01 Nov, 2011

1 commit


15 Jul, 2011

2 commits


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
     

21 Jun, 2009

1 commit


18 Jun, 2009

2 commits

  • The 'rq_received' member of 'struct rpc_rqst' is used to track when we
    have received a reply to our request. With v4.1, the backchannel
    can now accept callback requests over the existing connection. Rename
    this field to make it clear that it is only used for tracking reply bytes
    and not all bytes received on the connection.

    Signed-off-by: Ricardo Labiaga
    Signed-off-by: Benny Halevy

    Ricardo Labiaga
     
  • This patch introduces support to setup the callback xprt on the client side.
    It allocates/ destroys the preallocated memory structures used to process
    backchannel requests.

    At setup time, xprt_setup_backchannel() is invoked to allocate one or
    more rpc_rqst structures and substructures. This ensures that they
    are available when an RPC callback arrives. The rpc_rqst structures
    are maintained in a linked list attached to the rpc_xprt structure.
    We keep track of the number of allocations so that they can be correctly
    removed when the channel is destroyed.

    When an RPC callback arrives, xprt_alloc_bc_request() is invoked to
    obtain a preallocated rpc_rqst structure. An rpc_xprt structure is
    returned, and its RPC_BC_PREALLOC_IN_USE bit is set in
    rpc_xprt->bc_flags. The structure is removed from the the list
    since it is now in use, and it will be later added back when its
    user is done with it.

    After the RPC callback replies, the rpc_rqst structure is returned
    by invoking xprt_free_bc_request(). This clears the
    RPC_BC_PREALLOC_IN_USE bit and adds it back to the list, allowing it
    to be reused by a subsequent RPC callback request.

    To be consistent with the reception of RPC messages, the backchannel requests
    should be placed into the 'struct rpc_rqst' rq_rcv_buf, which is then in turn
    copied to the 'struct rpc_rqst' rq_private_buf.

    [nfs41: Preallocate rpc_rqst receive buffer for handling callbacks]
    Signed-off-by: Ricardo Labiaga
    Signed-off-by: Benny Halevy
    [Update copyright notice and explain page allocation]
    Signed-off-by: Ricardo Labiaga
    Signed-off-by: Benny Halevy

    Ricardo Labiaga