1. 12 11月, 2008 1 次提交
    • S
      ring-buffer: buffer record on/off switch · a3583244
      Steven Rostedt 提交于
      Impact: enable/disable ring buffer recording API added
      
      Several kernel developers have requested that there be a way to stop
      recording into the ring buffers with a simple switch that can also
      be enabled from userspace. This patch addes a new kernel API to the
      ring buffers called:
      
       tracing_on()
       tracing_off()
      
      When tracing_off() is called, all ring buffers will not be able to record
      into their buffers.
      
      tracing_on() will enable the ring buffers again.
      
      These two act like an on/off switch. That is, there is no counting of the
      number of times tracing_off or tracing_on has been called.
      
      A new file is added to the debugfs/tracing directory called
      
        tracing_on
      
      This allows for userspace applications to also flip the switch.
      
        echo 0 > debugfs/tracing/tracing_on
      
      disables the tracing.
      
        echo 1 > /debugfs/tracing/tracing_on
      
      enables it.
      
      Note, this does not disable or enable any tracers. It only sets or clears
      a flag that needs to be set in order for the ring buffers to write to
      their buffers. It is a global flag, and affects all ring buffers.
      
      The buffers start out with tracing_on enabled.
      
      There are now three flags that control recording into the buffers:
      
       tracing_on: which affects all ring buffer tracers.
      
       buffer->record_disabled: which affects an allocated buffer, which may be set
           if an anomaly is detected, and tracing is disabled.
      
       cpu_buffer->record_disabled: which is set by tracing_stop() or if an
           anomaly is detected. tracing_start can not reenable this if
           an anomaly occurred.
      
      The userspace debugfs/tracing/tracing_enabled is implemented with
      tracing_stop() but the user space code can not enable it if the kernel
      called tracing_stop().
      
      Userspace can enable the tracing_on even if the kernel disabled it.
      It is just a switch used to stop tracing if a condition was hit.
      tracing_on is not for protecting critical areas in the kernel nor is
      it for stopping tracing if an anomaly occurred. This is because userspace
      can reenable it at any time.
      
      Side effect: With this patch, I discovered a dead variable in ftrace.c
        called tracing_on. This patch removes it.
      Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
      a3583244
  2. 11 11月, 2008 1 次提交
    • T
      libata: revert convert-to-block-tagging patches · 8a8bc223
      Tejun Heo 提交于
      This patch reverts the following three commits which convert libata to
      use block layer tagging.
      
       43a49cbd
       e013e13b
       2fca5ccf
      
      Although using block layer tagging is the right direction, due to the
      tight coupling among tag number, data structure allocation and
      hardware command slot allocation, libata doesn't work correctly with
      the current conversion.
      
      The biggest problem is guaranteeing that tag 0 is always used for
      non-NCQ commands.  Due to the way blk-tag is implemented and how SCSI
      starts and finishes requests, such guarantee can't be made.  I'm not
      sure whether this would actually break any low level driver but it
      doesn't look like a good idea to break such assumption given the
      frailty of ATA controllers.
      
      So, for the time being, keep using the old dumb in-libata qc
      allocation.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Cc: Jens Axobe <jens.axboe@oracle.com>
      Cc: Jeff Garzik <jeff@garzik.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8a8bc223
  3. 10 11月, 2008 3 次提交
  4. 09 11月, 2008 2 次提交
  5. 07 11月, 2008 9 次提交
  6. 06 11月, 2008 4 次提交
    • R
      cpumask: introduce new API, without changing anything · 2d3854a3
      Rusty Russell 提交于
      Impact: introduce new APIs
      
      We want to deprecate cpumasks on the stack, as we are headed for
      gynormous numbers of CPUs.  Eventually, we want to head towards an
      undefined 'struct cpumask' so they can never be declared on stack.
      
      1) New cpumask functions which take pointers instead of copies.
         (cpus_* -> cpumask_*)
      
      2) Several new helpers to reduce requirements for temporary cpumasks
         (cpumask_first_and, cpumask_next_and, cpumask_any_and)
      
      3) Helpers for declaring cpumasks on or offstack for large NR_CPUS
         (cpumask_var_t, alloc_cpumask_var and free_cpumask_var)
      
      4) 'struct cpumask' for explicitness and to mark new-style code.
      
      5) Make iterator functions stop at nr_cpu_ids (a runtime constant),
         not NR_CPUS for time efficiency and for smaller dynamic allocations
         in future.
      
      6) cpumask_copy() so we can allocate less than a full cpumask eventually
         (for alloc_cpumask_var), and so we can eliminate the 'struct cpumask'
         definition eventually.
      
      7) work_on_cpu() helper for doing task on a CPU, rather than saving old
         cpumask for current thread and manipulating it.
      
      8) smp_call_function_many() which is smp_call_function_mask() except
         taking a cpumask pointer.
      
      Note that this patch simply introduces the new functions and leaves
      the obsolescent ones in place.  This is to simplify the transition
      patches.
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      2d3854a3
    • A
      Add round_jiffies_up and related routines · 9c133c46
      Alan Stern 提交于
      This patch (as1158b) adds round_jiffies_up() and friends.  These
      routines work like the analogous round_jiffies() functions, except
      that they will never round down.
      
      The new routines will be useful for timeouts where we don't care
      exactly when the timer expires, provided it doesn't expire too soon.
      Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
      Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
      9c133c46
    • J
      bio: define __BIOVEC_PHYS_MERGEABLE · f92131c3
      Jeremy Fitzhardinge 提交于
      Define __BIOVEC_PHYS_MERGEABLE as the default implementation of
      BIOVEC_PHYS_MERGEABLE, so that its available for reuse within an
      arch-specific definition of BIOVEC_PHYS_MERGEABLE.
      Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
      f92131c3
    • I
      sched: re-tune balancing · 9fcd18c9
      Ingo Molnar 提交于
      Impact: improve wakeup affinity on NUMA systems, tweak SMP systems
      
      Given the fixes+tweaks to the wakeup-buddy code, re-tweak the domain
      balancing defaults on NUMA and SMP systems.
      
      Turn on SD_WAKE_AFFINE which was off on x86 NUMA - there's no reason
      why we would not want to have wakeup affinity across nodes as well.
      (we already do this in the standard NUMA template.)
      
      lat_ctx on a NUMA box is particularly happy about this change:
      
      before:
      
       |   phoenix:~/l> ./lat_ctx -s 0 2
       |   "size=0k ovr=2.60
       |   2 5.70
      
      after:
      
       |   phoenix:~/l> ./lat_ctx -s 0 2
       |   "size=0k ovr=2.65
       |   2 2.07
      
      a 2.75x speedup.
      
      pipe-test is similarly happy about it too:
      
       |  phoenix:~/sched-tests> ./pipe-test
       |   18.26 usecs/loop.
       |   14.70 usecs/loop.
       |   14.38 usecs/loop.
       |   10.55 usecs/loop.              # +WAKE_AFFINE on domain0+domain1
       |   8.63 usecs/loop.
       |   8.59 usecs/loop.
       |   9.03 usecs/loop.
       |   8.94 usecs/loop.
       |   8.96 usecs/loop.
       |   8.63 usecs/loop.
      
      Also:
      
       - disable SD_BALANCE_NEWIDLE on NUMA and SMP domains (keep it for siblings)
       - enable SD_WAKE_BALANCE on SMP domains
      
      Sysbench+postgresql improves all around the board, quite significantly:
      
                 .28-rc3-11474e2c  .28-rc3-11474e2c-tune
      -------------------------------------------------
          1:             571              688    +17.08%
          2:            1236             1206    -2.55%
          4:            2381             2642    +9.89%
          8:            4958             5164    +3.99%
         16:            9580             9574    -0.07%
         32:            7128             8118    +12.20%
         64:            7342             8266    +11.18%
        128:            7342             8064    +8.95%
        256:            7519             7884    +4.62%
        512:            7350             7731    +4.93%
      -------------------------------------------------
        SUM:           55412            59341    +6.62%
      
      So it's a win both for the runup portion, the peak area and the tail.
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      9fcd18c9
  7. 05 11月, 2008 2 次提交
    • E
      [MTD] [NOR] Fix cfi_send_gen_cmd handling of x16 devices in x8 mode (v4) · 467622ef
      Eric W. Biederman 提交于
      For "unlock" cycles to 16bit devices in 8bit compatibility mode we need
      to use the byte addresses 0xaaa and 0x555. These effectively match
      the word address 0x555 and 0x2aa, except the latter has its low bit set.
      
      Most chips don't care about the value of the 'A-1' pin in x8 mode,
      but some -- like the ST M29W320D -- do. So we need to be careful to
      set it where appropriate.
      
      cfi_send_gen_cmd is only ever passed addresses where the low byte
      is 0x00, 0x55 or 0xaa. Of those, only addresses ending 0xaa are
      affected by this patch, by masking in the extra low bit when the device
      is known to be in compatibility mode.
      
      [dwmw2: Do it only when (cmd_ofs & 0xff) == 0xaa]
      v4: Fix  stupid typo in cfi_build_cmd_addr that failed to compile
          I'm writing this patch way to late at night.
      v3: Bring all of the work back into cfi_build_cmd_addr
          including calling of map_bankwidth(map) and cfi_interleave(cfi)
          So every caller doesn't need to.
      v2: Only modified the address if we our device_type is larger than our
          bus width.
      
      Cc: stable@kernel.org
      Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
      Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
      467622ef
    • P
      net: fix packet socket delivery in rx irq handler · 9b22ea56
      Patrick McHardy 提交于
      The changes to deliver hardware accelerated VLAN packets to packet
      sockets (commit bc1d0411) caused a warning for non-NAPI drivers.
      The __vlan_hwaccel_rx() function is called directly from the drivers
      RX function, for non-NAPI drivers that means its still in RX IRQ
      context:
      
      [   27.779463] ------------[ cut here ]------------
      [   27.779509] WARNING: at kernel/softirq.c:136 local_bh_enable+0x37/0x81()
      ...
      [   27.782520]  [<c0264755>] netif_nit_deliver+0x5b/0x75
      [   27.782590]  [<c02bba83>] __vlan_hwaccel_rx+0x79/0x162
      [   27.782664]  [<f8851c1d>] atl1_intr+0x9a9/0xa7c [atl1]
      [   27.782738]  [<c0155b17>] handle_IRQ_event+0x23/0x51
      [   27.782808]  [<c015692e>] handle_edge_irq+0xc2/0x102
      [   27.782878]  [<c0105fd5>] do_IRQ+0x4d/0x64
      
      Split hardware accelerated VLAN reception into two parts to fix this:
      
      - __vlan_hwaccel_rx just stores the VLAN TCI and performs the VLAN
        device lookup, then calls netif_receive_skb()/netif_rx()
      
      - vlan_hwaccel_do_receive(), which is invoked by netif_receive_skb()
        in softirq context, performs the real reception and delivery to
        packet sockets.
      Reported-and-tested-by: NRamon Casellas <ramon.casellas@cttc.es>
      Signed-off-by: NPatrick McHardy <kaber@trash.net>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      9b22ea56
  8. 04 11月, 2008 3 次提交
  9. 03 11月, 2008 2 次提交
  10. 31 10月, 2008 13 次提交
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