summaryrefslogtreecommitdiff
path: root/net/sched/sch_generic.c
AgeCommit message (Collapse)Author
2011-07-15Remove redundant variable/code in __qdisc_runKrishna Kumar
Remove redundant variable "work". Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-06-27net_sched: fix dequeuer fairnessjamal
Results on dummy device can be seen in my netconf 2011 slides. These results are for a 10Gige IXGBE intel nic - on another i5 machine, very similar specs to the one used in the netconf2011 results. It turns out - this is a hell lot worse than dummy and so this patch is even more beneficial for 10G. Test setup: ---------- System under test sending packets out. Additional box connected directly dropping packets. Installed prio qdisc on the eth device and default netdev default length of 1000 used as is. The 3 prio bands each were set to 100 (didnt factor in the results). 5 packet runs were made and the middle 3 picked. results ------- The "cpu" column indicates the which cpu the sample was taken on, The "Pkt runx" carries the number of packets a cpu dequeued when forced to be in the "dequeuer" role. The "avg" for each run is the number of times each cpu should be a "dequeuer" if the system was fair. 3.0-rc4 (plain) cpu Pkt run1 Pkt run2 Pkt run3 ================================================ cpu0 21853354 21598183 22199900 cpu1 431058 473476 393159 cpu2 481975 477529 458466 cpu3 23261406 23412299 22894315 avg 11506948 11490372 11486460 3.0-rc4 with patch and default weight 64 cpu Pkt run1 Pkt run2 Pkt run3 ================================================ cpu0 13205312 13109359 13132333 cpu1 10189914 10159127 10122270 cpu2 10213871 10124367 10168722 cpu3 13165760 13164767 13096705 avg 11693714 11639405 11630008 As you can see the system is still not perfect but is a lot better than what it was before... At the moment we use the old backlog weight, weight_p which is 64 packets. It seems to be reasonably fine with that value. The system could be made more fair if we reduce the weight_p (as per my presentation), but we are going to affect the shared backlog weight. Unless deemed necessary, I think the default value is fine. If not we could add yet another knob. Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-06-06net: Rework netdev_drivername() to avoid warning.David S. Miller
This interface uses a temporary buffer, but for no real reason. And now can generate warnings like: net/sched/sch_generic.c: In function dev_watchdog net/sched/sch_generic.c:254:10: warning: unused variable drivername Just return driver->name directly or "". Reported-by: Connor Hansen <cmdkhh@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-22net: avoid synchronize_rcu() in dev_deactivate_manyEric Dumazet
dev_deactivate_many() issues one synchronize_rcu() call after qdiscs set to noop_qdisc. This call is here to make sure they are no outstanding qdisc-less dev_queue_xmit calls before returning to caller. But in dismantle phase, we dont have to wait, because we wont activate again the device, and we are going to wait one rcu grace period later in rollback_registered_many(). After this patch, device dismantle uses one synchronize_net() and one rcu_barrier() call only, so we have a ~30% speedup and a smaller RTNL latency. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Patrick McHardy <kaber@trash.net>, CC: Ben Greear <greearb@candelatech.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-03Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/bnx2x/bnx2x.h
2011-03-03net_sched: reduce fifo qdisc sizeEric Dumazet
Because of various alignements [SLUB / qdisc], we use 512 bytes of memory for one {p|b}fifo qdisc, instead of 256 bytes on 64bit arches and 192 bytes on 32bit ones. Move the "u32 limit" inside "struct Qdisc" (no impact on other qdiscs) Change qdisc_alloc(), first trying a regular allocation before an oversized one. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-20net: Fix more stale on-stack list_head objects.Eric W. Biederman
From: Eric W. Biederman <ebiederm@xmission.com> In the beginning with batching unreg_list was a list that was used only once in the lifetime of a network device (I think). Now we have calls using the unreg_list that can happen multiple times in the life of a network device like dev_deactivate and dev_close that are also using the unreg_list. In addition in unregister_netdevice_queue we also do a list_move because for devices like veth pairs it is possible that unregister_netdevice_queue will be called multiple times. So I think the change below to fix dev_deactivate which Eric D. missed will fix this problem. Now to go test that. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-21net_sched: TCQ_F_CAN_BYPASS generalizationEric Dumazet
Now qdisc stab is handled before TCQ_F_CAN_BYPASS test in __dev_xmit_skb(), we can generalize TCQ_F_CAN_BYPASS to other qdiscs than pfifo_fast : pfifo, bfifo, pfifo_head_drop and sfq SFQ is special because it can have external classifiers, and in these cases, we cannot bypass queue discipline (packet could be dropped by classifier) without admin asking it, or further changes. Its worth doing this, especially for SFQ, avoiding dirtying memory in case no packets are already waiting in queue. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-20net_sched: RCU conversion of stabEric Dumazet
This patch converts stab qdisc management to RCU, so that we can perform the qdisc_calculate_pkt_len() call before getting qdisc lock. This shortens the lock's held time in __dev_xmit_skb(). This permits more qdiscs to get TCQ_F_CAN_BYPASS status, avoiding lot of cache misses and so reducing latencies. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Patrick McHardy <kaber@trash.net> CC: Jesper Dangaard Brouer <hawk@diku.dk> CC: Jarek Poplawski <jarkao2@gmail.com> CC: Jamal Hadi Salim <hadi@cyberus.ca> CC: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-19net_sched: cleanupsEric Dumazet
Cleanup net/sched code to current CodingStyle and practices. Reduce inline abuse Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-19net_sched: implement a root container qdisc sch_mqprioJohn Fastabend
This implements a mqprio queueing discipline that by default creates a pfifo_fast qdisc per tx queue and provides the needed configuration interface. Using the mqprio qdisc the number of tcs currently in use along with the range of queues alloted to each class can be configured. By default skbs are mapped to traffic classes using the skb priority. This mapping is configurable. Configurable parameters, struct tc_mqprio_qopt { __u8 num_tc; __u8 prio_tc_map[TC_BITMASK + 1]; __u8 hw; __u16 count[TC_MAX_QUEUE]; __u16 offset[TC_MAX_QUEUE]; }; Here the count/offset pairing give the queue alignment and the prio_tc_map gives the mapping from skb->priority to tc. The hw bit determines if the hardware should configure the count and offset values. If the hardware bit is set then the operation will fail if the hardware does not implement the ndo_setup_tc operation. This is to avoid undetermined states where the hardware may or may not control the queue mapping. Also minimal bounds checking is done on the count/offset to verify a queue does not exceed num_tx_queues and that queue ranges do not overlap. Otherwise it is left to user policy or hardware configuration to create useful mappings. It is expected that hardware QOS schemes can be implemented by creating appropriate mappings of queues in ndo_tc_setup(). One expected use case is drivers will use the ndo_setup_tc to map queue ranges onto 802.1Q traffic classes. This provides a generic mechanism to map network traffic onto these traffic classes and removes the need for lower layer drivers to know specifics about traffic types. Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-16net: factorize sync-rcu call in unregister_netdevice_manyOctavian Purdila
Add dev_close_many and dev_deactivate_many to factorize another sync-rcu operation on the netdevice unregister path. $ modprobe dummy numdummies=10000 $ ip link set dev dummy* up $ time rmmod dummy Without the patch With the patch real 0m 24.63s real 0m 5.15s user 0m 0.00s user 0m 0.00s sys 0m 6.05s sys 0m 5.14s Signed-off-by: Octavian Purdila <opurdila@ixiacom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-01net sched: use xps information for qdisc NUMA affinityEric Dumazet
Allocate qdisc memory according to NUMA properties of cpus included in xps map. To be effective, qdisc should be (re)setup after changes of /sys/class/net/eth<n>/queues/tx-<n>/xps_cpus I added a numa_node field in struct netdev_queue, containing NUMA node if all cpus included in xps_cpus share same node, else -1. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-28net: add netif_tx_queue_frozen_or_stoppedEric Dumazet
When testing struct netdev_queue state against FROZEN bit, we also test XOFF bit. We can test both bits at once and save some cycles. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21net_sched: remove the unused parameter of qdisc_create_dflt()Changli Gao
The first parameter dev isn't in use in qdisc_create_dflt(). Signed-off-by: Changli Gao <xiaosuo@gmail.com> Acked-by: Jamal Hadi Salim <hadi@cyberus.ca> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21net/sched: fix missing spinlock initEric Dumazet
Under network load, doing : tc qdisc del dev eth0 root triggers : [ 167.193087] BUG: spinlock bad magic on CPU#3, udpflood/4928 [ 167.193139] lock: c15bc324, .magic: 00000000, .owner: <none>/-1, .owner_cpu: -1 [ 167.193193] Pid: 4928, comm: udpflood Not tainted 2.6.36-rc7-11417-g215340c-dirty #323 [ 167.193245] Call Trace: [ 167.193292] [<c13abaa0>] ? printk+0x18/0x20 [ 167.193342] [<c11afb53>] spin_bug+0xa3/0xf0 [ 167.193389] [<c11afcdd>] do_raw_spin_lock+0x7d/0x160 [ 167.193440] [<c1313d4e>] ? __dev_xmit_skb+0x27e/0x2b0 [ 167.193496] [<c107382b>] ? trace_hardirqs_on+0xb/0x10 [ 167.193545] [<c13ae99a>] _raw_spin_lock+0x3a/0x40 [ 167.193593] [<c1313d4e>] ? __dev_xmit_skb+0x27e/0x2b0 [ 167.193641] [<c1313d4e>] __dev_xmit_skb+0x27e/0x2b0 commit 79640a4ca695 (add additional lock to qdisc to increase throughput) forgot to initialize noop_qdisc and noqueue_qdisc busylock Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-05net: dynamic ingress_queue allocationEric Dumazet
ingress being not used very much, and net_device->ingress_queue being quite a big object (128 or 256 bytes), use a dynamic allocation if needed (tc qdisc add dev eth0 ingress ...) dev_ingress_queue(dev) helper should be used only with RTNL taken. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-29net: rename netdev rx_queue to ingress_queueEric Dumazet
There is some confusion with rx_queue name after RPS, and net drivers private rx_queue fields. I suggest to rename "struct net_device"->rx_queue to ingress_queue. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-19net: this_cpu_xxx conversionsEric Dumazet
Use modern this_cpu_xxx() api, saving few bytes on x86 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-02net: add additional lock to qdisc to increase throughputEric Dumazet
When many cpus compete for sending frames on a given qdisc, the qdisc spinlock suffers from very high contention. The cpu owning __QDISC_STATE_RUNNING bit has same priority to acquire the lock, and cannot dequeue packets fast enough, since it must wait for this lock for each dequeued packet. One solution to this problem is to force all cpus spinning on a second lock before trying to get the main lock, when/if they see __QDISC_STATE_RUNNING already set. The owning cpu then compete with at most one other cpu for the main lock, allowing for higher dequeueing rate. Based on a previous patch from Alexander Duyck. I added the heuristic to avoid the atomic in fast path, and put the new lock far away from the cache line used by the dequeue worker. Also try to release the busylock lock as late as possible. Tests with following script gave a boost from ~50.000 pps to ~600.000 pps on a dual quad core machine (E5450 @3.00GHz), tg3 driver. (A single netperf flow can reach ~800.000 pps on this platform) for j in `seq 0 3`; do for i in `seq 0 7`; do netperf -H 192.168.0.1 -t UDP_STREAM -l 60 -N -T $i -- -m 6 & done done Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-02net: Define accessors to manipulate QDISC_STATE_RUNNINGEric Dumazet
Define three helpers to manipulate QDISC_STATE_RUNNIG flag, that a second patch will move on another location. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-31arp_notify: allow drivers to explicitly request a notification event.Ian Campbell
Currently such notifications are only generated when the device comes up or the address changes. However one use case for these notifications is to enable faster network recovery after a virtual machine migration (by causing switches to relearn their MAC tables). A migration appears to the network stack as a temporary loss of carrier and therefore does not trigger either of the current conditions. Rather than adding carrier up as a trigger (which can cause issues when interfaces a flapping) simply add an interface which the driver can use to explicitly trigger the notification. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Cc: Stephen Hemminger <shemminger@linux-foundation.org> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: David S. Miller <davem@davemloft.net> Cc: netdev@vger.kernel.org Cc: stable@kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-17net: add a noref bit on skb dstEric Dumazet
Use low order bit of skb->_skb_dst to tell dst is not refcounted. Change _skb_dst to _skb_refdst to make sure all uses are catched. skb_dst() returns the dst, regardless of noref bit set or not, but with a lockdep check to make sure a noref dst is not given if current user is not rcu protected. New skb_dst_set_noref() helper to set an notrefcounted dst on a skb. (with lockdep check) skb_dst_drop() drops a reference only if skb dst was refcounted. skb_dst_force() helper is used to force a refcount on dst, when skb is queued and not anymore RCU protected. Use skb_dst_force() in __sk_add_backlog(), __dev_xmit_skb() if !IFF_XMIT_DST_RELEASE or skb enqueued on qdisc queue, in sock_queue_rcv_skb(), in __nf_queue(). Use skb_dst_force() in dev_requeue_skb(). Note: dst_use_noref() still dirties dst, we might transform it later to do one dirtying per jiffies. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-02net: fix softnet_statChangli Gao
Per cpu variable softnet_data.total was shared between IRQ and SoftIRQ context without any protection. And enqueue_to_backlog should update the netdev_rx_stat of the target CPU. This patch renames softnet_data.total to softnet_data.processed: the number of packets processed in uppper levels(IP stacks). softnet_stat data is moved into softnet_data. Signed-off-by: Changli Gao <xiaosuo@gmail.com> ---- include/linux/netdevice.h | 17 +++++++---------- net/core/dev.c | 26 ++++++++++++-------------- net/sched/sch_generic.c | 2 +- 3 files changed, 20 insertions(+), 25 deletions(-) Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-11Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/stmmac/stmmac_main.c drivers/net/wireless/wl12xx/wl1271_cmd.c drivers/net/wireless/wl12xx/wl1271_main.c drivers/net/wireless/wl12xx/wl1271_spi.c net/core/ethtool.c net/mac80211/scan.c
2010-04-01gen_estimator: deadlock fixEric Dumazet
One of my test machine got a deadlock during "tc" sessions, adding/deleting classes & filters, using traffic estimators. After some analysis, I believe we have a potential use after free case in est_timer() : spin_lock(e->stats_lock); << HERE >> read_lock(&est_lock); if (e->bstats == NULL) << TEST >> goto skip; Test is done a bit late, because after estimator is killed, and before rcu grace period elapsed, we might already have freed/reuse memory where e->stats_locks points to (some qdisc->q.lock) A possible fix is to respect a rcu grace period at Qdisc dismantle time. On 64bit, sizeof(struct Qdisc) is exactly 192 bytes. Adding 16 bytes to it (for struct rcu_head) is a problem because it might change performance, given QDISC_ALIGNTO is 32 bytes. This is why I also change QDISC_ALIGNTO to 64 bytes, to satisfy most current alignment requirements. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit 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>
2009-11-15net: Optimize hard_start_xmit() return checkingJarek Poplawski
Recent changes in the TX error propagation require additional checking and masking of values returned from hard_start_xmit(), mainly to separate cases where skb was consumed. This aim can be simplified by changing the order of NETDEV_TX and NET_XMIT codes, because the latter are treated similarly to negative (ERRNO) values. After this change much simpler dev_xmit_complete() is also used in sch_direct_xmit(), so it is moved to netdevice.h. Additionally NET_RX definitions in netdevice.h are moved up from between TX codes to avoid confusion while reading the TX comment. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-13net: allow to propagate errors through ->ndo_hard_start_xmit()Patrick McHardy
Currently the ->ndo_hard_start_xmit() callbacks are only permitted to return one of the NETDEV_TX codes. This prevents any kind of error propagation for virtual devices, like queue congestion of the underlying device in case of layered devices, or unreachability in case of tunnels. This patches changes the NET_XMIT codes to avoid clashes with the NETDEV_TX codes and changes the two callers of dev_hard_start_xmit() to expect either errno codes, NET_XMIT codes or NETDEV_TX codes as return value. In case of qdisc_restart(), all non NETDEV_TX codes are mapped to NETDEV_TX_OK since no error propagation is possible when using qdiscs. In case of dev_queue_xmit(), the error is propagated upwards. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-06net_sched: add classful multiqueue dummy schedulerDavid S. Miller
This patch adds a classful dummy scheduler which can be used as root qdisc for multiqueue devices and exposes each device queue as a child class. This allows to address queues individually and graft them similar to regular classes. Additionally it presents an accumulated view of the statistics of all real root qdiscs in the dummy root. Two new callbacks are added to the qdisc_ops and qdisc_class_ops: - cl_ops->select_queue selects the tx queue number for new child classes. - qdisc_ops->attach() overrides root qdisc device grafting to attach non-shared qdiscs to the queues. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-06net_sched: move dev_graft_qdisc() to sch_generic.cPatrick McHardy
It will be used in a following patch by the multiqueue qdisc. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-06net_sched: reintroduce dev->qdisc for use by sch_apiPatrick McHardy
Currently the multiqueue integration with the qdisc API suffers from a few problems: - with multiple queues, all root qdiscs use the same handle. This means they can't be exposed to userspace in a backwards compatible fashion. - all API operations always refer to queue number 0. Newly created qdiscs are automatically shared between all queues, its not possible to address individual queues or restore multiqueue behaviour once a shared qdisc has been attached. - Dumps only contain the root qdisc of queue 0, in case of non-shared qdiscs this means the statistics are incomplete. This patch reintroduces dev->qdisc, which points to the (single) root qdisc from userspace's point of view. Currently it either points to the first (non-shared) default qdisc, or a qdisc shared between all queues. The following patches will introduce a classful dummy qdisc, which will be used as root qdisc and contain the per-queue qdiscs as children. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-30pkt_sched: Fix resource limiting in pfifo_fastKrishna Kumar
pfifo_fast_enqueue has this check: if (skb_queue_len(list) < qdisc_dev(qdisc)->tx_queue_len) { which allows each band to enqueue upto tx_queue_len skbs for a total of 3*tx_queue_len skbs. I am not sure if this was the intention of limiting in qdisc. Patch compiled and 32 simultaneous netperf testing ran fine. Also: # tc -s qdisc show dev eth2 qdisc pfifo_fast 0: root bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1 Sent 16835026752 bytes 373116 pkt (dropped 0, overlimits 0 requeues 25) rate 0bit 0pps backlog 0b 0p requeues 25 Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-29Speed-up pfifo_fast lookup using a private bitmapKrishna Kumar
Maintain a per-qdisc bitmap for pfifo_fast giving availability of skbs for each band. This allows faster lookup for a skb when there are no high priority skbs. Also, it helps in (rare) cases when there are no skbs on the list, where an immediate lookup is faster than iterating through the three bands. Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-06net: Avoid enqueuing skb for default qdiscsKrishna Kumar
dev_queue_xmit enqueue's a skb and calls qdisc_run which dequeue's the skb and xmits it. In most cases, the skb that is enqueue'd is the same one that is dequeue'd (unless the queue gets stopped or multiple cpu's write to the same queue and ends in a race with qdisc_run). For default qdiscs, we can remove the redundant enqueue/dequeue and simply xmit the skb since the default qdisc is work-conserving. The patch uses a new flag - TCQ_F_CAN_BYPASS to identify the default fast queue. The controversial part of the patch is incrementing qlen when a skb is requeued - this is to avoid checks like the second line below: + } else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) && >> !q->gso_skb && + !test_and_set_bit(__QDISC_STATE_RUNNING, &q->state)) { Results of a 2 hour testing for multiple netperf sessions (1, 2, 4, 8, 12 sessions on a 4 cpu system-X). The BW numbers are aggregate Mb/s across iterations tested with this version on System-X boxes with Chelsio 10gbps cards: ---------------------------------- Size | ORG BW NEW BW | ---------------------------------- 128K | 156964 159381 | 256K | 158650 162042 | ---------------------------------- Changes from ver1: 1. Move sch_direct_xmit declaration from sch_generic.h to pkt_sched.h 2. Update qdisc basic statistics for direct xmit path. 3. Set qlen to zero in qdisc_reset. 4. Changed some function names to more meaningful ones. Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-17net: tx scalability works : trans_startEric Dumazet
struct net_device trans_start field is a hot spot on SMP and high performance devices, particularly multi queues ones, because every transmitter dirties it. Is main use is tx watchdog and bonding alive checks. But as most devices dont use NETIF_F_LLTX, we have to lock a netdev_queue before calling their ndo_start_xmit(). So it makes sense to move trans_start from net_device to netdev_queue. Its update will occur on a already present (and in exclusive state) cache line, for free. We can do this transition smoothly. An old driver continue to update dev->trans_start, while an updated one updates txq->trans_start. Further patches could also put tx_bytes/tx_packets counters in netdev_queue to avoid dirtying dev->stats (vlan device comes to mind) Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-20Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/ixgbe/ixgbe_main.c include/net/mac80211.h net/phonet/af_phonet.c
2008-11-19netdev: network device operations infrastructureStephen Hemminger
This patch changes the network device internal API to move adminstrative operations out of the network device structure and into a separate structure. This patch involves some hackery to maintain compatablity between the new and old model, so all 300+ drivers don't have to be changed at once. For drivers that aren't converted yet, the netdevice_ops virt function list still resides in the net_device structure. For old protocols, the new net_device_ops are copied out to the old net_device pointers. After the transistion is completed the nag message can be changed to an WARN_ON, and the compatiablity code can be made configurable. Some function pointers aren't moved: * destructor can't be in net_device_ops because it may need to be referenced after the module is unloaded. * neighbor setup is manipulated in a couple of places that need special consideration * hard_start_xmit is in the fast path for transmit. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-19net: Do not fire linkwatch events until the device is registered.David S. Miller
Several device drivers try to do things like netif_carrier_off() before register_netdev() is invoked. This is bogus, but too many drivers do this to fix them all up in one go. Reported-by: Folkert van Heusden <folkert@vanheusden.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-13pkt_sched: Remove qdisc->ops->requeue() etc.Jarek Poplawski
After implementing qdisc->ops->peek() and changing sch_netem into classless qdisc there are no more qdisc->ops->requeue() users. This patch removes this method with its wrappers (qdisc_requeue()), and also unused qdisc->requeue structure. There are a few minor fixes of warnings (htb_enqueue()) and comments btw. The idea to kill ->requeue() and a similar patch were first developed by David S. Miller. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-03pkt_sched: sch_generic: Kfree gso_skb in qdisc_reset()Jarek Poplawski
Since gso_skb is re-used for qdisc_peek_dequeued(), and this skb is counted in the qdisc->q.qlen, it has to be kfreed during qdisc_reset() when qlen is zeroed. With help from David S. Miller <davem@davemloft.net> Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-31pkt_sched: sch_generic: Add generic qdisc->ops->peek() implementation.Jarek Poplawski
With feedback from Patrick McHardy. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-19pkt_sched: sch_generic: Fix oops in sch_teqlJarek Poplawski
After these commands: # modprobe sch_teql # tc qdisc add dev eth0 root teql0 # tc qdisc del dev eth0 root we get an oops in teql_destroy() when spin_lock is taken from a null qdisc_sleeping pointer. It's because at the moment teql0 dev haven't been activated yet, and a qdisc_root_sleeping() is pointing to noop qdisc's netdev_queue with qdisc_sleeping uninitialized. This patch fixes this both for noop and noqueue netdev_queues to avoid similar problems in the future. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-08pkt_sched: Update qdisc requeue stats in dev_requeue_skb()Jarek Poplawski
After the last change of requeuing there is no info about such incidents in tc stats. This patch updates the counter, but we should consider this should differ from previous stats because of additional checks preventing to repeat this. On the other hand, previous stats didn't include requeuing of gso_segmented skbs. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-06pkt_sched: Simplify dev_requeue_skb and dequeue_skbJarek Poplawski
qdisc->requeue was planned to universally replace all requeuing code, but at the top level we never requeue more than one skb, so qdisc-> gso_skb is enough for this. qdisc->requeue would be used on the lower levels only for one level deep requeuing (like in sch_hfsc) after finishing all the changes. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-06pkt_sched: Fix handling of gso skbs on requeuingJarek Poplawski
Jay Cliburn noticed and diagnosed a bug triggered in dev_gso_skb_destructor() after last change from qdisc->gso_skb to qdisc->requeue list. Since gso_segmented skbs can't be queued to another list this patch brings back qdisc->gso_skb for them. Reported-by: Jay Cliburn <jcliburn@gmail.com> Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-09-22pkt_sched: Check the state of tx_queue in dequeue_skb()Jarek Poplawski
Check in dequeue_skb() the state of tx_queue for requeued skb to save on locking and re-requeuing, and possibly remove the current check in qdisc_run(). Based on the idea of Alexander Duyck. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-09-22pkt_sched: Always use q->requeue in dev_requeue_skb().David S. Miller
There is no reason to call into the complicated qdiscs just to remember the last SKB where we found the device blocked. The SKB is outside of the qdiscs realm at this point. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-09-22pkt_sched: Make qdisc->gso_skb a list.David S. Miller
The idea is that we can use this to get rid of ->requeue(). Signed-off-by: David S. Miller <davem@davemloft.net>
2008-09-08warn: Turn the netdev timeout WARN_ON() into a WARN()Arjan van de Ven
this patch turns the netdev timeout WARN_ON_ONCE() into a WARN_ONCE(), so that the device and driver names are inside the warning message. This helps automated tools like kerneloops.org to collect the data and do statistics, as well as making it more likely that humans cut-n-paste the important message as part of a bugreport. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>