1. 09 Jul, 2008 4 commits
  2. 08 Jul, 2008 6 commits
  3. 27 Jun, 2008 1 commit
  4. 02 May, 2008 1 commit
  5. 28 Mar, 2008 1 commit
  6. 28 Jan, 2008 5 commits
  7. 13 Nov, 2007 1 commit
    • Peter P Waskiewicz Jr's avatar
      [PKT_SCHED]: Check subqueue status before calling hard_start_xmit · 5f1a485d
      Peter P Waskiewicz Jr authored
      The only qdiscs that check subqueue state before dequeue'ing are PRIO
      and RR.  The other qdiscs, including the default pfifo_fast qdisc,
      will allow traffic bound for subqueue 0 through to hard_start_xmit.
      The check for netif_queue_stopped() is done above in pkt_sched.h, so
      it is unnecessary for qdisc_restart().  However, if the underlying
      driver is multiqueue capable, and only sets queue states on subqueues,
      this will allow packets to enter the driver when it's currently unable
      to process packets, resulting in expensive requeues and driver
      entries.  This patch re-adds the check for the subqueue status before
      calling hard_start_xmit, so we can try and avoid the driver entry when
      the queues are stopped.
      Signed-off-by: default avatarPeter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      5f1a485d
  8. 18 Oct, 2007 2 commits
    • Herbert Xu's avatar
      [NET]: Fix possible dev_deactivate race condition · ce0e32e6
      Herbert Xu authored
      The function dev_deactivate is supposed to only return when
      all outstanding transmissions have completed.  Unfortunately
      it is possible for store operations in the driver's transmit
      function to only become visible after dev_deactivate returns.
      
      This patch fixes this by taking the queue lock after we see
      the end of the queue run.  This ensures that all effects of
      any previous transmit calls are visible.
      
      If however we detect that there is another queue run occuring,
      then we'll warn about it because this should never happen as
      we have pointed dev->qdisc to noop_qdisc within the same queue
      lock earlier in the functino.
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      ce0e32e6
    • Jeff Garzik's avatar
      [NET]: fix carrier-on bug? · bfaae0f0
      Jeff Garzik authored
      While looking at a net driver with the following construct,
      
      	if (!netif_carrier_ok(dev))
      		netif_carrier_on(dev);
      
      it stuck me that the netif_carrier_ok() check was redundant, since
      netif_carrier_on() checks bit __LINK_STATE_NOCARRIER anyway.  This is
      the same reason why netif_queue_stopped() need not be called prior to
      netif_wake_queue().
      
      This is true, but there is however an unwanted side effect from assuming
      that netif_carrier_on() can be called multiple times:  it touches the
      watchdog, regardless of pre-existing carrier state.
      
      The fix:  move watchdog-up inside the bit-cleared code path.
      Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      bfaae0f0
  9. 10 Oct, 2007 2 commits
    • Jamal Hadi Salim's avatar
      [NET_SCHED]: explict hold dev tx lock · 8236632f
      Jamal Hadi Salim authored
      For N cpus, with full throttle traffic on all N CPUs, funneling traffic
      to the same ethernet device, the devices queue lock is contended by all
      N CPUs constantly. The TX lock is only contended by a max of 2 CPUS.
      In the current mode of operation, after all the work of entering the
      dequeue region, we may endup aborting the path if we are unable to get
      the tx lock and go back to contend for the queue lock. As N goes up,
      this gets worse.
      
      The changes in this patch result in a small increase in performance
      with a 4CPU (2xdual-core) with no irq binding. Both e1000 and tg3
      showed similar behavior;
      Signed-off-by: default avatarJamal Hadi Salim <hadi@cyberus.ca>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      8236632f
    • Stephen Hemminger's avatar
      [NET]: Make NAPI polling independent of struct net_device objects. · bea3348e
      Stephen Hemminger authored
      Several devices have multiple independant RX queues per net
      device, and some have a single interrupt doorbell for several
      queues.
      
      In either case, it's easier to support layouts like that if the
      structure representing the poll is independant from the net
      device itself.
      
      The signature of the ->poll() call back goes from:
      
      	int foo_poll(struct net_device *dev, int *budget)
      
      to
      
      	int foo_poll(struct napi_struct *napi, int budget)
      
      The caller is returned the number of RX packets processed (or
      the number of "NAPI credits" consumed if you want to get
      abstract).  The callee no longer messes around bumping
      dev->quota, *budget, etc. because that is all handled in the
      caller upon return.
      
      The napi_struct is to be embedded in the device driver private data
      structures.
      
      Furthermore, it is the driver's responsibility to disable all NAPI
      instances in it's ->stop() device close handler.  Since the
      napi_struct is privatized into the driver's private data structures,
      only the driver knows how to get at all of the napi_struct instances
      it may have per-device.
      
      With lots of help and suggestions from Rusty Russell, Roland Dreier,
      Michael Chan, Jeff Garzik, and Jamal Hadi Salim.
      
      Bug fixes from Thomas Graf, Roland Dreier, Peter Zijlstra,
      Joseph Fannin, Scott Wood, Hans J. Koch, and Michael Chan.
      
      [ Ported to current tree and all drivers converted.  Integrated
        Stephen's follow-on kerneldoc additions, and restored poll_list
        handling to the old style to fix mutual exclusion issues.  -DaveM ]
      Signed-off-by: default avatarStephen Hemminger <shemminger@linux-foundation.org>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      bea3348e
  10. 10 Jul, 2007 5 commits
    • Patrick McHardy's avatar
      0ba48053
    • Patrick McHardy's avatar
      [NET_SCHED]: Remove CONFIG_NET_ESTIMATOR option · 876d48aa
      Patrick McHardy authored
      The generic estimator is always built in anways and all the config options
      does is prevent including a minimal amount of code for setting it up.
      Additionally the option is already automatically selected for most cases.
      Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      876d48aa
    • Krishna Kumar's avatar
      [NET]: qdisc_restart - couple of optimizations. · e50c41b5
      Krishna Kumar authored
      Changes :
      
      - netif_queue_stopped need not be called inside qdisc_restart as
        it has been called already in qdisc_run() before the first skb
        is sent, and in __qdisc_run() after each intermediate skb is
        sent (note : we are the only sender, so the queue cannot get
        stopped while the tx lock was got in the ~LLTX case).
      
      - BUG_ON((int) q->q.qlen < 0) was a relic from old times when -1
        meant more packets are available, and __qdisc_run used to loop
        when qdisc_restart() returned -1. During those days, it was
        necessary to make sure that qlen is never less than zero, since
        __qdisc_run would get into an infinite loop if no packets are on
        the queue and this bug in qdisc was there (and worse - no more
        skbs could ever get queue'd as we hold the queue lock too). With
        Herbert's recent change to return values, this check is not
        required.  Hopefully Herbert can validate this change. If at all
        this is required, it should be added to skb_dequeue (in failure
        case), and not to qdisc_qlen.
      Signed-off-by: default avatarKrishna Kumar <krkumar2@in.ibm.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      e50c41b5
    • Krishna Kumar's avatar
      [NET]: qdisc_restart - readability changes plus one bug fix. · 6c1361a6
      Krishna Kumar authored
      New changes :
      
      - Incorporated Peter Waskiewicz's comments.
      - Re-added back one warning message (on driver returning wrong value).
      
      Previous changes :
      
      - Converted to use switch/case code which looks neater.
      
      - "if (ret == NETDEV_TX_LOCKED && lockless)" is buggy, and the lockless
        check should be removed, since driver will return NETDEV_TX_LOCKED only
        if lockless is true and driver has to do the locking. In the original
        code as well as the latest code, this code can result in a bug where
        if LLTX is not set for a driver (lockless == 0) but the driver is written
        wrongly to do a trylock (despite LLTX being set), the driver returns
        LOCKED. But since lockless is zero, the packet is requeue'd instead of
        calling collision code which will issue warning and free up the skb.
        Instead this skb will be retried with this driver next time, and the same
        result will ensue. Removing this check will catch these driver bugs instead
        of hiding the problem. I am keeping this change to readability section
        since :
        	a. it is confusing to check two things as it is; and
        	b. it is difficult to keep this check in the changed 'switch' code.
      
      - Changed some names, like try_get_tx_pkt to dev_dequeue_skb (as that is
        the work being done and easier to understand) and do_dev_requeue to
        dev_requeue_skb, merged handle_dev_cpu_collision and tx_islocked to
        dev_handle_collision (handle_dev_cpu_collision is a small routine with only
        one caller, so there is no need to have two separate routines which also
        results in getting rid of two macros, etc.
      
      - Removed an XXX comment as it should never fail (I suspect this was related
        to batch skb WIP, Jamal ?). Converted some functions to original coding
        style of having the return values and the function name on same line, eg
        prio2list.
      Signed-off-by: default avatarKrishna Kumar <krkumar2@in.ibm.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      6c1361a6
    • Jamal Hadi Salim's avatar
      [NET_SCHED]: Cleanup readability of qdisc restart · c716a81a
      Jamal Hadi Salim authored
      Over the years this code has gotten hairier. Resulting in many long
      discussions over long summer days and patches that get it wrong.
      This patch helps tame that code so normal people will understand it.
      
      Thanks to Thomas Graf, Peter J. waskiewicz Jr, and Patrick McHardy
      for their valuable reviews.
      Signed-off-by: default avatarJamal Hadi Salim <hadi@cyberus.ca>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      c716a81a
  11. 03 Jun, 2007 1 commit
  12. 24 May, 2007 1 commit
  13. 11 May, 2007 4 commits
    • Herbert Xu's avatar
      [NET_SCHED]: Avoid requeue warning on dev_deactivate · 41a23b07
      Herbert Xu authored
      When we relinquish queue_lock in qdisc_restart and then retake it for
      requeueing, we might race against dev_deactivate and end up requeueing
      onto noop_qdisc.  This causes a warning to be printed.
      
      This patch fixes this by checking this before we requeue.  As an added
      bonus, we can remove the same check in __qdisc_run which was added to
      prevent dev->gso_skb from being requeued when we're shutting down.
      
      Even though we've had to add a new conditional in its place, it's better
      because it only happens on requeues rather than every single time that
      qdisc_run is called.
      
      For this to work we also need to move the clearing of gso_skb up in
      dev_deactivate as now qdisc_restart can occur even after we wait for
      __LINK_STATE_QDISC_RUNNING to clear (but it won't do anything as long
      as the queue and gso_skb is already clear).
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      41a23b07
    • Herbert Xu's avatar
      [NET_SCHED]: Reread dev->qdisc for NETDEV_TX_OK · cce1fa36
      Herbert Xu authored
      Now that we return the queue length after NETDEV_TX_OK we better
      make sure that we have the right queue.  Otherwise we can cause a
      stall after a really quick dev_deactive/dev_activate.
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      cce1fa36
    • Herbert Xu's avatar
      [NET_SCHED]: Rationalise return value of qdisc_restart · d90df3ad
      Herbert Xu authored
      The current return value scheme and associated comment was invented
      back in the 20th century when we still had that tbusy flag.  Things
      have changed quite a bit since then (even Tony Blair is moving on
      now, not to mention the new French president).
      
      All we need to indicate now is whether the caller should continue
      processing the queue.  Therefore it's sufficient if we return 0 if
      we want to stop and non-zero otherwise.
      
      This is based on a patch by Krishna Kumar.
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      d90df3ad
    • Thomas Graf's avatar
      [NET]: Fix dev->qdisc race for NETDEV_TX_LOCKED case · 5830725f
      Thomas Graf authored
      When transmit fails with NETDEV_TX_LOCKED the skb is requeued
      to dev->qdisc again. The dev->qdisc pointer is protected by
      the queue lock which needs to be dropped when attempting to
      transmit and acquired again before requeing. The problem is
      that qdisc_restart() fetches the dev->qdisc pointer once and
      stores it in the `q' variable which is invalidated when
      dropping the queue_lock, therefore the variable needs to be
      refreshed before requeueing.
      Signed-off-by: default avatarThomas Graf <tgraf@suug.ch>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      5830725f
  14. 25 Apr, 2007 2 commits
  15. 11 Feb, 2007 1 commit
  16. 08 Feb, 2007 1 commit
    • Arjan van de Ven's avatar
      [NET]: user of the jiffies rounding code: Networking · f5a6e01c
      Arjan van de Ven authored
      This patch introduces users of the round_jiffies() function in the
      networking code.
      
      These timers all were of the "about once a second" or "about once
      every X seconds" variety and several showed up in the "what wakes the
      cpu up" profiles that the tickless patches provide.  Some timers are
      highly dynamic based on network load; but even on low activity systems
      they still show up so the rounding is done only in cases of low
      activity, allowing higher frequency timers in the high activity case.
      
      The various hardware watchdogs are an obvious case; they run every 2
      seconds but aren't otherwise specific of exactly when they need to
      run.
      Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      f5a6e01c
  17. 02 Dec, 2006 2 commits