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2018-11-14net: sched: red: notify drivers about RED's limit parameterJakub Kicinski1-0/+1
RED qdisc's limit parameter changes the behaviour of the qdisc, for instance if it's set to 0 qdisc will drop all the packets. When replace operation happens and parameter is set to non-0 a new fifo qdisc will be instantiated and replace the old child qdisc which will be destroyed. Drivers need to know the parameter, even if they don't impose the actual limit to be able to reliably reconstruct the Qdisc hierarchy. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: John Hurley <john.hurley@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-14net: sched: red: offload a graft notificationJakub Kicinski1-0/+17
Drivers offloading Qdiscs should have reasonable certainty the offloaded behaviour matches the SW path. This is impossible if the driver does not know about all Qdiscs or when Qdiscs move and are reused. Send a graft notification from RED. The drivers are expected to simply stop offloading the Qdisc, if a non-standard child is ever grafted onto it. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: John Hurley <john.hurley@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-08net: sched: red: inform offloads about harddrop settingJakub Kicinski1-0/+1
To mirror software behaviour on offload more precisely inform the drivers about the state of the harddrop flag. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: John Hurley <john.hurley@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-08net: sched: red: delay destroying child qdisc on replaceJakub Kicinski1-2/+6
Move destroying of the old child qdisc outside of the sch_tree_lock() section. This should improve the software qdisc replace but is even more important for offloads. Firstly calling offloads under a spin lock is best avoided. Secondly the destroy event of existing child would have been sent to the offload device before the replace, causing confusion. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: John Hurley <john.hurley@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-08net: sched: red: remove unnecessary red_dump_offload_stats parameterJakub Kicinski1-2/+2
Offload dump helper does not use opt parameter, remove it. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: John Hurley <john.hurley@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-08net: sched: add an offload dump helperJakub Kicinski1-16/+1
Qdisc dump operation of offload-capable qdiscs performs a few extra steps which are identical among all the qdiscs. Add a helper to share this code. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: John Hurley <john.hurley@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-25net: sched: rename qdisc_destroy() to qdisc_put()Vlad Buslov1-2/+2
Current implementation of qdisc_destroy() decrements Qdisc reference counter and only actually destroy Qdisc if reference counter value reached zero. Rename qdisc_destroy() to qdisc_put() in order for it to better describe the way in which this function currently implemented and used. Extract code that deallocates Qdisc into new private qdisc_destroy() function. It is intended to be shared between regular qdisc_put() and its unlocked version that is introduced in next patch in this series. Signed-off-by: Vlad Buslov <vladbu@mellanox.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-18net: sched: red: avoid hashing NULL childPaolo Abeni1-2/+3
Hangbin reported an Oops triggered by the syzkaller qdisc rules: kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN PTI Modules linked in: sch_red CPU: 0 PID: 28699 Comm: syz-executor5 Not tainted 4.17.0-rc4.kcov #1 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:qdisc_hash_add+0x26/0xa0 RSP: 0018:ffff8800589cf470 EFLAGS: 00010203 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff824ad971 RDX: 0000000000000007 RSI: ffffc9000ce9f000 RDI: 000000000000003c RBP: 0000000000000001 R08: ffffed000b139ea2 R09: ffff8800589cf4f0 R10: ffff8800589cf50f R11: ffffed000b139ea2 R12: ffff880054019fc0 R13: ffff880054019fb4 R14: ffff88005c0af600 R15: ffff880054019fb0 FS: 00007fa6edcb1700(0000) GS:ffff88005ce00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000740 CR3: 000000000fc16000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: red_change+0x2d2/0xed0 [sch_red] qdisc_create+0x57e/0xef0 tc_modify_qdisc+0x47f/0x14e0 rtnetlink_rcv_msg+0x6a8/0x920 netlink_rcv_skb+0x2a2/0x3c0 netlink_unicast+0x511/0x740 netlink_sendmsg+0x825/0xc30 sock_sendmsg+0xc5/0x100 ___sys_sendmsg+0x778/0x8e0 __sys_sendmsg+0xf5/0x1b0 do_syscall_64+0xbd/0x3b0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x450869 RSP: 002b:00007fa6edcb0c48 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fa6edcb16b4 RCX: 0000000000450869 RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000013 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000008778 R14: 0000000000702838 R15: 00007fa6edcb1700 Code: e9 0b fe ff ff 0f 1f 44 00 00 55 53 48 89 fb 89 f5 e8 3f 07 f3 fe 48 8d 7b 3c 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 51 RIP: qdisc_hash_add+0x26/0xa0 RSP: ffff8800589cf470 When a red qdisc is updated with a 0 limit, the child qdisc is left unmodified, no additional scheduler is created in red_change(), the 'child' local variable is rightfully NULL and must not add it to the hash table. This change addresses the above issue moving qdisc_hash_add() right after the child qdisc creation. It additionally removes unneeded checks for noop_qdisc. Reported-by: Hangbin Liu <liuhangbin@gmail.com> Fixes: 49b499718fa1 ("net: sched: make default fifo qdiscs appear in the dump") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-17net: sched: red: don't reset the backlog on every stat dumpJakub Kicinski1-1/+1
Commit 0dfb33a0d7e2 ("sch_red: report backlog information") copied child's backlog into RED's backlog. Back then RED did not maintain its own backlog counts. This has changed after commit 2ccccf5fb43f ("net_sched: update hierarchical backlog too") and commit d7f4f332f082 ("sch_red: update backlog as well"). Copying is no longer necessary. Tested: $ tc -s qdisc show dev veth0 qdisc red 1: root refcnt 2 limit 400000b min 30000b max 30000b ecn Sent 20942 bytes 221 pkt (dropped 0, overlimits 0 requeues 0) backlog 1260b 14p requeues 14 marked 0 early 0 pdrop 0 other 0 qdisc tbf 2: parent 1: rate 1Kbit burst 15000b lat 3585.0s Sent 20942 bytes 221 pkt (dropped 0, overlimits 138 requeues 0) backlog 1260b 14p requeues 14 Recently RED offload was added. We need to make sure drivers don't depend on resetting the stats. This means backlog should be treated like any other statistic: total_stat = new_hw_stat - prev_hw_stat; Adjust mlxsw. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Nogah Frankel <nogahf@mellanox.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-10net: sch: red: Change offloaded xstats to be incrementalNogah Frankel1-16/+8
Change the value of the xstats requested from the driver for offloaded RED to be incremental, like the normal stats. It increases consistency - if a qdisc stops being offloaded its xstats don't change. Signed-off-by: Nogah Frankel <nogahf@mellanox.com> Reviewed-by: Yuval Mintz <yuvalm@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-02net_sch: red: Fix the new offload indicationNogah Frankel1-12/+14
Update the offload flag, TCQ_F_OFFLOADED, in each dump call (and ignore the offloading function return value in relation to this flag). This is done because a qdisc is being initialized, and therefore offloaded before being grafted. Since the ability of the driver to offload the qdisc depends on its location, a qdisc can be offloaded and un-offloaded by graft calls, that doesn't effect the qdisc itself. Fixes: 428a68af3a7c ("net: sched: Move to new offload indication in RED" Signed-off-by: Nogah Frankel <nogahf@mellanox.com> Reviewed-by: Yuval Mintz <yuvalm@mellanox.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-21net: sch: api: add extack support in qdisc_create_dfltAlexander Aring1-1/+2
This patch adds extack support for the function qdisc_create_dflt which is a common used function in the tc subsystem. Callers which are interested in the receiving error can assign extack to get a more detailed information why qdisc_create_dflt failed. The function qdisc_create_dflt will also call an init callback which can fail by any per-qdisc specific handling. Cc: David Ahern <dsahern@gmail.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Alexander Aring <aring@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-21net: sched: sch: add extack for graft callbackAlexander Aring1-1/+1
This patch adds extack support for graft callback to prepare per-qdisc specific changes for extack. Cc: David Ahern <dsahern@gmail.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Alexander Aring <aring@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-21net: sched: sch: add extack for change qdisc opsAlexander Aring1-2/+3
This patch adds extack support for change callback for qdisc ops structtur to prepare per-qdisc specific changes for extack. Cc: David Ahern <dsahern@gmail.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Alexander Aring <aring@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-21net: sched: sch: add extack for init callbackAlexander Aring1-1/+2
This patch adds extack support for init callback to prepare per-qdisc specific changes for extack. Cc: David Ahern <dsahern@gmail.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Alexander Aring <aring@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-15net: sched: Move to new offload indication in REDYuval Mintz1-16/+15
Let RED utilize the new internal flag, TCQ_F_OFFLOADED, to mark a given qdisc as offloaded instead of using a dedicated indication. Also, change internal logic into looking at said flag when possible. Fixes: 602f3baf2218 ("net_sch: red: Add offload ability to RED qdisc") Signed-off-by: Yuval Mintz <yuvalm@mellanox.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-05net_sched: red: Avoid illegal valuesNogah Frankel1-0/+2
Check the qmin & qmax values doesn't overflow for the given Wlog value. Check that qmin <= qmax. Fixes: a783474591f2 ("[PKT_SCHED]: Generic RED layer") Signed-off-by: Nogah Frankel <nogahf@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-13net/sched/sch_red.c: work around gcc-4.4.4 anon union initializer issueAndrew Morton1-5/+9
gcc-4.4.4 (at lest) has issues with initializers and anonymous unions: net/sched/sch_red.c: In function 'red_dump_offload': net/sched/sch_red.c:282: error: unknown field 'stats' specified in initializer net/sched/sch_red.c:282: warning: initialization makes integer from pointer without a cast net/sched/sch_red.c:283: error: unknown field 'stats' specified in initializer net/sched/sch_red.c:283: warning: initialization makes integer from pointer without a cast net/sched/sch_red.c: In function 'red_dump_stats': net/sched/sch_red.c:352: error: unknown field 'xstats' specified in initializer net/sched/sch_red.c:352: warning: initialization makes integer from pointer without a cast Work around this. Fixes: 602f3baf2218 ("net_sch: red: Add offload ability to RED qdisc") Cc: Nogah Frankel <nogahf@mellanox.com> Cc: Jiri Pirko <jiri@mellanox.com> Cc: Simon Horman <simon.horman@netronome.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-08net_sch: red: Add offload ability to RED qdiscNogah Frankel1-0/+79
Add the ability to offload RED qdisc by using ndo_setup_tc. There are four commands for RED offloading: * TC_RED_SET: handles set and change. * TC_RED_DESTROY: handle qdisc destroy. * TC_RED_STATS: update the qdiscs counters (given as reference) * TC_RED_XSTAT: returns red xstats. Whether RED is being offloaded is being determined every time dump action is being called because parent change of this qdisc could change its offload state but doesn't require any RED function to be called. Signed-off-by: Nogah Frankel <nogahf@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-18net: sched: Convert timers to use timer_setup()Kees Cook1-4/+6
In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Add pointer back to Qdisc. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Jiri Pirko <jiri@resnulli.us> Cc: "David S. Miller" <davem@davemloft.net> Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25net_sched: remove tc class reference countingWANG Cong1-7/+2
For TC classes, their ->get() and ->put() are always paired, and the reference counting is completely useless, because: 1) For class modification and dumping paths, we already hold RTNL lock, so all of these ->get(),->change(),->put() are atomic. 2) For filter bindiing/unbinding, we use other reference counter than this one, and they should have RTNL lock too. 3) For ->qlen_notify(), it is special because it is called on ->enqueue() path, but we already hold qdisc tree lock there, and we hold this tree lock when graft or delete the class too, so it should not be gone or changed until we release the tree lock. Therefore, this patch removes ->get() and ->put(), but: 1) Adds a new ->find() to find the pointer to a class by classid, no refcnt. 2) Move the original class destroy upon the last refcnt into ->delete(), right after releasing tree lock. This is fine because the class is already removed from hash when holding the lock. For those who also use ->put() as ->unbind(), just rename them to reflect this change. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-13netlink: pass extended ACK struct to parsing functionsJohannes Berg1-1/+1
Pass the new extended ACK reporting struct to all of the generic netlink parsing functions. For now, pass NULL in almost all callers (except for some in the core.) Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-12net: sched: make default fifo qdiscs appear in the dumpJiri Kosina1-0/+2
The original reason [1] for having hidden qdiscs (potential scalability issues in qdisc_match_from_root() with single linked list in case of large amount of qdiscs) has been invalidated by 59cc1f61f0 ("net: sched: convert qdisc linked list to hashtable"). This allows us for bringing more clarity and determinism into the dump by making default pfifo qdiscs visible. We're not turning this on by default though, at it was deemed [2] too intrusive / unnecessary change of default behavior towards userspace. Instead, TCA_DUMP_INVISIBLE netlink attribute is introduced, which allows applications to request complete qdisc hierarchy dump, including the ones that have always been implicit/invisible. Singleton noop_qdisc stays invisible, as teaching the whole infrastructure about singletons would require quite some surgery with very little gain (seeing no qdisc or seeing noop qdisc in the dump is probably setting the same user expectation). [1] http://lkml.kernel.org/r/1460732328.10638.74.camel@edumazet-glaptop3.roam.corp.google.com [2] http://lkml.kernel.org/r/20161021.105935.1907696543877061916.davem@davemloft.net Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-25net_sched: drop packets after root qdisc lock is releasedEric Dumazet1-3/+4
Qdisc performance suffers when packets are dropped at enqueue() time because drops (kfree_skb()) are done while qdisc lock is held, delaying a dequeue() draining the queue. Nominal throughput can be reduced by 50 % when this happens, at a time we would like the dequeue() to proceed as fast as possible. Even FQ is vulnerable to this problem, while one of FQ goals was to provide some flow isolation. This patch adds a 'struct sk_buff **to_free' parameter to all qdisc->enqueue(), and in qdisc_drop() helper. I measured a performance increase of up to 12 %, but this patch is a prereq so that future batches in enqueue() can fly. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-10Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-0/+3
Conflicts: net/sched/act_police.c net/sched/sch_drr.c net/sched/sch_hfsc.c net/sched/sch_prio.c net/sched/sch_red.c net/sched/sch_tbf.c In net-next the drop methods of the packet schedulers got removed, so the bug fixes to them in 'net' are irrelevant. A packet action unload crash fix conflicts with the addition of the new firstuse timestamp. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-08sched: remove qdisc->dropFlorian Westphal1-20/+0
after removal of TCA_CBQ_OVL_STRATEGY from cbq scheduler, there are no more callers of ->drop() outside of other ->drop functions, i.e. nothing calls them. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-03sch_red: update backlog as wellWANG Cong1-0/+4
Fixes: 2ccccf5fb43f ("net_sched: update hierarchical backlog too") Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-29net_sched: update hierarchical backlog tooWANG Cong1-1/+2
When the bottom qdisc decides to, for example, drop some packet, it calls qdisc_tree_decrease_qlen() to update the queue length for all its ancestors, we need to update the backlog too to keep the stats on root qdisc accurate. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-29net_sched: introduce qdisc_replace() helperWANG Cong1-6/+1
Remove nearly duplicated code and prepare for the following patch. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-30net: sched: implement qstat helper routinesJohn Fastabend1-4/+4
This adds helpers to manipulate qstats logic and replaces locations that touch the counters directly. This simplifies future patches to push qstats onto per cpu counters. Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-01pkt_sched: Stop using NLA_PUT*().David S. Miller1-2/+3
These macros contain a hidden goto, and are thus extremely error prone and make code hard to audit. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-05net_sched: red: split red_parms into parms and varsEric Dumazet1-12/+17
This patch splits the red_parms structure into two components. One holding the RED 'constant' parameters, and one containing the variables. This permits a size reduction of GRED qdisc, and is a preliminary step to add an optional RED unit to SFQ. SFQRED will have a single red_parms structure shared by all flows, and a private red_vars per flow. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Dave Taht <dave.taht@gmail.com> CC: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-09sch_red: generalize accurate MAX_P support to RED/GRED/CHOKEEric Dumazet1-2/+7
Now RED uses a Q0.32 number to store max_p (max probability), allow RED/GRED/CHOKE to use/report full resolution at config/dump time. Old tc binaries are non aware of new attributes, and still set/get Plog. New tc binary set/get both Plog and max_p for backward compatibility, they display "probability value" if they get max_p from new kernels. # tc -d qdisc show dev ... ... qdisc red 10: parent 1:1 limit 360Kb min 30Kb max 90Kb ecn ewma 5 probability 0.09 Scell_log 15 Make sure we avoid potential divides by 0 in reciprocal_value(), if (max_th - min_th) is big. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-08sch_red: Adaptative RED AQMEric Dumazet1-0/+21
Adaptative RED AQM for linux, based on paper from Sally FLoyd, Ramakrishna Gummadi, and Scott Shenker, August 2001 : http://icir.org/floyd/papers/adaptiveRed.pdf Goal of Adaptative RED is to make max_p a dynamic value between 1% and 50% to reach the target average queue : (max_th - min_th) / 2 Every 500 ms: if (avg > target and max_p <= 0.5) increase max_p : max_p += alpha; else if (avg < target and max_p >= 0.01) decrease max_p : max_p *= beta; target :[min_th + 0.4*(min_th - max_th), min_th + 0.6*(min_th - max_th)]. alpha : min(0.01, max_p / 4) beta : 0.9 max_P is a Q0.32 fixed point number (unsigned, with 32 bits mantissa) Changes against our RED implementation are : max_p is no longer a negative power of two (1/(2^Plog)), but a Q0.32 fixed point number, to allow full range described in Adatative paper. To deliver a random number, we now use a reciprocal divide (thats really a multiply), but this operation is done once per marked/droped packet when in RED_BETWEEN_TRESH window, so added cost (compared to previous AND operation) is near zero. dump operation gives current max_p value in a new TCA_RED_MAX_P attribute. Example on a 10Mbit link : tc qdisc add dev $DEV parent 1:1 handle 10: est 1sec 8sec red \ limit 400000 min 30000 max 90000 avpkt 1000 \ burst 55 ecn adaptative bandwidth 10Mbit # tc -s -d qdisc show dev eth3 ... qdisc red 10: parent 1:1 limit 400000b min 30000b max 90000b ecn adaptative ewma 5 max_p=0.113335 Scell_log 15 Sent 50414282 bytes 34504 pkt (dropped 35, overlimits 1392 requeues 0) rate 9749Kbit 831pps backlog 72056b 16p requeues 0 marked 1357 early 35 pdrop 0 other 0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-01sch_red: fix red_changeEric Dumazet1-2/+2
Le mercredi 30 novembre 2011 à 14:36 -0800, Stephen Hemminger a écrit : > (Almost) nobody uses RED because they can't figure it out. > According to Wikipedia, VJ says that: > "there are not one, but two bugs in classic RED." RED is useful for high throughput routers, I doubt many linux machines act as such devices. I was considering adding Adaptative RED (Sally Floyd, Ramakrishna Gummadi, Scott Shender), August 2001 In this version, maxp is dynamic (from 1% to 50%), and user only have to setup min_th (target average queue size) (max_th and wq (burst in linux RED) are automatically setup) By the way it seems we have a small bug in red_change() if (skb_queue_empty(&sch->q)) red_end_of_idle_period(&q->parms); First, if queue is empty, we should call red_start_of_idle_period(&q->parms); Second, since we dont use anymore sch->q, but q->qdisc, the test is meaningless. Oh well... [PATCH] sch_red: fix red_change() Now RED is classful, we must check q->qdisc->q.qlen, and if queue is empty, we start an idle period, not end it. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-24Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6David S. Miller1-5/+6
Conflicts: net/sched/sch_hfsc.c net/sched/sch_htb.c net/sched/sch_tbf.c
2011-01-20net_sched: accurate bytes/packets stats/ratesEric Dumazet1-5/+6
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 <eric.dumazet@gmail.com> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-19net_sched: cleanupsEric Dumazet1-31/+30
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>
2011-01-10net_sched: factorize qdisc stats handlingEric Dumazet1-2/+1
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 <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-03sch_red: report backlog informationEric Dumazet1-0/+1
Provide child qdisc backlog (byte count) information so that "tc -s qdisc" can report it to user. packet count is already correctly provided. qdisc red 11: parent 1:11 limit 60Kb min 15Kb max 45Kb ecn Sent 3116427684 bytes 1415782 pkt (dropped 8, overlimits 7866 requeues 0) rate 242385Kbit 13630pps backlog 13560b 8p requeues 0 marked 7865 early 1 pdrop 7 other 0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-17net: Remove unnecessary returns from void function()sJoe Perches1-1/+0
This patch removes from net/ (but not any netfilter files) all the unnecessary return; statements that precede the last closing brace of void functions. It does not remove the returns that are immediately preceded by a label as gcc doesn't like that. Done via: $ grep -rP --include=*.[ch] -l "return;\n}" net/ | \ xargs perl -i -e 'local $/ ; while (<>) { s/\n[ \t\n]+return;\n}/\n}/g; print; }' Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-06net_sched: remove some unnecessary checks in classful schedulersPatrick McHardy1-2/+0
The class argument to the ->graft(), ->leaf(), ->dump(), ->dump_stats() all originate from either ->get() or ->walk() and are always valid. Remove unnecessary checks. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-06net_sched: make cls_ops->change and cls_ops->delete optionalPatrick McHardy1-13/+0
Some schedulers don't support creating, changing or deleting classes. Make the respective callbacks optionally and consistently return -EOPNOTSUPP for unsupported operations, instead of currently either -EOPNOTSUPP, -ENOSYS or no error. In case of sch_prio and sch_multiq, the removed operations additionally checked for an invalid class. This is not necessary since the class argument can only orginate from ->get() or in case of ->change is 0 for creation of new classes, in which case ->change() incorrectly returned -ENOENT. As a side-effect, this patch fixes a possible (root-only) NULL pointer function call in sch_ingress, which didn't implement a so far mandatory ->delete() operation. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-06net_sched: make cls_ops->tcf_chain() optionalPatrick McHardy1-6/+0
Some qdiscs don't support attaching filters. Handle this centrally in cls_api and return a proper errno code (EOPNOTSUPP) instead of EINVAL. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-20pkt_sched: remove unnecessary xchg() in packet schedulersPatrick McHardy1-2/+4
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 <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-13pkt_sched: Remove qdisc->ops->requeue() etc.Jarek Poplawski1-18/+0
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>
2008-10-31pkt_sched: Add qdisc->ops->peek() implementation.Jarek Poplawski1-0/+9
Add qdisc->ops->peek() implementation for work-conserving qdiscs. With feedback from Patrick McHardy. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-04net_sched: Add qdisc __NET_XMIT_STOLEN flagJarek Poplawski1-1/+1
Patrick McHardy <kaber@trash.net> noticed: "The other problem that affects all qdiscs supporting actions is TC_ACT_QUEUED/TC_ACT_STOLEN getting mapped to NET_XMIT_SUCCESS even though the packet is not queued, corrupting upper qdiscs' qlen counters." and later explained: "The reason why it translates it at all seems to be to not increase the drops counter. Within a single qdisc this could be avoided by other means easily, upper qdiscs would still increase the counter when we return anything besides NET_XMIT_SUCCESS though. This means we need a new NET_XMIT return value to indicate this to the upper qdiscs. So I'd suggest to introduce NET_XMIT_STOLEN, return that to upper qdiscs and translate it to NET_XMIT_SUCCESS in dev_queue_xmit, similar to NET_XMIT_BYPASS." David Miller <davem@davemloft.net> noticed: "Maybe these NET_XMIT_* values being passed around should be a set of bits. They could be composed of base meanings, combined with specific attributes. So you could say "NET_XMIT_DROP | __NET_XMIT_NO_DROP_COUNT" The attributes get masked out by the top-level ->enqueue() caller, such that the base meanings are the only thing that make their way up into the stack. If it's only about communication within the qdisc tree, let's simply code it that way." This patch is trying to realize these ideas. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-20net_sched: Add accessor function for packet length for qdiscsJussi Kivilinna1-1/+1
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-20net_sched: Add qdisc_enqueue wrapperJussi Kivilinna1-1/+1
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
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