1. 13 1月, 2014 6 次提交
    • D
      sched/deadline: Add SCHED_DEADLINE inheritance logic · 2d3d891d
      Dario Faggioli 提交于
      Some method to deal with rt-mutexes and make sched_dl interact with
      the current PI-coded is needed, raising all but trivial issues, that
      needs (according to us) to be solved with some restructuring of
      the pi-code (i.e., going toward a proxy execution-ish implementation).
      
      This is under development, in the meanwhile, as a temporary solution,
      what this commits does is:
      
       - ensure a pi-lock owner with waiters is never throttled down. Instead,
         when it runs out of runtime, it immediately gets replenished and it's
         deadline is postponed;
      
       - the scheduling parameters (relative deadline and default runtime)
         used for that replenishments --during the whole period it holds the
         pi-lock-- are the ones of the waiting task with earliest deadline.
      
      Acting this way, we provide some kind of boosting to the lock-owner,
      still by using the existing (actually, slightly modified by the previous
      commit) pi-architecture.
      
      We would stress the fact that this is only a surely needed, all but
      clean solution to the problem. In the end it's only a way to re-start
      discussion within the community. So, as always, comments, ideas, rants,
      etc.. are welcome! :-)
      Signed-off-by: NDario Faggioli <raistlin@linux.it>
      Signed-off-by: NJuri Lelli <juri.lelli@gmail.com>
      [ Added !RT_MUTEXES build fix. ]
      Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1383831828-15501-11-git-send-email-juri.lelli@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      2d3d891d
    • P
      rtmutex: Turn the plist into an rb-tree · fb00aca4
      Peter Zijlstra 提交于
      Turn the pi-chains from plist to rb-tree, in the rt_mutex code,
      and provide a proper comparison function for -deadline and
      -priority tasks.
      
      This is done mainly because:
       - classical prio field of the plist is just an int, which might
         not be enough for representing a deadline;
       - manipulating such a list would become O(nr_deadline_tasks),
         which might be to much, as the number of -deadline task increases.
      
      Therefore, an rb-tree is used, and tasks are queued in it according
      to the following logic:
       - among two -priority (i.e., SCHED_BATCH/OTHER/RR/FIFO) tasks, the
         one with the higher (lower, actually!) prio wins;
       - among a -priority and a -deadline task, the latter always wins;
       - among two -deadline tasks, the one with the earliest deadline
         wins.
      
      Queueing and dequeueing functions are changed accordingly, for both
      the list of a task's pi-waiters and the list of tasks blocked on
      a pi-lock.
      Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
      Signed-off-by: NDario Faggioli <raistlin@linux.it>
      Signed-off-by: NJuri Lelli <juri.lelli@gmail.com>
      Signed-off-again-by: NPeter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1383831828-15501-10-git-send-email-juri.lelli@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      fb00aca4
    • H
      sched/deadline: Add period support for SCHED_DEADLINE tasks · 755378a4
      Harald Gustafsson 提交于
      Make it possible to specify a period (different or equal than
      deadline) for -deadline tasks. Relative deadlines (D_i) are used on
      task arrivals to generate new scheduling (absolute) deadlines as "d =
      t + D_i", and periods (P_i) to postpone the scheduling deadlines as "d
      = d + P_i" when the budget is zero.
      
      This is in general useful to model (and schedule) tasks that have slow
      activation rates (long periods), but have to be scheduled soon once
      activated (short deadlines).
      Signed-off-by: NHarald Gustafsson <harald.gustafsson@ericsson.com>
      Signed-off-by: NDario Faggioli <raistlin@linux.it>
      Signed-off-by: NJuri Lelli <juri.lelli@gmail.com>
      Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1383831828-15501-7-git-send-email-juri.lelli@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      755378a4
    • J
      sched/deadline: Add SCHED_DEADLINE SMP-related data structures & logic · 1baca4ce
      Juri Lelli 提交于
      Introduces data structures relevant for implementing dynamic
      migration of -deadline tasks and the logic for checking if
      runqueues are overloaded with -deadline tasks and for choosing
      where a task should migrate, when it is the case.
      
      Adds also dynamic migrations to SCHED_DEADLINE, so that tasks can
      be moved among CPUs when necessary. It is also possible to bind a
      task to a (set of) CPU(s), thus restricting its capability of
      migrating, or forbidding migrations at all.
      
      The very same approach used in sched_rt is utilised:
       - -deadline tasks are kept into CPU-specific runqueues,
       - -deadline tasks are migrated among runqueues to achieve the
         following:
          * on an M-CPU system the M earliest deadline ready tasks
            are always running;
          * affinity/cpusets settings of all the -deadline tasks is
            always respected.
      
      Therefore, this very special form of "load balancing" is done with
      an active method, i.e., the scheduler pushes or pulls tasks between
      runqueues when they are woken up and/or (de)scheduled.
      IOW, every time a preemption occurs, the descheduled task might be sent
      to some other CPU (depending on its deadline) to continue executing
      (push). On the other hand, every time a CPU becomes idle, it might pull
      the second earliest deadline ready task from some other CPU.
      
      To enforce this, a pull operation is always attempted before taking any
      scheduling decision (pre_schedule()), as well as a push one after each
      scheduling decision (post_schedule()). In addition, when a task arrives
      or wakes up, the best CPU where to resume it is selected taking into
      account its affinity mask, the system topology, but also its deadline.
      E.g., from the scheduling point of view, the best CPU where to wake
      up (and also where to push) a task is the one which is running the task
      with the latest deadline among the M executing ones.
      
      In order to facilitate these decisions, per-runqueue "caching" of the
      deadlines of the currently running and of the first ready task is used.
      Queued but not running tasks are also parked in another rb-tree to
      speed-up pushes.
      Signed-off-by: NJuri Lelli <juri.lelli@gmail.com>
      Signed-off-by: NDario Faggioli <raistlin@linux.it>
      Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1383831828-15501-5-git-send-email-juri.lelli@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      1baca4ce
    • D
      sched/deadline: Add SCHED_DEADLINE structures & implementation · aab03e05
      Dario Faggioli 提交于
      Introduces the data structures, constants and symbols needed for
      SCHED_DEADLINE implementation.
      
      Core data structure of SCHED_DEADLINE are defined, along with their
      initializers. Hooks for checking if a task belong to the new policy
      are also added where they are needed.
      
      Adds a scheduling class, in sched/dl.c and a new policy called
      SCHED_DEADLINE. It is an implementation of the Earliest Deadline
      First (EDF) scheduling algorithm, augmented with a mechanism (called
      Constant Bandwidth Server, CBS) that makes it possible to isolate
      the behaviour of tasks between each other.
      
      The typical -deadline task will be made up of a computation phase
      (instance) which is activated on a periodic or sporadic fashion. The
      expected (maximum) duration of such computation is called the task's
      runtime; the time interval by which each instance need to be completed
      is called the task's relative deadline. The task's absolute deadline
      is dynamically calculated as the time instant a task (better, an
      instance) activates plus the relative deadline.
      
      The EDF algorithms selects the task with the smallest absolute
      deadline as the one to be executed first, while the CBS ensures each
      task to run for at most its runtime every (relative) deadline
      length time interval, avoiding any interference between different
      tasks (bandwidth isolation).
      Thanks to this feature, also tasks that do not strictly comply with
      the computational model sketched above can effectively use the new
      policy.
      
      To summarize, this patch:
       - introduces the data structures, constants and symbols needed;
       - implements the core logic of the scheduling algorithm in the new
         scheduling class file;
       - provides all the glue code between the new scheduling class and
         the core scheduler and refines the interactions between sched/dl
         and the other existing scheduling classes.
      Signed-off-by: NDario Faggioli <raistlin@linux.it>
      Signed-off-by: NMichael Trimarchi <michael@amarulasolutions.com>
      Signed-off-by: NFabio Checconi <fchecconi@gmail.com>
      Signed-off-by: NJuri Lelli <juri.lelli@gmail.com>
      Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1383831828-15501-4-git-send-email-juri.lelli@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      aab03e05
    • D
      sched: Add new scheduler syscalls to support an extended scheduling parameters ABI · d50dde5a
      Dario Faggioli 提交于
      Add the syscalls needed for supporting scheduling algorithms
      with extended scheduling parameters (e.g., SCHED_DEADLINE).
      
      In general, it makes possible to specify a periodic/sporadic task,
      that executes for a given amount of runtime at each instance, and is
      scheduled according to the urgency of their own timing constraints,
      i.e.:
      
       - a (maximum/typical) instance execution time,
       - a minimum interval between consecutive instances,
       - a time constraint by which each instance must be completed.
      
      Thus, both the data structure that holds the scheduling parameters of
      the tasks and the system calls dealing with it must be extended.
      Unfortunately, modifying the existing struct sched_param would break
      the ABI and result in potentially serious compatibility issues with
      legacy binaries.
      
      For these reasons, this patch:
      
       - defines the new struct sched_attr, containing all the fields
         that are necessary for specifying a task in the computational
         model described above;
      
       - defines and implements the new scheduling related syscalls that
         manipulate it, i.e., sched_setattr() and sched_getattr().
      
      Syscalls are introduced for x86 (32 and 64 bits) and ARM only, as a
      proof of concept and for developing and testing purposes. Making them
      available on other architectures is straightforward.
      
      Since no "user" for these new parameters is introduced in this patch,
      the implementation of the new system calls is just identical to their
      already existing counterpart. Future patches that implement scheduling
      policies able to exploit the new data structure must also take care of
      modifying the sched_*attr() calls accordingly with their own purposes.
      Signed-off-by: NDario Faggioli <raistlin@linux.it>
      [ Rewrote to use sched_attr. ]
      Signed-off-by: NJuri Lelli <juri.lelli@gmail.com>
      [ Removed sched_setscheduler2() for now. ]
      Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1383831828-15501-3-git-send-email-juri.lelli@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      d50dde5a
  2. 11 1月, 2014 1 次提交
    • J
      net: core: explicitly select a txq before doing l2 forwarding · f663dd9a
      Jason Wang 提交于
      Currently, the tx queue were selected implicitly in ndo_dfwd_start_xmit(). The
      will cause several issues:
      
      - NETIF_F_LLTX were removed for macvlan, so txq lock were done for macvlan
        instead of lower device which misses the necessary txq synchronization for
        lower device such as txq stopping or frozen required by dev watchdog or
        control path.
      - dev_hard_start_xmit() was called with NULL txq which bypasses the net device
        watchdog.
      - dev_hard_start_xmit() does not check txq everywhere which will lead a crash
        when tso is disabled for lower device.
      
      Fix this by explicitly introducing a new param for .ndo_select_queue() for just
      selecting queues in the case of l2 forwarding offload. netdev_pick_tx() was also
      extended to accept this parameter and dev_queue_xmit_accel() was used to do l2
      forwarding transmission.
      
      With this fixes, NETIF_F_LLTX could be preserved for macvlan and there's no need
      to check txq against NULL in dev_hard_start_xmit(). Also there's no need to keep
      a dedicated ndo_dfwd_start_xmit() and we can just reuse the code of
      dev_queue_xmit() to do the transmission.
      
      In the future, it was also required for macvtap l2 forwarding support since it
      provides a necessary synchronization method.
      
      Cc: John Fastabend <john.r.fastabend@intel.com>
      Cc: Neil Horman <nhorman@tuxdriver.com>
      Cc: e1000-devel@lists.sourceforge.net
      Signed-off-by: NJason Wang <jasowang@redhat.com>
      Acked-by: NNeil Horman <nhorman@tuxdriver.com>
      Acked-by: NJohn Fastabend <john.r.fastabend@intel.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f663dd9a
  3. 03 1月, 2014 1 次提交
    • W
      ipv4: fix tunneled VM traffic over hw VXLAN/GRE GSO NIC · 7a7ffbab
      Wei-Chun Chao 提交于
      VM to VM GSO traffic is broken if it goes through VXLAN or GRE
      tunnel and the physical NIC on the host supports hardware VXLAN/GRE
      GSO offload (e.g. bnx2x and next-gen mlx4).
      
      Two issues -
      (VXLAN) VM traffic has SKB_GSO_DODGY and SKB_GSO_UDP_TUNNEL with
      SKB_GSO_TCP/UDP set depending on the inner protocol. GSO header
      integrity check fails in udp4_ufo_fragment if inner protocol is
      TCP. Also gso_segs is calculated incorrectly using skb->len that
      includes tunnel header. Fix: robust check should only be applied
      to the inner packet.
      
      (VXLAN & GRE) Once GSO header integrity check passes, NULL segs
      is returned and the original skb is sent to hardware. However the
      tunnel header is already pulled. Fix: tunnel header needs to be
      restored so that hardware can perform GSO properly on the original
      packet.
      Signed-off-by: NWei-Chun Chao <weichunc@plumgrid.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      7a7ffbab
  4. 01 1月, 2014 1 次提交
    • D
      vlan: Fix header ops passthru when doing TX VLAN offload. · 2205369a
      David S. Miller 提交于
      When the vlan code detects that the real device can do TX VLAN offloads
      in hardware, it tries to arrange for the real device's header_ops to
      be invoked directly.
      
      But it does so illegally, by simply hooking the real device's
      header_ops up to the VLAN device.
      
      This doesn't work because we will end up invoking a set of header_ops
      routines which expect a device type which matches the real device, but
      will see a VLAN device instead.
      
      Fix this by providing a pass-thru set of header_ops which will arrange
      to pass the proper real device instead.
      
      To facilitate this add a dev_rebuild_header().  There are
      implementations which provide a ->cache and ->create but not a
      ->rebuild (f.e. PLIP).  So we need a helper function just like
      dev_hard_header() to avoid crashes.
      
      Use this helper in the one existing place where the
      header_ops->rebuild was being invoked, the neighbour code.
      
      With lots of help from Florian Westphal.
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2205369a
  5. 28 12月, 2013 1 次提交
  6. 25 12月, 2013 1 次提交
  7. 22 12月, 2013 1 次提交
    • B
      aio/migratepages: make aio migrate pages sane · 8e321fef
      Benjamin LaHaise 提交于
      The arbitrary restriction on page counts offered by the core
      migrate_page_move_mapping() code results in rather suspicious looking
      fiddling with page reference counts in the aio_migratepage() operation.
      To fix this, make migrate_page_move_mapping() take an extra_count parameter
      that allows aio to tell the code about its own reference count on the page
      being migrated.
      
      While cleaning up aio_migratepage(), make it validate that the old page
      being passed in is actually what aio_migratepage() expects to prevent
      misbehaviour in the case of races.
      Signed-off-by: NBenjamin LaHaise <bcrl@kvack.org>
      8e321fef
  8. 21 12月, 2013 2 次提交
  9. 19 12月, 2013 5 次提交
  10. 18 12月, 2013 1 次提交
  11. 17 12月, 2013 2 次提交
  12. 13 12月, 2013 5 次提交
  13. 12 12月, 2013 1 次提交
  14. 11 12月, 2013 5 次提交
  15. 08 12月, 2013 2 次提交
  16. 06 12月, 2013 2 次提交
    • P
      xen-netback: fix fragment detection in checksum setup · 1431fb31
      Paul Durrant 提交于
      The code to detect fragments in checksum_setup() was missing for IPv4 and
      too eager for IPv6. (It transpires that Windows seems to send IPv6 packets
      with a fragment header even if they are not a fragment - i.e. offset is zero,
      and M bit is not set).
      
      This patch also incorporates a fix to callers of maybe_pull_tail() where
      skb->network_header was being erroneously added to the length argument.
      Signed-off-by: NPaul Durrant <paul.durrant@citrix.com>
      Signed-off-by: NZoltan Kiss <zoltan.kiss@citrix.com>
      Cc: Wei Liu <wei.liu2@citrix.com>
      Cc: Ian Campbell <ian.campbell@citrix.com>
      Cc: David Vrabel <david.vrabel@citrix.com>
      cc: David Miller <davem@davemloft.net>
      Acked-by: NWei Liu <wei.liu2@citrix.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      1431fb31
    • T
      percpu: fix spurious sparse warnings from DEFINE_PER_CPU() · b1a0fbfd
      Tejun Heo 提交于
      When CONFIG_DEBUG_FORCE_WEAK_PER_CPU or CONFIG_ARCH_NEEDS_WEAK_PER_CPU
      is set, DEFINE_PER_CPU() explodes into cryptic series of definitions
      to still allow using "static" for percpu variables while keeping all
      per-cpu symbols unique in the kernel image which is required for weak
      symbols.  This ultimately converts the actual symbol to global whether
      DEFINE_PER_CPU() is prefixed with static or not.
      
      Unfortunately, the macro forgot to add explicit extern declartion of
      the actual symbol ending up defining global symbol without preceding
      declaration for static definitions which naturally don't have matching
      DECLARE_PER_CPU().  The only ill effect is triggering of the following
      warnings.
      
       fs/inode.c:74:8: warning: symbol 'nr_inodes' was not declared. Should it be static?
       fs/inode.c:75:8: warning: symbol 'nr_unused' was not declared. Should it be static?
      
      Fix it by adding extern declaration in the DEFINE_PER_CPU() macro.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Reported-by: NWanlong Gao <gaowanlong@cn.fujitsu.com>
      Tested-by: NWanlong Gao <gaowanlong@cn.fujitsu.com>
      b1a0fbfd
  17. 03 12月, 2013 3 次提交