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
     

16 Mar, 2010

1 commit


19 Nov, 2009

1 commit


04 Nov, 2009

1 commit


15 Oct, 2009

1 commit


12 Sep, 2009

1 commit


25 Jun, 2009

1 commit


25 Feb, 2009

1 commit

  • This patch changes the return value of nlmsg_notify() as follows:

    If NETLINK_BROADCAST_ERROR is set by any of the listeners and
    an error in the delivery happened, return the broadcast error;
    else if there are no listeners apart from the socket that
    requested a change with the echo flag, return the result of the
    unicast notification. Thus, with this patch, the unicast
    notification is handled in the same way of a broadcast listener
    that has set the NETLINK_BROADCAST_ERROR socket flag.

    This patch is useful in case that the caller of nlmsg_notify()
    wants to know the result of the delivery of a netlink notification
    (including the broadcast delivery) and take any action in case
    that the delivery failed. For example, ctnetlink can drop packets
    if the event delivery failed to provide reliable logging and
    state-synchronization at the cost of dropping packets.

    This patch also modifies the rtnetlink code to ignore the return
    value of rtnl_notify() in all callers. The function rtnl_notify()
    (before this patch) returned the error of the unicast notification
    which makes rtnl_set_sk_err() reports errors to all listeners. This
    is not of any help since the origin of the change (the socket that
    requested the echoing) notices the ENOBUFS error if the notification
    fails and should resync itself.

    Signed-off-by: Pablo Neira Ayuso
    Acked-by: Patrick McHardy
    Signed-off-by: David S. Miller

    Pablo Neira Ayuso
     

27 Jan, 2009

2 commits


04 Dec, 2008

1 commit


30 Sep, 2008

1 commit


23 Sep, 2008

1 commit