aboutsummaryrefslogtreecommitdiffstats
path: root/net/sched/sch_hfsc.c (unfollow)
AgeCommit message (Collapse)AuthorFilesLines
2019-04-27netlink: make validation more configurable for future strictnessJohannes Berg1-1/+2
We currently have two levels of strict validation: 1) liberal (default) - undefined (type >= max) & NLA_UNSPEC attributes accepted - attribute length >= expected accepted - garbage at end of message accepted 2) strict (opt-in) - NLA_UNSPEC attributes accepted - attribute length >= expected accepted Split out parsing strictness into four different options: * TRAILING - check that there's no trailing data after parsing attributes (in message or nested) * MAXTYPE - reject attrs > max known type * UNSPEC - reject attributes with NLA_UNSPEC policy entries * STRICT_ATTRS - strictly validate attribute size The default for future things should be *everything*. The current *_strict() is a combination of TRAILING and MAXTYPE, and is renamed to _deprecated_strict(). The current regular parsing has none of this, and is renamed to *_parse_deprecated(). Additionally it allows us to selectively set one of the new flags even on old policies. Notably, the UNSPEC flag could be useful in this case, since it can be arranged (by filling in the policy) to not be an incompatible userspace ABI change, but would then going forward prevent forgetting attribute entries. Similar can apply to the POLICY flag. We end up with the following renames: * nla_parse -> nla_parse_deprecated * nla_parse_strict -> nla_parse_deprecated_strict * nlmsg_parse -> nlmsg_parse_deprecated * nlmsg_parse_strict -> nlmsg_parse_deprecated_strict * nla_parse_nested -> nla_parse_nested_deprecated * nla_validate_nested -> nla_validate_nested_deprecated Using spatch, of course: @@ expression TB, MAX, HEAD, LEN, POL, EXT; @@ -nla_parse(TB, MAX, HEAD, LEN, POL, EXT) +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression TB, MAX, NLA, POL, EXT; @@ -nla_parse_nested(TB, MAX, NLA, POL, EXT) +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT) @@ expression START, MAX, POL, EXT; @@ -nla_validate_nested(START, MAX, POL, EXT) +nla_validate_nested_deprecated(START, MAX, POL, EXT) @@ expression NLH, HDRLEN, MAX, POL, EXT; @@ -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT) +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT) For this patch, don't actually add the strict, non-renamed versions yet so that it breaks compile if I get it wrong. Also, while at it, make nla_validate and nla_parse go down to a common __nla_validate_parse() function to avoid code duplication. Ultimately, this allows us to have very strict validation for every new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the next patch, while existing things will continue to work as is. In effect then, this adds fully strict validation for any new command. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-27netlink: make nla_nest_start() add NLA_F_NESTED flagMichal Kubecek1-1/+1
Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most netlink based interfaces (including recently added ones) are still not setting it in kernel generated messages. Without the flag, message parsers not aware of attribute semantics (e.g. wireshark dissector or libmnl's mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display the structure of their contents. Unfortunately we cannot just add the flag everywhere as there may be userspace applications which check nlattr::nla_type directly rather than through a helper masking out the flags. Therefore the patch renames nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start() as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually are rewritten to use nla_nest_start(). Except for changes in include/net/netlink.h, the patch was generated using this semantic patch: @@ expression E1, E2; @@ -nla_nest_start(E1, E2) +nla_nest_start_noflag(E1, E2) @@ expression E1, E2; @@ -nla_nest_start_noflag(E1, E2 | NLA_F_NESTED) +nla_nest_start(E1, E2) Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Acked-by: Jiri Pirko <jiri@mellanox.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-01net: sched: introduce and use qdisc tree flush/purge helpersPaolo Abeni1-12/+2
The same code to flush qdisc tree and purge the qdisc queue is duplicated in many places and in most cases it does not respect NOLOCK qdisc: the global backlog len is used and the per CPU values are ignored. This change addresses the above, factoring-out the relevant code and using the helpers introduced by the previous patch to fetch the correct backlog len. Fixes: c5ad119fb6c0 ("net: sched: pfifo_fast use skb_array") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-01net: sched: introduce and use qstats read helpersPaolo Abeni1-2/+3
Classful qdiscs can't access directly the child qdiscs backlog length: if such qdisc is NOLOCK, per CPU values should be accounted instead. Most qdiscs no not respect the above. As a result, qstats fetching for most classful qdisc is currently incorrect: if the child qdisc is NOLOCK, it always reports 0 len backlog. This change introduces a pair of helpers to safely fetch both backlog and qlen and use them in stats class dumping functions, fixing the above issue and cleaning a bit the code. DRR needs also to access the child qdisc queue length, so it needs custom handling. Fixes: c5ad119fb6c0 ("net: sched: pfifo_fast use skb_array") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-15sched: Fix detection of empty queues in child qdiscsToke Høiland-Jørgensen1-1/+3
Several qdiscs check on enqueue whether the packet was enqueued to a class with an empty queue, in which case the class is activated. This is done by checking if the qlen is exactly 1 after enqueue. However, if GSO splitting is enabled in the child qdisc, a single packet can result in a qlen longer than 1. This means the activation check fails, leading to a stalled queue. Fix this by checking if the queue is empty *before* enqueue, and running the activation logic if this was the case. Reported-by: Pete Heist <pete@heistp.net> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-15sched: Avoid dereferencing skb pointer after child enqueueToke Høiland-Jørgensen1-3/+2
Parent qdiscs may dereference the pointer to the enqueued skb after enqueue. However, both CAKE and TBF call consume_skb() on the original skb when splitting GSO packets, leading to a potential use-after-free in the parent. Fix this by avoiding dereferencing the skb pointer after enqueueing to the child. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-25net: sched: rename qdisc_destroy() to qdisc_put()Vlad Buslov1-1/+1
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>
2018-06-23net_sched: remove a bogus warning in hfscCong Wang1-2/+2
In update_vf(): cftree_remove(cl); update_cfmin(cl->cl_parent); the cl_cfmin of cl->cl_parent is intentionally updated to 0 when that parent only has one child. And if this parent is root qdisc, we could end up, in hfsc_schedule_watchdog(), that we can't decide the next schedule time for qdisc watchdog. But it seems safe that we can just skip it, as this watchdog is not always scheduled anyway. Thanks to Marco for testing all the cases, nothing is broken. Reported-by: Marco Berizzi <pupilla@libero.it> Tested-by: Marco Berizzi <pupilla@libero.it> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-21net: sch: api: add extack support in qdisc_create_dfltAlexander Aring1-4/+4
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: sch: api: add extack support in tcf_block_getAlexander Aring1-2/+2
This patch adds extack support for the function tcf_block_get 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 tcf_block_get failed. 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 block callbackAlexander Aring1-1/+2
This patch adds extack support for block 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 to change classAlexander Aring1-1/+2
This patch adds extack support for class change callback api. This prepares to handle extack support inside each specific class implementation. 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 Aring1-1/+2
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>
2017-12-21net: sched: fix coding style issuesAlexander Aring1-1/+1
This patch fix checkpatch issues for upcomming patches according to the sched api file. It changes mostly how to check on null pointer. 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>
2017-10-22net: sched: mark expected switch fall-throughsGustavo A. R. Silva1-0/+1
In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-16net: sched: store Qdisc pointer in struct blockJiri Pirko1-2/+2
Prepare for removal of tp->q and store Qdisc pointer in the block structure. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-21net_sched/hfsc: fix curve activation in hfsc_change_class()Konstantin Khlebnikov1-4/+19
If real-time or fair-share curves are enabled in hfsc_change_class() class isn't inserted into rb-trees yet. Thus init_ed() and init_vf() must be called in place of update_ed() and update_vf(). Remove isn't required because for now curves cannot be disabled. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-30sch_hfsc: fix null pointer deref and double free on init failureNikolay Aleksandrov1-7/+3
Depending on where ->init fails we can get a null pointer deref due to uninitialized hires timer (watchdog) or a double free of the qdisc hash because it is already freed by ->destroy(). Fixes: 8d5537387505 ("net/sched/hfsc: allocate tcf block for hfsc root class") Fixes: 87b60cfacf9f ("net_sched: fix error recovery at qdisc creation") Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25net_sched: remove tc class reference countingWANG Cong1-27/+5
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>
2017-08-16net_sched/hfsc: opencode trivial set_active() and set_passive()Konstantin Khlebnikov1-29/+16
Any move comment abount update_vf() into right place. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-16net_sched: call qlen_notify only if child qdisc is emptyKonstantin Khlebnikov1-4/+2
This callback is used for deactivating class in parent qdisc. This is cheaper to test queue length right here. Also this allows to catch draining screwed backlog and prevent second deactivation of already inactive parent class which will crash kernel for sure. Kernel with print warning at destruction of child qdisc where no packets but backlog is not zero. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-15net_sched: reset pointers to tcf blocks in classful qdiscs' destructorsKonstantin Khlebnikov1-1/+3
Traffic filters could keep direct pointers to classes in classful qdisc, thus qdisc destruction first removes all filters before freeing classes. Class destruction methods also tries to free attached filters but now this isn't safe because tcf_block_put() unlike to tcf_destroy_chain() cannot be called second time. This patch set class->block to NULL after first tcf_block_put() and turn second call into no-op. Fixes: 6529eaba33f0 ("net: sched: introduce tcf block infractructure") Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-11net/sched/hfsc: allocate tcf block for hfsc root classKonstantin Khlebnikov1-0/+8
Without this filters cannot be attached. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Fixes: 6529eaba33f0 ("net: sched: introduce tcf block infractructure") Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-06net: sched: introduce a TRAP control actionJiri Pirko1-0/+1
There is need to instruct the HW offloaded path to push certain matched packets to cpu/kernel for further analysis. So this patch introduces a new TRAP control action to TC. For kernel datapath, this action does not make much sense. So with the same logic as in HW, new TRAP behaves similar to STOLEN. The skb is just dropped in the datapath (and virtually ejected to an upper level, which does not exist in case of kernel). Signed-off-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Yotam Gigi <yotamg@mellanox.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-17net: sched: introduce tcf block infractructureJiri Pirko1-6/+13
Currently, the filter chains are direcly put into the private structures of qdiscs. In order to be able to have multiple chains per qdisc and to allow filter chains sharing among qdiscs, there is a need for common object that would hold the chains. This introduces such object and calls it "tcf_block". Helpers to get and put the blocks are provided to be called from individual qdisc code. Also, the original filter_list pointers are left in qdisc privs to allow the entry into tcf_block processing without any added overhead of possible multiple pointer dereference on fast path. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-17net: sched: move tc_classify function to cls_api.cJiri Pirko1-1/+1
Move tc_classify function to cls_api.c where it belongs, rename it to fit the namespace. Signed-off-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/+4
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>
2016-12-05net_sched: gen_estimator: complete rewrite of rate estimatorsEric Dumazet1-3/+3
1) Old code was hard to maintain, due to complex lock chains. (We probably will be able to remove some kfree_rcu() in callers) 2) Using a single timer to update all estimators does not scale. 3) Code was buggy on 32bit kernel (WRITE_ONCE() on 64bit quantity is not supposed to work well) In this rewrite : - I removed the RB tree that had to be scanned in gen_estimator_active(). qdisc dumps should be much faster. - Each estimator has its own timer. - Estimations are maintained in net_rate_estimator structure, instead of dirtying the qdisc. Minor, but part of the simplification. - Reading the estimator uses RCU and a seqcount to provide proper support for 32bit kernels. - We reduce memory need when estimators are not used, since we store a pointer, instead of the bytes/packets counters. - xt_rateest_mt() no longer has to grab a spinlock. (In the future, xt_rateest_tg() could be switched to per cpu counters) Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-08net/sched/sch_hfsc.c: remove unused cl_myfadjMichal Soltys1-5/+2
The code using this variable has been commented out in the past as it was causing issues in upperlimited link-sharing scenarios. Signed-off-by: Michal Soltys <soltys@ziu.info> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-08net/sched/sch_hfsc.c: keep fsc and virtual times in sync; fix an old bugMichal Soltys1-32/+12
This patch simplifies how we update fsc and calculate vt from it - while keeping the expected functionality identical with how hfsc behaves curently. It also fixes a certain issue introduced with a very old patch. The idea is, that instead of correcting cl_vt before fsc curve update (rtsc_min) and correcting cl_vt after calculation (rtsc_y2x) to keep cl_vt local to the current period - we can simply rely on virtual times and curve values always being in sync - analogously to how rsc and usc function, except that we use virtual time here. Why hasn't it been done since the beginning this way ? The likely scenario (basing on the code trying to correct curves whenever possible) was to keep the virtual times as small as possible - as they have tendency to "gallop" forward whenever their siblings and other fair sharing subtrees are idling. On top of that, current code is subtly bugged, so cumulative time (without any corrections) is always kept and used in init_vf() when a new backlog period begins (using cl_cvtoff). Is cumulative value safe ? Generally yes, though corner cases are easy to create. For example consider: 1gbit interface some 100kbit leaf, everything else idle With current tick (64ns) 1s is 15625000 ticks, but the leaf is alone and it's virtual time, so in reality it's 10000 times more. ITOW 38 bits are needed to hold 1 second. 54 - 1 day, 59 - 1 month, 63 - 1 year (all logarithms rounded up). It's getting somewhat dangerous, but also requires setup excusing this kind of values not mentioning permanently backlogged class for a year. In near most extreme case (10gbit, 10kbit leaf), we have "enough" to hold ~13.6 days in 64 bits. Well, the issue remains mostly theoretical and cl_cvtoff has been working fine for all those years. Sensible configuration are de-facto immune to this issue, and not so sensible can solve it with a cronjob and its period inversely proportional to the insanity of such setup =) Now let's explain the subtle bug mentioned earlier. The issue is related to how offsets are kept and how we calculate virtual times and update fair service curve(s). The issue itself is subtle, but easy to observe with long m1 segments. It was introduced in rather old patch: Commit 99296150c7: "[NET_SCHED]: O(1) children vtoff adjustment in HFSC scheduler" (available in git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git) Originally when a new backlog period was started, cl_vtoff of each sibling was updated with cl_cvtmax from past period - naturally moving all cl_vt to proper starting point. That patch adjusted it so cumulative offset is kept in the parent, and there is no need for traversing the list (as any subsequent child activation derives new vt from already active sibling(s)). But with this change, cl_vtoff (of each sibling) is no longer persistent across the inactivity periods, as it's calculated from parent's cl_cvtoff on a new backlog period, conflicting with the following curve correction from the previous period: if (cl->cl_virtual.x == vt) { cl->cl_virtual.x -= cl->cl_vtoff; cl->cl_vtoff = 0; } This essentially tries to keep curve as if it was local to the period and resets cl_vtoff (cumulative vt offset of the class) to 0 when possible (read: when we have an intersection or if a new curve is below the old one). But then it's recalculated from cl_cvtoff on next active period. Then rtsc_min() call preceding the above if() doesn't really do what we expect it to do in such scenario - as it calculates the minimum of corrected curve (from the previous backlog period) and the new uncorrected curve (with offset derived from cl_cvtoff). Example: tc class add dev $ife parent 1:0 classid 1:1 hfsc ls m2 100mbit ul m2 100mbit tc class add dev $ife parent 1:1 classid 1:10 hfsc ls m1 80mbit d 10s m2 20mbit tc class add dev $ife parent 1:1 classid 1:11 hfsc ls m2 20mbit start B, keep it backlogged, let it run 6s (30s worth of vt as A is idle) pause B briefly to force cl_cvtoff update in parent (whole 1:1 going idle) start A, let it run 10s pause A briefly to force rtsc_min() At this point we would expect A to continue at 20mbit after a brief moment of 80mbit. But instead A will use 80mbit for full 10s again. It's the effect of first correcting A (during 'start A'), and then - after unpausing - calculating rtsc_min() from old corrected and new uncorrected curve. The patch fixes this bug and keepis vt and fsc in sync (virtual times are cumulative, not local to the backlog period). Signed-off-by: Michal Soltys <soltys@ziu.info> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-08hfsc: reduce hfsc_sched to 14 cachelinesFlorian Westphal1-5/+5
hfsc_sched is huge (size: 920, cachelines: 15), but we can get it to 14 cachelines by placing level after filter_cnt (covering 4 byte hole) and reducing period/nactive/flags to u32 (period is just a counter, incremented when class becomes active -- 2**32 is plenty for this purpose, also, long is only 32bit wide on 32bit platforms anyway). cl_vtperiod is exported to userspace via tc_hfsc_stats, but its period member is already u32, so no precision is lost there either. Cc: Michal Soltys <soltys@ziu.info> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-01net/sched/sch_hfsc.c: anchor virtual curve at proper vt in hfsc_change_fsc()Michal Soltys1-1/+1
cl->cl_vt alone is relative only to the current backlog period, while the curve operates on cumulative virtual time. This patch adds missing cl->cl_vtoff. Signed-off-by: Michal Soltys <soltys@ziu.info> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-01net/sched/sch_hfsc.c: go passive after vt updateMichal Soltys1-16/+15
When a class is going passive, it should update its cl_vt first to be consistent with the last dequeue operation. Otherwise its cl_vt will be one packet behind and parent's cvtmax might not be updated as well. One possible side effect is if some class goes passive and subsequently goes active /without/ its parent going passive - with cl_vt lagging one packet behind - comparison made in init_vf() will be affected (same period). Signed-off-by: Michal Soltys <soltys@ziu.info> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-01net/sched/sch_hfsc.c: remove leftover dlist and droplistMichal Soltys1-8/+0
This is update to: commit a09ceb0e08140a ("sched: remove qdisc->drop") That commit removed qdisc->drop, but left alone dlist and droplist that no longer serve any meaningful purpose. Signed-off-by: Michal Soltys <soltys@ziu.info> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-01net/sched/sch_hfsc.c: add unlikely() in qdisc_peek_len()Michal Soltys1-1/+1
The condition can only succeed on wrong configurations. Signed-off-by: Michal Soltys <soltys@ziu.info> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-01net/sched/sch_hfsc.c: handle corner cases where head may change invalidating calculated deadlineMichal Soltys1-1/+10
Realtime scheduling implemented in HFSC uses head of the queue to make the decision about which packet to schedule next. But in case of any head drop, the deadline calculated for the previous head is not necessarily correct for the next head (unless both packets have the same length). Thanks to peek() function used during dequeue - which internally is a dequeue operation - hfsc is almost safe from this issue, as peek() dequeues and isolates the head storing it temporarily until the real dequeue happens. But there is one exception: if after the class activation a drop happens before the first dequeue operation, there's never a chance to do the peek(). Adding peek() call in enqueue - if this is the first packet in a new backlog period AND the scheduler has realtime curve defined - fixes that one corner case. The 1st hfsc_dequeue() will use that peeked packet, similarly as every subsequent hfsc_dequeue() call uses packet peeked by the previous call. Signed-off-by: Michal Soltys <soltys@ziu.info> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-25net_sched: drop packets after root qdisc lock is releasedEric Dumazet1-3/+3
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>
2016-06-10net_sched: remove generic throttled managementEric Dumazet1-1/+0
__QDISC_STATE_THROTTLED bit manipulation is rather expensive for HTB and few others. I already removed it for sch_fq in commit f2600cf02b5b ("net: sched: avoid costly atomic operation in fq_dequeue()") and so far nobody complained. When one ore more packets are stuck in one or more throttled HTB class, a htb dequeue() performs two atomic operations to clear/set __QDISC_STATE_THROTTLED bit, while root qdisc lock is held. Removing this pair of atomic operations bring me a 8 % performance increase on 200 TCP_RR tests, in presence of throttled classes. This patch has no side effect, since nothing actually uses disc_is_throttled() anymore. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-08sched: remove qdisc->dropFlorian Westphal1-26/+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>
2016-06-07net: sched: do not acquire qdisc spinlock in qdisc/class stats dumpEric Dumazet1-5/+5
Large tc dumps (tc -s {qdisc|class} sh dev ethX) done by Google BwE host agent [1] are problematic at scale : For each qdisc/class found in the dump, we currently lock the root qdisc spinlock in order to get stats. Sampling stats every 5 seconds from thousands of HTB classes is a challenge when the root qdisc spinlock is under high pressure. Not only the dumps take time, they also slow down the fast path (queue/dequeue packets) by 10 % to 20 % in some cases. An audit of existing qdiscs showed that sch_fq_codel is the only qdisc that might need the qdisc lock in fq_codel_dump_stats() and fq_codel_dump_class_stats() In v2 of this patch, I now use the Qdisc running seqcount to provide consistent reads of packets/bytes counters, regardless of 32/64 bit arches. I also changed rate estimators to use the same infrastructure so that they no longer need to lock root qdisc lock. [1] http://static.googleusercontent.com/media/research.google.com/en//pubs/archive/43838.pdf Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Kevin Athey <kda@google.com> Cc: Xiaotian Pei <xiaotian@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-03sch_hfsc: always keep backlog updatedWANG Cong1-8/+4
hfsc updates backlog lazily, that is only when we dump the stats. This is problematic after we begin to update backlog in qdisc_tree_reduce_backlog(). Reported-by: Stas Nichiporovich <stasn77@gmail.com> Tested-by: Stas Nichiporovich <stasn77@gmail.com> 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 Cong1-5/+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>
2015-08-27net: sched: consolidate tc_classify{,_compat}Daniel Borkmann1-1/+1
For classifiers getting invoked via tc_classify(), we always need an extra function call into tc_classify_compat(), as both are being exported as symbols and tc_classify() itself doesn't do much except handling of reclassifications when tp->classify() returned with TC_ACT_RECLASSIFY. CBQ and ATM are the only qdiscs that directly call into tc_classify_compat(), all others use tc_classify(). When tc actions are being configured out in the kernel, tc_classify() effectively does nothing besides delegating. We could spare this layer and consolidate both functions. pktgen on single CPU constantly pushing skbs directly into the netif_receive_skb() path with a dummy classifier on ingress qdisc attached, improves slightly from 22.3Mpps to 23.1Mpps. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-30net: sched: enable per cpu qstatsJohn Fastabend1-1/+1
After previous patches to simplify qstats the qstats can be made per cpu with a packed union in Qdisc struct. Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-30net: sched: restrict use of qstats qlenJohn Fastabend1-2/+1
This removes the use of qstats->qlen variable from the classifiers and makes it an explicit argument to gnet_stats_copy_queue(). The qlen represents the qdisc queue length and is packed into the qstats at the last moment before passnig to user space. By handling it explicitely we avoid, in the percpu stats case, having to figure out which per_cpu variable to put it in. It would probably be best to remove it from qstats completely but qstats is a user space ABI and can't be broken. A future patch could make an internal only qstats structure that would avoid having to allocate an additional u32 variable on the Qdisc struct. This would make the qstats struct 128bits instead of 128+32. Signed-off-by: John Fastabend <john.r.fastabend@intel.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>