1. 07 Jun, 2016 1 commit
  2. 06 Jun, 2016 1 commit
  3. 16 May, 2016 1 commit
  4. 03 Mar, 2016 1 commit
  5. 29 Feb, 2016 2 commits
  6. 10 Jan, 2016 1 commit
  7. 03 Dec, 2015 1 commit
    • Eric Dumazet's avatar
      net_sched: fix qdisc_tree_decrease_qlen() races · 4eaf3b84
      Eric Dumazet authored
      qdisc_tree_decrease_qlen() suffers from two problems on multiqueue
      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 #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: default avatarDaniele Fucini <dfucini@gmail.com>
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Cc: Cong Wang <cwang@twopensource.com>
      Cc: Jamal Hadi Salim <jhs@mojatatu.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
  8. 17 Sep, 2015 2 commits
    • Alexei Starovoitov's avatar
      bpf: add bpf_redirect() helper · 27b29f63
      Alexei Starovoitov authored
      Existing bpf_clone_redirect() helper clones skb before redirecting
      it to RX or TX of destination netdev.
      Introduce bpf_redirect() helper that does that without cloning.
      Benchmarked with two hosts using 10G ixgbe NICs.
      One host is doing line rate pktgen.
      Another host is configured as:
      $ tc qdisc add dev $dev ingress
      $ tc filter add dev $dev root pref 10 u32 match u32 0 0 flowid 1:2 \
         action bpf run object-file tcbpf1_kern.o section clone_redirect_xmit drop
      so it receives the packet on $dev and immediately xmits it on $dev + 1
      The section 'clone_redirect_xmit' in tcbpf1_kern.o file has the program
      that does bpf_clone_redirect() and performance is 2.0 Mpps
      $ tc filter add dev $dev root pref 10 u32 match u32 0 0 flowid 1:2 \
         action bpf run object-file tcbpf1_kern.o section redirect_xmit drop
      which is using bpf_redirect() - 2.4 Mpps
      and using cls_bpf with integrated actions as:
      $ tc filter add dev $dev root pref 10 \
        bpf run object-file tcbpf1_kern.o section redirect_xmit integ_act classid 1
      performance is 2.5 Mpps
      To summarize:
      u32+act_bpf using clone_redirect - 2.0 Mpps
      u32+act_bpf using redirect - 2.4 Mpps
      cls_bpf using redirect - 2.5 Mpps
      For comparison linux bridge in this setup is doing 2.1 Mpps
      and ixgbe rx + drop in ip_rcv - 7.8 Mpps
      Signed-off-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
      Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      Acked-by: default avatarJohn Fastabend <john.r.fastabend@intel.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    • Daniel Borkmann's avatar
      cls_bpf: introduce integrated actions · 045efa82
      Daniel Borkmann authored
      Often cls_bpf classifier is used with single action drop attached.
      Optimize this use case and let cls_bpf return both classid and action.
      For backwards compatibility reasons enable this feature under
      Then more interesting programs like the following are easier to write:
      int cls_bpf_prog(struct __sk_buff *skb)
        /* classify arp, ip, ipv6 into different traffic classes
         * and drop all other packets
        switch (skb->protocol) {
        case htons(ETH_P_ARP):
          skb->tc_classid = 1;
        case htons(ETH_P_IP):
          skb->tc_classid = 2;
        case htons(ETH_P_IPV6):
          skb->tc_classid = 3;
          return TC_ACT_SHOT;
        return TC_ACT_OK;
      Joint work with Daniel Borkmann.
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      Signed-off-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
  9. 27 Aug, 2015 1 commit
  10. 08 Jul, 2015 1 commit
  11. 13 May, 2015 1 commit
  12. 11 May, 2015 1 commit
  13. 02 May, 2015 1 commit
  14. 09 Mar, 2015 1 commit
    • Cong Wang's avatar
      net_sched: destroy proto tp when all filters are gone · 1e052be6
      Cong Wang authored
      Kernel automatically creates a tp for each
      (kind, protocol, priority) tuple, which has handle 0,
      when we add a new filter, but it still is left there
      after we remove our own, unless we don't specify the
      handle (literally means all the filters under
      the tuple). For example this one is left:
        # tc filter show dev eth0
        filter parent 8001: protocol arp pref 49152 basic
      The user-space is hard to clean up these for kernel
      because filters like u32 are organized in a complex way.
      So kernel is responsible to remove it after all filters
      are gone.  Each type of filter has its own way to
      store the filters, so each type has to provide its
      way to check if all filters are gone.
      Cc: Jamal Hadi Salim <jhs@mojatatu.com>
      Signed-off-by: default avatarCong Wang <cwang@twopensource.com>
      Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
      Acked-by: Jamal Hadi Salim<jhs@mojatatu.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
  15. 31 Jan, 2015 1 commit
    • Eric Dumazet's avatar
      net: sched: fix panic in rate estimators · 0d32ef8c
      Eric Dumazet authored
      Doing the following commands on a non idle network device
      panics the box instantly, because cpu_bstats gets overwritten
      by stats.
      tc qdisc add dev eth0 root <your_favorite_qdisc>
      ... some traffic (one packet is enough) ...
      tc qdisc replace dev eth0 root est 1sec 4sec <your_favorite_qdisc>
      [  325.355596] BUG: unable to handle kernel paging request at ffff8841dc5a074c
      [  325.362609] IP: [<ffffffff81541c9e>] __gnet_stats_copy_basic+0x3e/0x90
      [  325.369158] PGD 1fa7067 PUD 0
      [  325.372254] Oops: 0000 [#1] SMP
      [  325.375514] Modules linked in: ...
      [  325.398346] CPU: 13 PID: 14313 Comm: tc Not tainted 3.19.0-smp-DEV #1163
      [  325.412042] task: ffff8800793ab5d0 ti: ffff881ff2fa4000 task.ti: ffff881ff2fa4000
      [  325.419518] RIP: 0010:[<ffffffff81541c9e>]  [<ffffffff81541c9e>] __gnet_stats_copy_basic+0x3e/0x90
      [  325.428506] RSP: 0018:ffff881ff2fa7928  EFLAGS: 00010286
      [  325.433824] RAX: 000000000000000c RBX: ffff881ff2fa796c RCX: 000000000000000c
      [  325.440988] RDX: ffff8841dc5a0744 RSI: 0000000000000060 RDI: 0000000000000060
      [  325.448120] RBP: ffff881ff2fa7948 R08: ffffffff81cd4f80 R09: 0000000000000000
      [  325.455268] R10: ffff883ff223e400 R11: 0000000000000000 R12: 000000015cba0744
      [  325.462405] R13: ffffffff81cd4f80 R14: ffff883ff223e460 R15: ffff883feea0722c
      [  325.469536] FS:  00007f2ee30fa700(0000) GS:ffff88407fa20000(0000) knlGS:0000000000000000
      [  325.477630] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      [  325.483380] CR2: ffff8841dc5a074c CR3: 0000003feeae9000 CR4: 00000000001407e0
      [  325.490510] Stack:
      [  325.492524]  ffff883feea0722c ffff883fef719dc0 ffff883feea0722c ffff883ff223e4a0
      [  325.499990]  ffff881ff2fa79a8 ffffffff815424ee ffff883ff223e49c 000000015cba0744
      [  325.507460]  00000000f2fa7978 0000000000000000 ffff881ff2fa79a8 ffff883ff223e4a0
      [  325.514956] Call Trace:
      [  325.517412]  [<ffffffff815424ee>] gen_new_estimator+0x8e/0x230
      [  325.523250]  [<ffffffff815427aa>] gen_replace_estimator+0x4a/0x60
      [  325.529349]  [<ffffffff815718ab>] tc_modify_qdisc+0x52b/0x590
      [  325.535117]  [<ffffffff8155edd0>] rtnetlink_rcv_msg+0xa0/0x240
      [  325.540963]  [<ffffffff8155ed30>] ? __rtnl_unlock+0x20/0x20
      [  325.546532]  [<ffffffff8157f811>] netlink_rcv_skb+0xb1/0xc0
      [  325.552145]  [<ffffffff8155b355>] rtnetlink_rcv+0x25/0x40
      [  325.557558]  [<ffffffff8157f0d8>] netlink_unicast+0x168/0x220
      [  325.563317]  [<ffffffff8157f47c>] netlink_sendmsg+0x2ec/0x3e0
      Lets play safe and not use an union : percpu 'pointers' are mostly read
      anyway, and we have typically few qdiscs per host.
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Cc: John Fastabend <john.fastabend@gmail.com>
      Fixes: 22e0f8b9 ("net: sched: make bstats per cpu and estimator RCU safe")
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
  16. 09 Dec, 2014 1 commit
  17. 03 Oct, 2014 1 commit
    • Jesper Dangaard Brouer's avatar
      qdisc: bulk dequeue support for qdiscs with TCQ_F_ONETXQUEUE · 5772e9a3
      Jesper Dangaard Brouer authored
      Based on DaveM's recent API work on dev_hard_start_xmit(), that allows
      sending/processing an entire skb list.
      This patch implements qdisc bulk dequeue, by allowing multiple packets
      to be dequeued in dequeue_skb().
      The optimization principle for this is two fold, (1) to amortize
      locking cost and (2) avoid expensive tailptr update for notifying HW.
       (1) Several packets are dequeued while holding the qdisc root_lock,
      amortizing locking cost over several packet.  The dequeued SKB list is
      processed under the TXQ lock in dev_hard_start_xmit(), thus also
      amortizing the cost of the TXQ lock.
       (2) Further more, dev_hard_start_xmit() will utilize the skb->xmit_more
      API to delay HW tailptr update, which also reduces the cost per
      One restriction of the new API is that every SKB must belong to the
      same TXQ.  This patch takes the easy way out, by restricting bulk
      dequeue to qdisc's with the TCQ_F_ONETXQUEUE flag, that specifies the
      qdisc only have attached a single TXQ.
      Some detail about the flow; dev_hard_start_xmit() will process the skb
      list, and transmit packets individually towards the driver (see
      xmit_one()).  In case the driver stops midway in the list, the
      remaining skb list is returned by dev_hard_start_xmit().  In
      sch_direct_xmit() this returned list is requeued by dev_requeue_skb().
      To avoid overshooting the HW limits, which results in requeuing, the
      patch limits the amount of bytes dequeued, based on the drivers BQL
      limits.  In-effect bulking will only happen for BQL enabled drivers.
      Small amounts for extra HoL blocking (2x MTU/0.24ms) were
      measured at 100Mbit/s, with bulking 8 packets, but the
      oscillating nature of the measurement indicate something, like
      sched latency might be causing this effect. More comparisons
      show, that this oscillation goes away occationally. Thus, we
      disregard this artifact completely and remove any "magic" bulking
      For now, as a conservative approach, stop bulking when seeing TSO and
      segmented GSO packets.  They already benefit from bulking on their own.
      A followup patch add this, to allow easier bisect-ability for finding
      Jointed work with Hannes, Daniel and Florian.
      Signed-off-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
      Signed-off-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
      Signed-off-by: default avatarDaniel Borkmann <dborkman@redhat.com>
      Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
  18. 29 Sep, 2014 3 commits
  19. 22 Sep, 2014 1 commit
    • Eric Dumazet's avatar
      net: sched: shrink struct qdisc_skb_cb to 28 bytes · 25711786
      Eric Dumazet authored
      We cannot make struct qdisc_skb_cb bigger without impacting IPoIB,
      or increasing skb->cb[] size.
      Commit e0f31d84 ("flow_keys: Record IP layer protocol in
      skb_flow_dissect()") broke IPoIB.
      Only current offender is sch_choke, and this one do not need an
      absolutely precise flow key.
      If we store 17 bytes of flow key, its more than enough. (Its the actual
      size of flow_keys if it was a packed structure, but we might add new
      fields at the end of it later)
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Fixes: e0f31d84 ("flow_keys: Record IP layer protocol in skb_flow_dissect()")
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
  20. 13 Sep, 2014 4 commits
  21. 23 Jun, 2014 1 commit
  22. 27 Apr, 2014 1 commit
  23. 13 Jan, 2014 1 commit
  24. 18 Dec, 2013 1 commit
  25. 20 Sep, 2013 1 commit
  26. 31 Aug, 2013 1 commit
  27. 30 Aug, 2013 1 commit
    • stephen hemminger's avatar
      qdisc: allow setting default queuing discipline · 6da7c8fc
      stephen hemminger authored
      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
      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: default avatarStephen Hemminger <stephen@networkplumber.org>
      Acked-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
  28. 15 Aug, 2013 1 commit
    • Jesper Dangaard Brouer's avatar
      net_sched: restore "linklayer atm" handling · 8a8e3d84
      Jesper Dangaard Brouer authored
      commit 56b765b7 ("htb: improved accuracy at high rates")
      broke the "linklayer atm" handling.
       tc class add ... htb rate X ceil Y linklayer atm
      The linklayer setting is implemented by modifying the rate table
      which is send to the kernel.  No direct parameter were
      transferred to the kernel indicating the linklayer setting.
      The commit 56b765b7 ("htb: improved accuracy at high rates")
      removed the use of the rate table system.
      To keep compatible with older iproute2 utils, this patch detects
      the linklayer by parsing the rate table.  It also supports future
      versions of iproute2 to send this linklayer parameter to the
      kernel directly. This is done by using the __reserved field in
      struct tc_ratespec, to convey the choosen linklayer option, but
      only using the lower 4 bits of this field.
      Linklayer detection is limited to speeds below 100Mbit/s, because
      at high rates the rtab is gets too inaccurate, so bad that
      several fields contain the same values, this resembling the ATM
      detect.  Fields even start to contain "0" time to send, e.g. at
      1000Mbit/s sending a 96 bytes packet cost "0", thus the rtab have
      been more broken than we first realized.
      Signed-off-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
  29. 31 Jul, 2013 1 commit
  30. 11 Jun, 2013 2 commits
    • Eric Dumazet's avatar
      net_sched: psched_ratecfg_precompute() improvements · 130d3d68
      Eric Dumazet authored
      Before allowing 64bits bytes rates, refactor
      psched_ratecfg_precompute() to get better comments
      and increased accuracy.
      rate_bps field is renamed to rate_bytes_ps, as we only
      have to worry about bytes per second.
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Cc: Ben Greear <greearb@candelatech.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    • Eric Dumazet's avatar
      net_sched: add 64bit rate estimators · 45203a3b
      Eric Dumazet authored
      struct gnet_stats_rate_est contains u32 fields, so the bytes per second
      field can wrap at 34360Mbit.
      Add a new gnet_stats_rate_est64 structure to get 64bit bps/pps fields,
      and switch the kernel to use this structure natively.
      This structure is dumped to user space as a new attribute :
      Old tc command will now display the capped bps (to 34360Mbit), instead
      of wrapped values, and updated tc command will display correct
      Old tc command output, after patch :
      eric:~# tc -s -d qd sh dev lo
      qdisc pfifo 8001: root refcnt 2 limit 1000p
       Sent 80868245400 bytes 1978837 pkt (dropped 0, overlimits 0 requeues 0)
       rate 34360Mbit 189696pps backlog 0b 0p requeues 0
      This patch carefully reorganizes "struct Qdisc" layout to get optimal
      performance on SMP.
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Cc: Ben Hutchings <bhutchings@solarflare.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
  31. 02 Jun, 2013 1 commit
  32. 27 Feb, 2013 1 commit
    • Sasha Levin's avatar
      hlist: drop the node parameter from iterators · b67bfe0d
      Sasha Levin authored
      I'm not sure why, but the hlist for each entry iterators were conceived
              list_for_each_entry(pos, head, member)
      The hlist ones were greedy and wanted an extra parameter:
              hlist_for_each_entry(tpos, pos, head, member)
      Why did they need an extra pos parameter? I'm not quite sure. Not only
      they don't really need it, it also prevents the iterator from looking
      exactly like the list iterator, which is unfortunate.
      Besides the semantic patch, there was some manual work required:
       - Fix up the actual hlist iterators in linux/list.h
       - Fix up the declaration of other iterators based on the hlist ones.
       - A very small amount of places were using the 'node' parameter, this
       was modified to use 'obj->member' instead.
       - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
       properly, so those had to be fixed up manually.
      The semantic patch which is mostly the work of Peter Senna Tschudin is here:
      iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;
      type T;
      expression a,c,d,e;
      identifier b;
      statement S;
      -T b;
          <+... when != b
      - b,
      c, d) S
      - b,
      c) S
      - b,
      c) S
      - b,
      c, d) S
      - b,
      c, d) S
      - b,
      c) S
      for_each_busy_worker(a, c,
      - b,
      d) S
      - b,
      c) S
      - b,
      c) S
      - b,
      c) S
      - b,
      c) S
      - b,
      c) S
      - b,
      c) S
      -(a, b)
      + sk_for_each_from(a) S
      - b,
      c, d) S
      - b,
      c) S
      - b,
      c, d, e) S
      - b,
      c) S
      - b,
      c) S
      - b,
      c, d) S
      - b,
      c) S
      - b,
      c, d) S
      - for_each_gfn_sp(a, c, d, b) S
      + for_each_gfn_sp(a, c, d) S
      - for_each_gfn_indirect_valid_sp(a, c, d, b) S
      + for_each_gfn_indirect_valid_sp(a, c, d) S
      - b,
      c) S
      - b,
      c, d) S
      - b,
      c, d) S
      [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
      [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
      [akpm@linux-foundation.org: checkpatch fixes]
      [akpm@linux-foundation.org: fix warnings]
      [akpm@linux-foudnation.org: redo intrusive kvm changes]
      Tested-by: default avatarPeter Senna Tschudin <peter.senna@gmail.com>
      Acked-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      Cc: Wu Fengguang <fengguang.wu@intel.com>
      Cc: Marcelo Tosatti <mtosatti@redhat.com>
      Cc: Gleb Natapov <gleb@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>