some didn't need the inclusion,
    some needed manual addition while adding it to implementation .h or
    embedding .c file was more appropriate for others. This step added
    inclusions to around 150 files.

    3. The script was run again and the output was compared to the edits
    from #2 to make sure no file was left behind.

    4. Several build tests were done and a couple of problems were fixed.
    e.g. lib/decompress_*.c used malloc/free() wrappers around slab
    APIs requiring slab.h to be added manually.

    5. The script was run on all .h files but without automatically
    editing them as sprinkling gfp.h and slab.h inclusions around .h
    files could easily lead to inclusion dependency hell. Most gfp.h
    inclusion directives were ignored as stuff from gfp.h was usually
    wildly available and often used in preprocessor macros. Each
    slab.h inclusion directive was examined and added manually as
    necessary.

    6. percpu.h was updated not to include slab.h.

    7. Build test were done on the following configurations and failures
    were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
    distributed build env didn't work with gcov compiles) and a few
    more options had to be turned off depending on archs to make things
    build (like ipr on powerpc/64 which failed due to missing writeq).

    * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
    * powerpc and powerpc64 SMP allmodconfig
    * sparc and sparc64 SMP allmodconfig
    * ia64 SMP allmodconfig
    * s390 SMP allmodconfig
    * alpha SMP allmodconfig
    * um on x86_64 SMP allmodconfig

    8. percpu.h modifications were reverted so that it could be applied as
    a separate patch and serve as bisection point.

    Given the fact that I had only a couple of failures from tests on step
    6, I'm fairly confident about the coverage of this conversion patch.
    If there is a breakage, it's likely to be something in one of the arch
    headers which should be easily discoverable easily on most builds of
    the specific arch.

    Signed-off-by: Tejun Heo <tj@kernel.org>
    Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

    Tejun Heo
     

27 Feb, 2010

1 commit

  • This patch allow to inject faults only for specific slabs.
    In order to preserve default behavior cache filter is off by
    default (all caches are faulty).

    One may define specific set of slabs like this:
    # mark skbuff_head_cache as faulty
    echo 1 > /sys/kernel/slab/skbuff_head_cache/failslab
    # Turn on cache filter (off by default)
    echo 1 > /sys/kernel/debug/failslab/cache-filter
    # Turn on fault injection
    echo 1 > /sys/kernel/debug/failslab/times
    echo 1 > /sys/kernel/debug/failslab/probability

    Acked-by: David Rientjes
    Acked-by: Akinobu Mita
    Acked-by: Christoph Lameter
    Signed-off-by: Dmitry Monakhov
    Signed-off-by: Pekka Enberg

    Dmitry Monakhov
     

03 Apr, 2009

1 commit

  • Impact: cleanup

    mm/failslab.c depends on slab.h without including it:

    CC mm/failslab.o
    mm/failslab.c: In function ‘should_failslab’:
    mm/failslab.c:16: error: ‘__GFP_NOFAIL’ undeclared (first use in this function)
    mm/failslab.c:16: error: (Each undeclared identifier is reported only once
    mm/failslab.c:16: error: for each function it appears in.)
    mm/failslab.c:19: error: ‘__GFP_WAIT’ undeclared (first use in this function)
    make[1]: *** [mm/failslab.o] Error 1
    make: *** [mm] Error 2

    It gets included implicitly currently - but this will not be the
    case with upcoming kmemtrace changes.

    Signed-off-by: Pekka Enberg
    Cc: Eduard - Gabriel Munteanu
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Pekka Enberg
     

29 Dec, 2008

1 commit

  • Currently fault-injection capability for SLAB allocator is only
    available to SLAB. This patch makes it available to SLUB, too.

    [penberg@cs.helsinki.fi: unify slab and slub implementations]
    Cc: Christoph Lameter
    Cc: Matt Mackall
    Signed-off-by: Akinobu Mita
    Signed-off-by: Pekka Enberg

    Akinobu Mita