Eric Lee / smarc-fsl-linux-kernel

21 Jan, 2011

1 commit

  • 9190b3b32   net_sched: accurate bytes/packets stats/rates ... Browse Code »

    In commit 44b8288308ac9d (net_sched: pfifo_head_drop problem), we fixed
    a problem with pfifo_head drops that incorrectly decreased
    sch->bstats.bytes and sch->bstats.packets

    Several qdiscs (CHOKe, SFQ, pfifo_head, ...) are able to drop a
    previously enqueued packet, and bstats cannot be changed, so
    bstats/rates are not accurate (over estimated)

    This patch changes the qdisc_bstats updates to be done at dequeue() time
    instead of enqueue() time. bstats counters no longer account for dropped
    frames, and rates are more correct, since enqueue() bursts dont have
    effect on dequeue() rate.

    Signed-off-by: Eric Dumazet
    Acked-by: Stephen Hemminger
    Signed-off-by: David S. Miller

    Eric Dumazet
     

11 Jan, 2011

1 commit

  • bfe0d0298   net_sched: factorize qdisc stats handling ... Browse Code »

    HTB takes into account skb is segmented in stats updates.
    Generalize this to all schedulers.

    They should use qdisc_bstats_update() helper instead of manipulating
    bstats.bytes and bstats.packets

    Add bstats_update() helper too for classes that use
    gnet_stats_basic_packed fields.

    Note : Right now, TCQ_F_CAN_BYPASS shortcurt can be taken only if no
    stab is setup on qdisc.

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

    Eric Dumazet
     

21 Oct, 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 Oct, 2009

1 commit

  • d250a5f90   pkt_sched: gen_estimator: Dont report fake rate estimators ... Browse Code »

    Jarek Poplawski a écrit :
    >
    >
    > Hmm... So you made me to do some "real" work here, and guess what?:
    > there is one serious checkpatch warning! ;-) Plus, this new parameter
    > should be added to the function description. Otherwise:
    > Signed-off-by: Jarek Poplawski
    >
    > Thanks,
    > Jarek P.
    >
    > PS: I guess full "Don't" would show we really mean it...

    Okay :) Here is the last round, before the night !

    Thanks again

    [RFC] pkt_sched: gen_estimator: Don't report fake rate estimators

    We currently send TCA_STATS_RATE_EST elements to netlink users, even if no estimator
    is running.

    # tc -s -d qdisc
    qdisc pfifo_fast 0: dev eth0 root bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
    Sent 112833764978 bytes 1495081739 pkt (dropped 0, overlimits 0 requeues 0)
    rate 0bit 0pps backlog 0b 0p requeues 0

    User has no way to tell if the "rate 0bit 0pps" is a real estimation, or a fake
    one (because no estimator is active)

    After this patch, tc command output is :
    $ tc -s -d qdisc
    qdisc pfifo_fast 0: dev eth0 root bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
    Sent 561075 bytes 1196 pkt (dropped 0, overlimits 0 requeues 0)
    backlog 0b 0p requeues 0

    We add a parameter to gnet_stats_copy_rate_est() function so that
    it can use gen_estimator_active(bstats, r), as suggested by Jarek.

    This parameter can be NULL if check is not necessary, (htb for
    example has a mandatory rate estimator)

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

    Eric Dumazet
     

18 Sep, 2009

1 commit

18 Aug, 2009

1 commit

  • c1a8f1f1c   net: restore gnet_stats_basic to previous definition ... Browse Code »

    In 5e140dfc1fe87eae27846f193086724806b33c7d "net: reorder struct Qdisc
    for better SMP performance" the definition of struct gnet_stats_basic
    changed incompatibly, as copies of this struct are shipped to
    userland via netlink.

    Restoring old behavior is not welcome, for performance reason.

    Fix is to use a private structure for kernel, and
    teach gnet_stats_copy_basic() to convert from kernel to user land,
    using legacy structure (struct gnet_stats_basic)

    Based on a report and initial patch from Michael Spang.

    Reported-by: Michael Spang
    Signed-off-by: Eric Dumazet
    Signed-off-by: David S. Miller

    Eric Dumazet
     

16 Mar, 2009

1 commit

  • 7cd0a6387   pkt_sched: Change misleading code in class delete. ... Browse Code »

    While looking for a possible reason of bugzilla report on HTB oops:
    http://bugzilla.kernel.org/show_bug.cgi?id=12858
    I found the code in htb_delete calling htb_destroy_class on zero
    refcount is very misleading: it can suggest this is a common path, and
    destroy is called under sch_tree_lock. Actually, this can never happen
    like this because before deletion cops->get() is done, and after
    delete a class is still used by tclass_notify. The class destroy is
    always called from cops->put(), so without sch_tree_lock.

    This doesn't mean much now (since 2.6.27) because all vulnerable calls
    were moved from htb_destroy_class to htb_delete, but there was a bug
    in older kernels. The same change is done for other classful scheds,
    which, it seems, didn't have similar locking problems here.

    Reported-by: m0sia
    Signed-off-by: Jarek Poplawski
    Signed-off-by: David S. Miller

    Jarek Poplawski
     

27 Feb, 2009

1 commit

26 Nov, 2008

1 commit

25 Nov, 2008

1 commit

  • 3f0947c3f   pkt_sched: sch_drr: fix drr_dequeue loop() ... Browse Code »

    Jarek Poplawski points out:

    If all child qdiscs of sch_drr are non-work-conserving (e.g. sch_tbf)
    drr_dequeue() will busy-loop waiting for skbs instead of leaving the
    job for a watchdog. Checking for list_empty() in each loop isn't
    necessary either, because this can never be true except the first time.

    Using non-work-conserving qdiscs as children of DRR makes no sense,
    simply bail out in that case.

    Reported-by: Jarek Poplawski
    Signed-off-by: Patrick McHardy
    Signed-off-by: David S. Miller

    Patrick McHardy
     

21 Nov, 2008

1 commit

20 Nov, 2008

2 commits

  • b94c8afcb   pkt_sched: remove unnecessary xchg() in packet schedulers ... Browse Code »

    The use of xchg() hasn't been necessary since 2.2.something when proper
    locking was added to packet schedulers.

    Signed-off-by: Patrick McHardy
    Signed-off-by: David S. Miller

    Patrick McHardy
     
  • 13d2a1d2b   pkt_sched: add DRR scheduler ... Browse Code »

    Add classful DRR scheduler as a more flexible replacement for SFQ.

    The main difference to the algorithm described in "Efficient Fair Queueing
    using Deficit Round Robin" is that this implementation doesn't drop packets
    from the longest queue on overrun because its classful and limits are
    handled by each individual child qdisc.

    Signed-off-by: Patrick McHardy
    Signed-off-by: David S. Miller

    Patrick McHardy