Eric Lee / smarc-fsl-linux-kernel

04 Jan, 2012

2 commits

02 Nov, 2011

2 commits

25 Mar, 2011

1 commit

  • f283c86af   fs: remove inode_lock from iput_final and prune_icache ... Browse Code »

    Now that inode state changes are protected by the inode->i_lock and
    the inode LRU manipulations by the inode_lru_lock, we can remove the
    inode_lock from prune_icache and the initial part of iput_final().

    instead of using the inode_lock to protect the inode during
    iput_final, use the inode->i_lock instead. This protects the inode
    against new references being taken while we change the inode state
    to I_FREEING, as well as preventing prune_icache from grabbing the
    inode while we are manipulating it. Hence we no longer need the
    inode_lock in iput_final prior to setting I_FREEING on the inode.

    For prune_icache, we no longer need the inode_lock to protect the
    LRU list, and the inodes themselves are protected against freeing
    races by the inode->i_lock. Hence we can lift the inode_lock from
    prune_icache as well.

    Signed-off-by: Dave Chinner
    Signed-off-by: Al Viro

    Dave Chinner
     

07 Jan, 2011

1 commit

  • fa0d7e3de   fs: icache RCU free inodes ... Browse Code »

    RCU free the struct inode. This will allow:

    - Subsequent store-free path walking patch. The inode must be consulted for
    permissions when walking, so an RCU inode reference is a must.
    - sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
    to take i_lock no longer need to take sb_inode_list_lock to walk the list in
    the first place. This will simplify and optimize locking.
    - Could remove some nested trylock loops in dcache code
    - Could potentially simplify things a bit in VM land. Do not need to take the
    page lock to follow page->mapping.

    The downsides of this is the performance cost of using RCU. In a simple
    creat/unlink microbenchmark, performance drops by about 10% due to inability to
    reuse cache-hot slab objects. As iterations increase and RCU freeing starts
    kicking over, this increases to about 20%.

    In cases where inode lifetimes are longer (ie. many inodes may be allocated
    during the average life span of a single inode), a lot of this cache reuse is
    not applicable, so the regression caused by this patch is smaller.

    The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
    however this adds some complexity to list walking and store-free path walking,
    so I prefer to implement this at a later date, if it is shown to be a win in
    real situations. I haven't found a regression in any non-micro benchmark so I
    doubt it will be a problem.

    Signed-off-by: Nick Piggin

    Nick Piggin
     

10 Aug, 2010

3 commits

22 May, 2010

1 commit

06 May, 2010

1 commit

05 May, 2010

1 commit

02 May, 2010

1 commit

30 Mar, 2010

1 commit

  • 5a0e3ad6a   include cleanup: Update gfp.h and slab.h includes to prepare for breaking implic… ... Browse Code »

    …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
     

07 Mar, 2010

1 commit

  • 66b89159c   Merge git://git.kernel.org/pub/scm/linux/kernel/git/joern/logfs ... Browse Code »

    * git://git.kernel.org/pub/scm/linux/kernel/git/joern/logfs:
    [LogFS] Change magic number
    [LogFS] Remove h_version field
    [LogFS] Check feature flags
    [LogFS] Only write journal if dirty
    [LogFS] Fix bdev erases
    [LogFS] Silence gcc
    [LogFS] Prevent 64bit divisions in hash_index
    [LogFS] Plug memory leak on error paths
    [LogFS] Add MAINTAINERS entry
    [LogFS] add new flash file system

    Fixed up trivial conflict in lib/Kconfig, and a semantic conflict in
    fs/logfs/inode.c introduced by write_inode() being changed to use
    writeback_control' by commit a9185b41a4f84971b930c519f0c63bd450c4810d
    ("pass writeback_control to ->write_inode")

    Linus Torvalds
     

21 Nov, 2009

1 commit