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* net: sched: Remove Qdisc::running sequence counterAhmed S. Darwish2021-10-181-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Qdisc::running sequence counter has two uses: 1. Reliably reading qdisc's tc statistics while the qdisc is running (a seqcount read/retry loop at gnet_stats_add_basic()). 2. As a flag, indicating whether the qdisc in question is running (without any retry loops). For the first usage, the Qdisc::running sequence counter write section, qdisc_run_begin() => qdisc_run_end(), covers a much wider area than what is actually needed: the raw qdisc's bstats update. A u64_stats sync point was thus introduced (in previous commits) inside the bstats structure itself. A local u64_stats write section is then started and stopped for the bstats updates. Use that u64_stats sync point mechanism for the bstats read/retry loop at gnet_stats_add_basic(). For the second qdisc->running usage, a __QDISC_STATE_RUNNING bit flag, accessed with atomic bitops, is sufficient. Using a bit flag instead of a sequence counter at qdisc_run_begin/end() and qdisc_is_running() leads to the SMP barriers implicitly added through raw_read_seqcount() and write_seqcount_begin/end() getting removed. All call sites have been surveyed though, and no required ordering was identified. Now that the qdisc->running sequence counter is no longer used, remove it. Note, using u64_stats implies no sequence counter protection for 64-bit architectures. This can lead to the qdisc tc statistics "packets" vs. "bytes" values getting out of sync on rare occasions. The individual values will still be valid. Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: sched: Merge Qdisc::bstats and Qdisc::cpu_bstats data typesAhmed S. Darwish2021-10-181-3/+3
| | | | | | | | | | | | | | | | | | | The only factor differentiating per-CPU bstats data type (struct gnet_stats_basic_cpu) from the packed non-per-CPU one (struct gnet_stats_basic_packed) was a u64_stats sync point inside the former. The two data types are now equivalent: earlier commits added a u64_stats sync point to the latter. Combine both data types into "struct gnet_stats_basic_sync". This eliminates redundancy and simplifies the bstats read/write APIs. Use u64_stats_t for bstats "packets" and "bytes" data types. On 64-bit architectures, u64_stats sync points do not use sequence counter protection. Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: sched: Protect Qdisc::bstats with u64_statsAhmed S. Darwish2021-10-181-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The not-per-CPU variant of qdisc tc (traffic control) statistics, Qdisc::gnet_stats_basic_packed bstats, is protected with Qdisc::running sequence counter. This sequence counter is used for reliably protecting bstats reads from parallel writes. Meanwhile, the seqcount's write section covers a much wider area than bstats update: qdisc_run_begin() => qdisc_run_end(). That read/write section asymmetry can lead to needless retries of the read section. To prepare for removing the Qdisc::running sequence counter altogether, introduce a u64_stats sync point inside bstats instead. Modify _bstats_update() to start/end the bstats u64_stats write section. For bisectability, and finer commits granularity, the bstats read section is still protected with a Qdisc::running read/retry loop and qdisc_run_begin/end() still starts/ends that seqcount write section. Once all call sites are modified to use _bstats_update(), the Qdisc::running seqcount will be removed and bstats read/retry loop will be modified to utilize the internal u64_stats sync point. Note, using u64_stats implies no sequence counter protection for 64-bit architectures. This can lead to the statistics "packets" vs. "bytes" values getting out of sync on rare occasions. The individual values will still be valid. [bigeasy: Minor commit message edits, init all gnet_stats_basic_packed.] Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
* mq, mqprio: Use gnet_stats_add_queue().Sebastian Andrzej Siewior2021-10-181-38/+13
| | | | | | | | | | | | | | | | | gnet_stats_add_basic() and gnet_stats_add_queue() add up the statistics so they can be used directly for both the per-CPU and global case. gnet_stats_add_queue() copies either Qdisc's per-CPU gnet_stats_queue::qlen or the global member. The global gnet_stats_queue::qlen isn't touched in the per-CPU case so there is no need to consider it in the global-case. In the per-CPU case, the sum of global gnet_stats_queue::qlen and the per-CPU gnet_stats_queue::qlen was assigned to sch->q.qlen and sch->qstats.qlen. Now both fields are copied individually. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
* gen_stats: Add instead Set the value in __gnet_stats_copy_basic().Sebastian Andrzej Siewior2021-10-181-6/+5
| | | | | | | | | | | | | | | | | | | | | __gnet_stats_copy_basic() always assigns the value to the bstats argument overwriting the previous value. The later added per-CPU version always accumulated the values in the returning gnet_stats_basic_packed argument. Based on review there are five users of that function as of today: - est_fetch_counters(), ___gnet_stats_copy_basic() memsets() bstats to zero, single invocation. - mq_dump(), mqprio_dump(), mqprio_dump_class_stats() memsets() bstats to zero, multiple invocation but does not use the function due to !qdisc_is_percpu_stats(). Add the values in __gnet_stats_copy_basic() instead overwriting. Rename the function to gnet_stats_add_basic() to make it more obvious. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2021-10-141-12/+18
|\ | | | | | | | | | | | | | | tools/testing/selftests/net/ioam6.sh 7b1700e009cc ("selftests: net: modify IOAM tests for undef bits") bf77b1400a56 ("selftests: net: Test for the IOAM encapsulation with IPv6") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * mqprio: Correct stats in mqprio_dump_class_stats().Sebastian Andrzej Siewior2021-10-081-12/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduction of lockless subqueues broke the class statistics. Before the change stats were accumulated in `bstats' and `qstats' on the stack which was then copied to struct gnet_dump. After the change the `bstats' and `qstats' are initialized to 0 and never updated, yet still fed to gnet_dump. The code updates the global qdisc->cpu_bstats and qdisc->cpu_qstats instead, clobbering them. Most likely a copy-paste error from the code in mqprio_dump(). __gnet_stats_copy_basic() and __gnet_stats_copy_queue() accumulate the values for per-CPU case but for global stats they overwrite the value, so only stats from the last loop iteration / tc end up in sch->[bq]stats. Use the on-stack [bq]stats variables again and add the stats manually in the global case. Fixes: ce679e8df7ed2 ("net: sched: add support for TCQ_F_NOLOCK subqueues to sch_mqprio") Cc: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> https://lore.kernel.org/all/20211007175000.2334713-2-bigeasy@linutronix.de/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* | net: sched: move and reuse mq_change_real_num_tx()Jakub Kicinski2021-09-191-23/+1
| | | | | | | | | | | | | | | | | | The code for handling active queue changes is identical between mq and mqprio, reuse it. Suggested-by: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: sched: update default qdisc visibility after Tx queue cnt changesJakub Kicinski2021-09-151-0/+23
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | mq / mqprio make the default child qdiscs visible. They only do so for the qdiscs which are within real_num_tx_queues when the device is registered. Depending on order of calls in the driver, or if user space changes config via ethtool -L the number of qdiscs visible under tc qdisc show will differ from the number of queues. This is confusing to users and potentially to system configuration scripts which try to make sure qdiscs have the right parameters. Add a new Qdisc_ops callback and make relevant qdiscs TTRT. Note that this uncovers the "shortcut" created by commit 1f27cde313d7 ("net: sched: use pfifo_fast for non real queues") The default child qdiscs beyond initial real_num_tx are always pfifo_fast, no matter what the sysfs setting is. Fixing this gets a little tricky because we'd need to keep a reference on whatever the default qdisc was at the time of creation. In practice this is likely an non-issue the qdiscs likely have to be configured to non-default settings, so whatever user space is doing such configuration can replace the pfifos... now that it will see them. Reported-by: Matthew Massey <matthewmassey@fb.com> Reviewed-by: Dave Taht <dave.taht@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* mqprio: Fix out-of-bounds access in mqprio_dumpVladyslav Tarasiuk2019-12-061-1/+1
| | | | | | | | | | | | | | | | | | | | When user runs a command like tc qdisc add dev eth1 root mqprio KASAN stack-out-of-bounds warning is emitted. Currently, NLA_ALIGN macro used in mqprio_dump provides too large buffer size as argument for nla_put and memcpy down the call stack. The flow looks like this: 1. nla_put expects exact object size as an argument; 2. Later it provides this size to memcpy; 3. To calculate correct padding for SKB, nla_put applies NLA_ALIGN macro itself. Therefore, NLA_ALIGN should not be applied to the nla_put parameter. Otherwise it will lead to out-of-bounds memory access in memcpy. Fixes: 4e8b86c06269 ("mqprio: Introduce new hardware offload mode and shaper in mqprio") Signed-off-by: Vladyslav Tarasiuk <vladyslavt@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: sched: fix dump qlen for sch_mq/sch_mqprio with NOLOCK subqueuesDust Li2019-12-031-0/+1
| | | | | | | | | | sch->q.len hasn't been set if the subqueue is a NOLOCK qdisc in mq_dump() and mqprio_dump(). Fixes: ce679e8df7ed ("net: sched: add support for TCQ_F_NOLOCK subqueues to sch_mqprio") Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: sched: fix `tc -s class show` no bstats on class with nolock subqueuesDust Li2019-11-301-2/+2
| | | | | | | | | | | | | | | | | | | | | | When a classful qdisc's child qdisc has set the flag TCQ_F_CPUSTATS (pfifo_fast for example), the child qdisc's cpu_bstats should be passed to gnet_stats_copy_basic(), but many classful qdisc didn't do that. As a result, `tc -s class show dev DEV` always return 0 for bytes and packets in this case. Pass the child qdisc's cpu_bstats to gnet_stats_copy_basic() to fix this issue. The qstats also has this problem, but it has been fixed in 5dd431b6b9 ("net: sched: introduce and use qstats read...") and bstats still remains buggy. Fixes: 22e0f8b9322c ("net: sched: make bstats per cpu and estimator RCU safe") Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner2019-06-191-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* netlink: make validation more configurable for future strictnessJohannes Berg2019-04-271-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* netlink: make nla_nest_start() add NLA_F_NESTED flagMichal Kubecek2019-04-271-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* net: sched: introduce and use qstats read helpersPaolo Abeni2019-04-011-2/+1
| | | | | | | | | | | | | | | | | | | | | 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>
* net: sched: rename qdisc_destroy() to qdisc_put()Vlad Buslov2018-09-251-2/+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>
* net: sch: api: add extack support in qdisc_create_dfltAlexander Aring2017-12-211-1/+1
| | | | | | | | | | | | | | 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>
* net: sched: sch: add extack for graft callbackAlexander Aring2017-12-211-1/+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>
* net: sched: sch: add extack for init callbackAlexander Aring2017-12-211-1/+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>
* net: sched: add support for TCQ_F_NOLOCK subqueues to sch_mqprioJohn Fastabend2017-12-081-22/+47
| | | | | | | | | | | | | The sch_mqprio qdisc creates a sub-qdisc per tx queue which are then called independently for enqueue and dequeue operations. However statistics are aggregated and pushed up to the "master" qdisc. This patch adds support for any of the sub-qdiscs to be per cpu statistic qdiscs. To handle this case add a check when calculating stats and aggregate the per cpu stats if needed. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net_sch: mqprio: Change TC_SETUP_MQPRIO to TC_SETUP_QDISC_MQPRIONogah Frankel2017-11-081-2/+3
| | | | | | | | | | Change TC_SETUP_MQPRIO to TC_SETUP_QDISC_MQPRIO to match the new convention. 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>
* net/sched: Add select_queue() class_ops for mqprioJesus Sanchez-Palencia2017-10-271-0/+7
| | | | | | | | | | | | | | | | | When replacing a child qdisc from mqprio, tc_modify_qdisc() must fetch the netdev_queue pointer that the current child qdisc is associated with before creating the new qdisc. Currently, when using mqprio as root qdisc, the kernel will end up getting the queue #0 pointer from the mqprio (root qdisc), which leaves any new child qdisc with a possibly wrong netdev_queue pointer. Implementing the Qdisc_class_ops select_queue() on mqprio fixes this issue and avoid an inconsistent state when child qdiscs are replaced. Signed-off-by: Jesus Sanchez-Palencia <jesus.sanchez-palencia@intel.com> Tested-by: Henrik Austad <henrik@austad.us> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
* mqprio: fix potential null pointer dereference on optColin Ian King2017-10-191-1/+2
| | | | | | | | | | | | | The pointer opt has a null check however before for this check opt is dereferenced when len is initialized, hence we potentially have a null pointer deference on opt. Avoid this by checking for a null opt before dereferencing it. Detected by CoverityScan, CID#1458234 ("Dereference before null check") Fixes: 4e8b86c06269 ("mqprio: Introduce new hardware offload mode and shaper in mqprio") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* mqprio: Reserve last 32 classid values for HW traffic classes and misc IDsAlexander Duyck2017-10-161-33/+46
| | | | | | | | | | | | | | | | | | | | This patch makes a slight tweak to mqprio in order to bring the classid values used back in line with what is used for mq. The general idea is to reserve values :ffe0 - :ffef to identify hardware traffic classes normally reported via dev->num_tc. By doing this we can maintain a consistent behavior with mq for classid where :1 - :ffdf will represent a physical qdisc mapped onto a Tx queue represented by classid - 1, and the traffic classes will be mapped onto a known subset of classid values reserved for our virtual qdiscs. Note I reserved the range from :fff0 - :ffff since this way we might be able to reuse these classid values with clsact and ingress which would mean that for mq, mqprio, ingress, and clsact we should be able to maintain a similar classid layout. Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Tested-by: Jesus Sanchez-Palencia <jesus.sanchez-palencia@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* mqprio: Introduce new hardware offload mode and shaper in mqprioAmritha Nambiar2017-10-131-9/+174
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The offload types currently supported in mqprio are 0 (no offload) and 1 (offload only TCs) by setting these values for the 'hw' option. If offloads are supported by setting the 'hw' option to 1, the default offload mode is 'dcb' where only the TC values are offloaded to the device. This patch introduces a new hardware offload mode called 'channel' with 'hw' set to 1 in mqprio which makes full use of the mqprio options, the TCs, the queue configurations and the QoS parameters for the TCs. This is achieved through a new netlink attribute for the 'mode' option which takes values such as 'dcb' (default) and 'channel'. The 'channel' mode also supports QoS attributes for traffic class such as minimum and maximum values for bandwidth rate limits. This patch enables configuring additional HW shaper attributes associated with a traffic class. Currently the shaper for bandwidth rate limiting is supported which takes options such as minimum and maximum bandwidth rates and are offloaded to the hardware in the 'channel' mode. The min and max limits for bandwidth rates are provided by the user along with the TCs and the queue configurations when creating the mqprio qdisc. The interface can be extended to support new HW shapers in future through the 'shaper' attribute. Introduces a new data structure 'tc_mqprio_qopt_offload' for offloading mqprio queue options and use this to be shared between the kernel and device driver. This contains a copy of the existing data structure for mqprio queue options. This new data structure can be extended when adding new attributes for traffic class such as mode, shaper, shaper parameters (bandwidth rate limits). The existing data structure for mqprio queue options will be shared between the kernel and userspace. Example: queues 4@0 4@4 hw 1 mode channel shaper bw_rlimit\ min_rate 1Gbit 2Gbit max_rate 4Gbit 5Gbit To dump the bandwidth rates: qdisc mqprio 804a: root tc 2 map 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 queues:(0:3) (4:7) mode:channel shaper:bw_rlimit min_rate:1Gbit 2Gbit max_rate:4Gbit 5Gbit Signed-off-by: Amritha Nambiar <amritha.nambiar@intel.com> Tested-by: Andrew Bowers <andrewx.bowers@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
* net_sched: remove tc class reference countingWANG Cong2017-08-251-7/+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>
* net: sched: get rid of struct tc_to_netdevJiri Pirko2017-08-071-7/+6
| | | | | | | | | | | Get rid of struct tc_to_netdev which is now just unnecessary container and rather pass per-type structures down to drivers directly. Along with that, consolidate the naming of per-type structure variables in cls_*. 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>
* net: sched: push cls related args into cls_common structureJiri Pirko2017-08-071-4/+2
| | | | | | | | | | As ndo_setup_tc is generic offload op for whole tc subsystem, does not really make sense to have cls-specific args. So move them under cls_common structurure which is embedded in all cls structs. 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>
* net: sched: make type an argument for ndo_setup_tcJiri Pirko2017-08-071-7/+6
| | | | | | | | | Since the type is always present, push it to be a separate argument to ndo_setup_tc. On the way, name the type enum and use it for arg type. 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>
* net: propagate tc filter chain index down the ndo_setup_tc callJiri Pirko2017-06-081-2/+3
| | | | | | | | | | | We need to push the chain index down to the drivers, so they have the information to which chain the rule belongs. For now, no driver supports multichain offload, so only chain 0 is supported. This is needed to prevent chain squashes during offload for now. Later this will be used to implement multichain offload. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* mqprio: Modify mqprio to pass user parameters via ndo_setup_tc.Amritha Nambiar2017-03-151-6/+11
| | | | | | | | | | | | | | | | | | | | | The configurable priority to traffic class mapping and the user specified queue ranges are used to configure the traffic class, overriding the hardware defaults when the 'hw' option is set to 0. However, when the 'hw' option is non-zero, the hardware QOS defaults are used. This patch makes it so that we can pass the data the user provided to ndo_setup_tc. This allows us to pull in the queue configuration if the user requested it as well as any additional hardware offload type requested by using a value other than 1 for the hw value. Finally it also provides a means for the device driver to return the level supported for the offload type via the qopt->hw value. Previously we were just always assuming the value to be 1, in the future values beyond just 1 may be supported. Signed-off-by: Amritha Nambiar <amritha.nambiar@intel.com> Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* mqprio: Change handling of hw u8 to allow for multiple hardware offload modesAlexander Duyck2017-03-151-10/+16
| | | | | | | | | | | | | | | This patch is meant to allow for support of multiple hardware offload type for a single device. There is currently no bounds checking for the hw member of the mqprio_qopt structure. This results in us being able to pass values from 1 to 255 with all being treated the same. On retreiving the value it is returned as 1 for anything 1 or greater being set. With this change we are currently adding limited bounds checking by defining an enum and using those values to limit the reported hardware offloads. Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: sched: make default fifo qdiscs appear in the dumpJiri Kosina2017-03-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* net_sched: fix error recovery at qdisc creationEric Dumazet2017-02-111-13/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Dmitry reported uses after free in qdisc code [1] The problem here is that ops->init() can return an error. qdisc_create_dflt() then call ops->destroy(), while qdisc_create() does _not_ call it. Four qdisc chose to call their own ops->destroy(), assuming their caller would not. This patch makes sure qdisc_create() calls ops->destroy() and fixes the four qdisc to avoid double free. [1] BUG: KASAN: use-after-free in mq_destroy+0x242/0x290 net/sched/sch_mq.c:33 at addr ffff8801d415d440 Read of size 8 by task syz-executor2/5030 CPU: 0 PID: 5030 Comm: syz-executor2 Not tainted 4.3.5-smp-DEV #119 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000046 ffff8801b435b870 ffffffff81bbbed4 ffff8801db000400 ffff8801d415d440 ffff8801d415dc40 ffff8801c4988510 ffff8801b435b898 ffffffff816682b1 ffff8801b435b928 ffff8801d415d440 ffff8801c49880c0 Call Trace: [<ffffffff81bbbed4>] __dump_stack lib/dump_stack.c:15 [inline] [<ffffffff81bbbed4>] dump_stack+0x6c/0x98 lib/dump_stack.c:51 [<ffffffff816682b1>] kasan_object_err+0x21/0x70 mm/kasan/report.c:158 [<ffffffff81668524>] print_address_description mm/kasan/report.c:196 [inline] [<ffffffff81668524>] kasan_report_error+0x1b4/0x4b0 mm/kasan/report.c:285 [<ffffffff81668953>] kasan_report mm/kasan/report.c:305 [inline] [<ffffffff81668953>] __asan_report_load8_noabort+0x43/0x50 mm/kasan/report.c:326 [<ffffffff82527b02>] mq_destroy+0x242/0x290 net/sched/sch_mq.c:33 [<ffffffff82524bdd>] qdisc_destroy+0x12d/0x290 net/sched/sch_generic.c:953 [<ffffffff82524e30>] qdisc_create_dflt+0xf0/0x120 net/sched/sch_generic.c:848 [<ffffffff8252550d>] attach_default_qdiscs net/sched/sch_generic.c:1029 [inline] [<ffffffff8252550d>] dev_activate+0x6ad/0x880 net/sched/sch_generic.c:1064 [<ffffffff824b1db1>] __dev_open+0x221/0x320 net/core/dev.c:1403 [<ffffffff824b24ce>] __dev_change_flags+0x15e/0x3e0 net/core/dev.c:6858 [<ffffffff824b27de>] dev_change_flags+0x8e/0x140 net/core/dev.c:6926 [<ffffffff824f5bf6>] dev_ifsioc+0x446/0x890 net/core/dev_ioctl.c:260 [<ffffffff824f61fa>] dev_ioctl+0x1ba/0xb80 net/core/dev_ioctl.c:546 [<ffffffff82430509>] sock_do_ioctl+0x99/0xb0 net/socket.c:879 [<ffffffff82430d30>] sock_ioctl+0x2a0/0x390 net/socket.c:958 [<ffffffff816f3b68>] vfs_ioctl fs/ioctl.c:44 [inline] [<ffffffff816f3b68>] do_vfs_ioctl+0x8a8/0xe50 fs/ioctl.c:611 [<ffffffff816f41a4>] SYSC_ioctl fs/ioctl.c:626 [inline] [<ffffffff816f41a4>] SyS_ioctl+0x94/0xc0 fs/ioctl.c:617 [<ffffffff8123e357>] entry_SYSCALL_64_fastpath+0x12/0x17 Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: sched: convert qdisc linked list to hashtableJiri Kosina2016-08-101-1/+1
| | | | | | | | | | | | | | | Convert the per-device linked list into a hashtable. The primary motivation for this change is that currently, we're not tracking all the qdiscs in hierarchy (e.g. excluding default qdiscs), as the lookup performed over the linked list by qdisc_match_from_root() is rather expensive. The ultimate goal is to get rid of hidden qdiscs completely, which will bring much more determinism in user experience. Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: sched: do not acquire qdisc spinlock in qdisc/class stats dumpEric Dumazet2016-06-071-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* net: sched: use pfifo_fast for non real queuesEric Dumazet2016-03-031-1/+2
| | | | | | | | | | | Some devices declare a high number of TX queues, then set a much lower real_num_tx_queues This cause setups using fq_codel, sfq or fq as the default qdisc to consume more memory than really needed. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* sch_mqprio: Fix build with older gcc.David S. Miller2016-03-011-1/+1
| | | | | | | | | | | | | | | | CC [M] net/sched/sch_mqprio.o net/sched/sch_mqprio.c: In function ?mqprio_init?: net/sched/sch_mqprio.c:145: error: unknown field ?tc? specified in initializer net/sched/sch_mqprio.c:145: warning: missing braces around initializer net/sched/sch_mqprio.c:145: warning: (near initialization for ?tc.<anonymous>?) make[2]: *** [net/sched/sch_mqprio.o] Error 1 make[1]: *** [net/sched] Error 2 make: *** [net] Error 2 Several people reported this, surround the unnamed union member initialization with braces to fix. Signed-off-by: David S. Miller <davem@davemloft.net>
* net: rework setup_tc ndo op to consume general tc operandJohn Fastabend2016-02-171-3/+6
| | | | | | | | | | | | | | | This patch updates setup_tc so we can pass additional parameters into the ndo op in a generic way. To do this we provide structured union and type flag. This lets each classifier and qdisc provide its own set of attributes without having to add new ndo ops or grow the signature of the callback. Signed-off-by: John Fastabend <john.r.fastabend@intel.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>
* net: rework ndo tc op to consume additional qdisc handle parameterJohn Fastabend2016-02-171-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | The ndo_setup_tc() op was added to support drivers offloading tx qdiscs however only support for mqprio was ever added. So we only ever added support for passing the number of traffic classes to the driver. This patch generalizes the ndo_setup_tc op so that a handle can be provided to indicate if the offload is for ingress or egress or potentially even child qdiscs. CC: Murali Karicheri <m-karicheri2@ti.com> CC: Shradha Shah <sshah@solarflare.com> CC: Or Gerlitz <ogerlitz@mellanox.com> CC: Ariel Elior <ariel.elior@qlogic.com> CC: Jeff Kirsher <jeffrey.t.kirsher@intel.com> CC: Bruce Allan <bruce.w.allan@intel.com> CC: Jesse Brandeburg <jesse.brandeburg@intel.com> CC: Don Skidmore <donald.c.skidmore@intel.com> Signed-off-by: John Fastabend <john.r.fastabend@intel.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>
* net_sched: fix qdisc_tree_decrease_qlen() racesEric Dumazet2015-12-031-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | qdisc_tree_decrease_qlen() suffers from two problems on multiqueue devices. One problem is that it updates sch->q.qlen and sch->qstats.drops on the mq/mqprio root qdisc, while it should not : Daniele reported underflows errors : [ 681.774821] PAX: sch->q.qlen: 0 n: 1 [ 681.774825] PAX: size overflow detected in function qdisc_tree_decrease_qlen net/sched/sch_api.c:769 cicus.693_49 min, count: 72, decl: qlen; num: 0; context: sk_buff_head; [ 681.774954] CPU: 2 PID: 19 Comm: ksoftirqd/2 Tainted: G O 4.2.6.201511282239-1-grsec #1 [ 681.774955] Hardware name: ASUSTeK COMPUTER INC. X302LJ/X302LJ, BIOS X302LJ.202 03/05/2015 [ 681.774956] ffffffffa9a04863 0000000000000000 0000000000000000 ffffffffa990ff7c [ 681.774959] ffffc90000d3bc38 ffffffffa95d2810 0000000000000007 ffffffffa991002b [ 681.774960] ffffc90000d3bc68 ffffffffa91a44f4 0000000000000001 0000000000000001 [ 681.774962] Call Trace: [ 681.774967] [<ffffffffa95d2810>] dump_stack+0x4c/0x7f [ 681.774970] [<ffffffffa91a44f4>] report_size_overflow+0x34/0x50 [ 681.774972] [<ffffffffa94d17e2>] qdisc_tree_decrease_qlen+0x152/0x160 [ 681.774976] [<ffffffffc02694b1>] fq_codel_dequeue+0x7b1/0x820 [sch_fq_codel] [ 681.774978] [<ffffffffc02680a0>] ? qdisc_peek_dequeued+0xa0/0xa0 [sch_fq_codel] [ 681.774980] [<ffffffffa94cd92d>] __qdisc_run+0x4d/0x1d0 [ 681.774983] [<ffffffffa949b2b2>] net_tx_action+0xc2/0x160 [ 681.774985] [<ffffffffa90664c1>] __do_softirq+0xf1/0x200 [ 681.774987] [<ffffffffa90665ee>] run_ksoftirqd+0x1e/0x30 [ 681.774989] [<ffffffffa90896b0>] smpboot_thread_fn+0x150/0x260 [ 681.774991] [<ffffffffa9089560>] ? sort_range+0x40/0x40 [ 681.774992] [<ffffffffa9085fe4>] kthread+0xe4/0x100 [ 681.774994] [<ffffffffa9085f00>] ? kthread_worker_fn+0x170/0x170 [ 681.774995] [<ffffffffa95d8d1e>] ret_from_fork+0x3e/0x70 mq/mqprio have their own ways to report qlen/drops by folding stats on all their queues, with appropriate locking. A second problem is that qdisc_tree_decrease_qlen() calls qdisc_lookup() without proper locking : concurrent qdisc updates could corrupt the list that qdisc_match_from_root() parses to find a qdisc given its handle. Fix first problem adding a TCQ_F_NOPARENT qdisc flag that qdisc_tree_decrease_qlen() can use to abort its tree traversal, as soon as it meets a mq/mqprio qdisc children. Second problem can be fixed by RCU protection. Qdisc are already freed after RCU grace period, so qdisc_list_add() and qdisc_list_del() simply have to use appropriate rcu list variants. A future patch will add a per struct netdev_queue list anchor, so that qdisc_tree_decrease_qlen() can have more efficient lookups. Reported-by: Daniele Fucini <dfucini@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Cong Wang <cwang@twopensource.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: sched: enable per cpu qstatsJohn Fastabend2014-09-301-2/+3
| | | | | | | | 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>
* net: sched: restrict use of qstats qlenJohn Fastabend2014-09-301-5/+4
| | | | | | | | | | | | | | | | | | | | 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>
* net: sched: make bstats per cpu and estimator RCU safeJohn Fastabend2014-09-301-2/+2
| | | | | | | | | | | | | | | | | In order to run qdisc's without locking statistics and estimators need to be handled correctly. To resolve bstats make the statistics per cpu. And because this is only needed for qdiscs that are running without locks which is not the case for most qdiscs in the near future only create percpu stats when qdiscs set the TCQ_F_CPUSTATS flag. Next because estimators use the bstats to calculate packets per second and bytes per second the estimator code paths are updated to use the per cpu statistics. Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: qdisc: use rcu prefix and silence sparse warningsJohn Fastabend2014-09-131-2/+4
| | | | | | | | | | | | | | | Add __rcu notation to qdisc handling by doing this we can make smatch output more legible. And anyways some of the cases should be using rcu_dereference() see qdisc_all_tx_empty(), qdisc_tx_chainging(), and so on. Also *wake_queue() API is commonly called from driver timer routines without rcu lock or rtnl lock. So I added rcu_read_lock() blocks around netif_wake_subqueue and netif_tx_wake_queue. Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* pkt_sched: give visibility to mq slave qdiscsEric Dumazet2013-12-091-4/+6
| | | | | | | | | | | | | | | Commit 6da7c8fcbcbd ("qdisc: allow setting default queuing discipline") added the ability to change default qdisc from pfifo_fast to say fq But as most modern ethernet devices are multiqueue, we cant really see all the statistics from "tc -s qdisc show", as the default root qdisc is mq. This patch adds the calls to qdisc_list_add() to mq and mqprio Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* qdisc: allow setting default queuing disciplinestephen hemminger2013-08-311-1/+1
| | | | | | | | | | | | | | | | | | | | | | By default, the pfifo_fast queue discipline has been used by default for all devices. But we have better choices now. This patch allow setting the default queueing discipline with sysctl. This allows easy use of better queueing disciplines on all devices without having to use tc qdisc scripts. It is intended to allow an easy path for distributions to make fq_codel or sfq the default qdisc. This patch also makes pfifo_fast more of a first class qdisc, since it is now possible to manually override the default and explicitly use pfifo_fast. The behavior for systems who do not use the sysctl is unchanged, they still get pfifo_fast Also removes leftover random # in sysctl net core. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* pkt_sched: avoid requeues if possibleEric Dumazet2012-12-121-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With BQL being deployed, we can more likely have following behavior : We dequeue a packet from qdisc in dequeue_skb(), then we realize target tx queue is in XOFF state in sch_direct_xmit(), and we have to hold the skb into gso_skb for later. This shows in stats (tc -s qdisc dev eth0) as requeues. Problem of these requeues is that high priority packets can not be dequeued as long as this (possibly low prio and big TSO packet) is not removed from gso_skb. At 1Gbps speed, a full size TSO packet is 500 us of extra latency. In some cases, we know that all packets dequeued from a qdisc are for a particular and known txq : - If device is non multi queue - For all MQ/MQPRIO slave qdiscs This patch introduces a new qdisc flag, TCQ_F_ONETXQUEUE to mark this capability, so that dequeue_skb() is allowed to dequeue a packet only if the associated txq is not stopped. This indeed reduce latencies for high prio packets (or improve fairness with sfq/fq_codel), and almost remove qdisc 'requeues'. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* pkt_sched: Stop using NLA_PUT*().David S. Miller2012-04-011-1/+2
| | | | | | | 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>
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