1. 26 10月, 2010 1 次提交
  2. 16 5月, 2010 1 次提交
    • E
      net: Consistent skb timestamping · 3b098e2d
      Eric Dumazet 提交于
      With RPS inclusion, skb timestamping is not consistent in RX path.
      
      If netif_receive_skb() is used, its deferred after RPS dispatch.
      
      If netif_rx() is used, its done before RPS dispatch.
      
      This can give strange tcpdump timestamps results.
      
      I think timestamping should be done as soon as possible in the receive
      path, to get meaningful values (ie timestamps taken at the time packet
      was delivered by NIC driver to our stack), even if NAPI already can
      defer timestamping a bit (RPS can help to reduce the gap)
      
      Tom Herbert prefer to sample timestamps after RPS dispatch. In case
      sampling is expensive (HPET/acpi_pm on x86), this makes sense.
      
      Let admins switch from one mode to another, using a new
      sysctl, /proc/sys/net/core/netdev_tstamp_prequeue
      
      Its default value (1), means timestamps are taken as soon as possible,
      before backlog queueing, giving accurate timestamps.
      
      Setting a 0 value permits to sample timestamps when processing backlog,
      after RPS dispatch, to lower the load of the pre-RPS cpu.
      Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      3b098e2d
  3. 17 4月, 2010 1 次提交
    • T
      rfs: Receive Flow Steering · fec5e652
      Tom Herbert 提交于
      This patch implements receive flow steering (RFS).  RFS steers
      received packets for layer 3 and 4 processing to the CPU where
      the application for the corresponding flow is running.  RFS is an
      extension of Receive Packet Steering (RPS).
      
      The basic idea of RFS is that when an application calls recvmsg
      (or sendmsg) the application's running CPU is stored in a hash
      table that is indexed by the connection's rxhash which is stored in
      the socket structure.  The rxhash is passed in skb's received on
      the connection from netif_receive_skb.  For each received packet,
      the associated rxhash is used to look up the CPU in the hash table,
      if a valid CPU is set then the packet is steered to that CPU using
      the RPS mechanisms.
      
      The convolution of the simple approach is that it would potentially
      allow OOO packets.  If threads are thrashing around CPUs or multiple
      threads are trying to read from the same sockets, a quickly changing
      CPU value in the hash table could cause rampant OOO packets--
      we consider this a non-starter.
      
      To avoid OOO packets, this solution implements two types of hash
      tables: rps_sock_flow_table and rps_dev_flow_table.
      
      rps_sock_table is a global hash table.  Each entry is just a CPU
      number and it is populated in recvmsg and sendmsg as described above.
      This table contains the "desired" CPUs for flows.
      
      rps_dev_flow_table is specific to each device queue.  Each entry
      contains a CPU and a tail queue counter.  The CPU is the "current"
      CPU for a matching flow.  The tail queue counter holds the value
      of a tail queue counter for the associated CPU's backlog queue at
      the time of last enqueue for a flow matching the entry.
      
      Each backlog queue has a queue head counter which is incremented
      on dequeue, and so a queue tail counter is computed as queue head
      count + queue length.  When a packet is enqueued on a backlog queue,
      the current value of the queue tail counter is saved in the hash
      entry of the rps_dev_flow_table.
      
      And now the trick: when selecting the CPU for RPS (get_rps_cpu)
      the rps_sock_flow table and the rps_dev_flow table for the RX queue
      are consulted.  When the desired CPU for the flow (found in the
      rps_sock_flow table) does not match the current CPU (found in the
      rps_dev_flow table), the current CPU is changed to the desired CPU
      if one of the following is true:
      
      - The current CPU is unset (equal to RPS_NO_CPU)
      - Current CPU is offline
      - The current CPU's queue head counter >= queue tail counter in the
      rps_dev_flow table.  This checks if the queue tail has advanced
      beyond the last packet that was enqueued using this table entry.
      This guarantees that all packets queued using this entry have been
      dequeued, thus preserving in order delivery.
      
      Making each queue have its own rps_dev_flow table has two advantages:
      1) the tail queue counters will be written on each receive, so
      keeping the table local to interrupting CPU s good for locality.  2)
      this allows lockless access to the table-- the CPU number and queue
      tail counter need to be accessed together under mutual exclusion
      from netif_receive_skb, we assume that this is only called from
      device napi_poll which is non-reentrant.
      
      This patch implements RFS for TCP and connected UDP sockets.
      It should be usable for other flow oriented protocols.
      
      There are two configuration parameters for RFS.  The
      "rps_flow_entries" kernel init parameter sets the number of
      entries in the rps_sock_flow_table, the per rxqueue sysfs entry
      "rps_flow_cnt" contains the number of entries in the rps_dev_flow
      table for the rxqueue.  Both are rounded to power of two.
      
      The obvious benefit of RFS (over just RPS) is that it achieves
      CPU locality between the receive processing for a flow and the
      applications processing; this can result in increased performance
      (higher pps, lower latency).
      
      The benefits of RFS are dependent on cache hierarchy, application
      load, and other factors.  On simple benchmarks, we don't necessarily
      see improvement and sometimes see degradation.  However, for more
      complex benchmarks and for applications where cache pressure is
      much higher this technique seems to perform very well.
      
      Below are some benchmark results which show the potential benfit of
      this patch.  The netperf test has 500 instances of netperf TCP_RR
      test with 1 byte req. and resp.  The RPC test is an request/response
      test similar in structure to netperf RR test ith 100 threads on
      each host, but does more work in userspace that netperf.
      
      e1000e on 8 core Intel
         No RFS or RPS		104K tps at 30% CPU
         No RFS (best RPS config):    290K tps at 63% CPU
         RFS				303K tps at 61% CPU
      
      RPC test	tps	CPU%	50/90/99% usec latency	Latency StdDev
        No RFS/RPS	103K	48%	757/900/3185		4472.35
        RPS only:	174K	73%	415/993/2468		491.66
        RFS		223K	73%	379/651/1382		315.61
      Signed-off-by: NTom Herbert <therbert@google.com>
      Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      fec5e652
  4. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo 提交于
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  5. 26 11月, 2009 1 次提交
  6. 12 11月, 2009 1 次提交
    • E
      sysctl net: Remove unused binary sysctl code · f8572d8f
      Eric W. Biederman 提交于
      Now that sys_sysctl is a compatiblity wrapper around /proc/sys
      all sysctl strategy routines, and all ctl_name and strategy
      entries in the sysctl tables are unused, and can be
      revmoed.
      
      In addition neigh_sysctl_register has been modified to no longer
      take a strategy argument and it's callers have been modified not
      to pass one.
      
      Cc: "David Miller" <davem@davemloft.net>
      Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
      Cc: netdev@vger.kernel.org
      Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
      f8572d8f
  7. 22 9月, 2009 1 次提交
    • I
      printk: Remove ratelimit.h from kernel.h · 3fff4c42
      Ingo Molnar 提交于
      Decouple kernel.h from ratelimit.h: the global declaration of
      printk's ratelimit_state is not needed, and it leads to messy
      circular dependencies due to ratelimit.h's (new) adding of a
      spinlock_types.h include.
      
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: David S. Miller <davem@davemloft.net>
      LKML-Reference: <new-submission>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      3fff4c42
  8. 27 2月, 2009 1 次提交
  9. 26 11月, 2008 1 次提交
  10. 04 11月, 2008 1 次提交
    • A
      net: '&' redux · 6d9f239a
      Alexey Dobriyan 提交于
      I want to compile out proc_* and sysctl_* handlers totally and
      stub them to NULL depending on config options, however usage of &
      will prevent this, since taking adress of NULL pointer will break
      compilation.
      
      So, drop & in front of every ->proc_handler and every ->strategy
      handler, it was never needed in fact.
      Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      6d9f239a
  11. 26 7月, 2008 1 次提交
    • D
      printk ratelimiting rewrite · 717115e1
      Dave Young 提交于
      All ratelimit user use same jiffies and burst params, so some messages
      (callbacks) will be lost.
      
      For example:
      a call printk_ratelimit(5 * HZ, 1)
      b call printk_ratelimit(5 * HZ, 1) before the 5*HZ timeout of a, then b will
      will be supressed.
      
      - rewrite __ratelimit, and use a ratelimit_state as parameter.  Thanks for
        hints from andrew.
      
      - Add WARN_ON_RATELIMIT, update rcupreempt.h
      
      - remove __printk_ratelimit
      
      - use __ratelimit in net_ratelimit
      Signed-off-by: NDave Young <hidave.darkstar@gmail.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
      Cc: Dave Young <hidave.darkstar@gmail.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      717115e1
  12. 20 5月, 2008 1 次提交
  13. 01 4月, 2008 1 次提交
  14. 29 1月, 2008 5 次提交
  15. 24 10月, 2007 1 次提交
  16. 31 5月, 2007 1 次提交
  17. 25 5月, 2007 1 次提交
    • D
      [XFRM]: Allow packet drops during larval state resolution. · 14e50e57
      David S. Miller 提交于
      The current IPSEC rule resolution behavior we have does not work for a
      lot of people, even though technically it's an improvement from the
      -EAGAIN buisness we had before.
      
      Right now we'll block until the key manager resolves the route.  That
      works for simple cases, but many folks would rather packets get
      silently dropped until the key manager resolves the IPSEC rules.
      
      We can't tell these folks to "set the socket non-blocking" because
      they don't have control over the non-block setting of things like the
      sockets used to resolve DNS deep inside of the resolver libraries in
      libc.
      
      With that in mind I coded up the patch below with some help from
      Herbert Xu which provides packet-drop behavior during larval state
      resolution, controllable via sysctl and off by default.
      
      This lays the framework to either:
      
      1) Make this default at some point or...
      
      2) Move this logic into xfrm{4,6}_policy.c and implement the
         ARP-like resolution queue we've all been dreaming of.
         The idea would be to queue packets to the policy, then
         once the larval state is resolved by the key manager we
         re-resolve the route and push the packets out.  The
         packets would timeout if the rule didn't get resolved
         in a certain amount of time.
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      14e50e57
  18. 26 4月, 2007 1 次提交
  19. 03 12月, 2006 1 次提交
  20. 01 7月, 2006 1 次提交
  21. 21 3月, 2006 1 次提交
  22. 30 8月, 2005 1 次提交
  23. 24 6月, 2005 4 次提交
  24. 17 4月, 2005 1 次提交
    • L
      Linux-2.6.12-rc2 · 1da177e4
      Linus Torvalds 提交于
      Initial git repository build. I'm not bothering with the full history,
      even though we have it. We can create a separate "historical" git
      archive of that later if we want to, and in the meantime it's about
      3.2GB when imported into git - space that would just make the early
      git days unnecessarily complicated, when we don't have a lot of good
      infrastructure for it.
      
      Let it rip!
      1da177e4