Eric Lee / smarc-fsl-linux-kernel

13 Nov, 2012

1 commit

  • f7c83bcbf   net: xfrm: use __this_cpu_read per-cpu helper ... Browse Code »

    this_cpu_ptr/this_cpu_read is faster than per_cpu_ptr(p, smp_processor_id())
    and can reduce memory accesses.
    The latter helper needs to find the offset for current cpu,
    and needs more assembler instructions which objdump shows in following.

    this_cpu_ptr relocates and address. this_cpu_read() relocates the address
    and performs the fetch. this_cpu_read() saves you more instructions
    since it can do the relocation and the fetch in one instruction.

    per_cpu_ptr(p, smp_processor_id())：
    1e: 65 8b 04 25 00 00 00 00 mov %gs:0x0,%eax
    26: 48 98 cltq
    28: 31 f6 xor %esi,%esi
    2a: 48 c7 c7 00 00 00 00 mov $0x0,%rdi
    31: 48 8b 04 c5 00 00 00 00 mov 0x0(,%rax,8),%rax
    39: c7 44 10 04 14 00 00 00 movl $0x14,0x4(%rax,%rdx,1)

    this_cpu_ptr(p)
    1e: 65 48 03 14 25 00 00 00 00 add %gs:0x0,%rdx
    27: 31 f6 xor %esi,%esi
    29: c7 42 04 14 00 00 00 movl $0x14,0x4(%rdx)
    30: 48 c7 c7 00 00 00 00 mov $0x0,%rdi

    Signed-off-by: Shan Wei
    Signed-off-by: Steffen Klassert

    Shan Wei
     

19 Oct, 2011

1 commit

  • 9e903e085   net: add skb frag size accessors ... Browse Code »

    To ease skb->truesize sanitization, its better to be able to localize
    all references to skb frags size.

    Define accessors : skb_frag_size() to fetch frag size, and
    skb_frag_size_{set|add|sub}() to manipulate it.

    Signed-off-by: Eric Dumazet
    Signed-off-by: David S. Miller

    Eric Dumazet
     

25 Aug, 2011

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
     

17 Feb, 2010

1 commit

  • 7d720c3e4   percpu: add __percpu sparse annotations to net ... Browse Code »

    Add __percpu sparse annotations to net.

    These annotations are to make sparse consider percpu variables to be
    in a different address space and warn if accessed without going
    through percpu accessors. This patch doesn't affect normal builds.

    The macro and type tricks around snmp stats make things a bit
    interesting. DEFINE/DECLARE_SNMP_STAT() macros mark the target field
    as __percpu and SNMP_UPD_PO_STATS() macro is updated accordingly. All
    snmp_mib_*() users which used to cast the argument to (void **) are
    updated to cast it to (void __percpu **).

    Signed-off-by: Tejun Heo
    Acked-by: David S. Miller
    Cc: Patrick McHardy
    Cc: Arnaldo Carvalho de Melo
    Cc: Vlad Yasevich
    Cc: netdev@vger.kernel.org
    Signed-off-by: David S. Miller

    Tejun Heo
     

11 Jan, 2009

1 commit

  • 9498c0582   ipcomp: Remove spurious truesize increase ... Browse Code »

    When I made ipcomp use frags, I forgot to take out the original
    truesize update that was added for pskb_expand_head. As we no
    longer expand the head of skb, that update should have been removed.

    This bug is not related to the truesize warnings since we only
    made it bigger than what it should've been.

    Signed-off-by: Herbert Xu
    Signed-off-by: David S. Miller

    Herbert Xu
     

26 Jul, 2008

1 commit

  • 547b792ca   net: convert BUG_TRAP to generic WARN_ON ... Browse Code »

    Removes legacy reinvent-the-wheel type thing. The generic
    machinery integrates much better to automated debugging aids
    such as kerneloops.org (and others), and is unambiguous due to
    better naming. Non-intuively BUG_TRAP() is actually equal to
    WARN_ON() rather than BUG_ON() though some might actually be
    promoted to BUG_ON() but I left that to future.

    I could make at least one BUILD_BUG_ON conversion.

    Signed-off-by: Ilpo Järvinen
    Signed-off-by: David S. Miller

    Ilpo Järvinen
     

25 Jul, 2008

2 commits