1. 13 12月, 2008 1 次提交
    • R
      cpumask: centralize cpu_online_map and cpu_possible_map · 98a79d6a
      Rusty Russell 提交于
      Impact: cleanup
      
      Each SMP arch defines these themselves.  Move them to a central
      location.
      
      Twists:
      1) Some archs (m32, parisc, s390) set possible_map to all 1, so we add a
         CONFIG_INIT_ALL_POSSIBLE for this rather than break them.
      
      2) mips and sparc32 '#define cpu_possible_map phys_cpu_present_map'.
         Those archs simply have phys_cpu_present_map replaced everywhere.
      
      3) Alpha defined cpu_possible_map to cpu_present_map; this is tricky
         so I just manipulate them both in sync.
      
      4) IA64, cris and m32r have gratuitous 'extern cpumask_t cpu_possible_map'
         declarations.
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      Reviewed-by: NGrant Grundler <grundler@parisc-linux.org>
      Tested-by: NTony Luck <tony.luck@intel.com>
      Acked-by: NIngo Molnar <mingo@elte.hu>
      Cc: Mike Travis <travis@sgi.com>
      Cc: ink@jurassic.park.msu.ru
      Cc: rmk@arm.linux.org.uk
      Cc: starvik@axis.com
      Cc: tony.luck@intel.com
      Cc: takata@linux-m32r.org
      Cc: ralf@linux-mips.org
      Cc: grundler@parisc-linux.org
      Cc: paulus@samba.org
      Cc: schwidefsky@de.ibm.com
      Cc: lethal@linux-sh.org
      Cc: wli@holomorphy.com
      Cc: davem@davemloft.net
      Cc: jdike@addtoit.com
      Cc: mingo@redhat.com
      98a79d6a
  2. 14 11月, 2008 1 次提交
  3. 13 11月, 2008 1 次提交
  4. 31 10月, 2008 1 次提交
  5. 23 10月, 2008 1 次提交
  6. 21 10月, 2008 1 次提交
    • T
      PCI: allow quirks to be compiled out · 3d137310
      Thomas Petazzoni 提交于
      This patch adds the CONFIG_PCI_QUIRKS option which allows to remove all
      the PCI quirks, which are not necessarily used on embedded systems when
      PCI is working properly. As this is a size-reduction option, it depends
      on CONFIG_EMBEDDED. It allows to save almost 12 kilobytes of kernel
      code:
      
         text	   data	    bss	    dec	    hex	filename
      1287806	 123596	 212992	1624394	 18c94a	vmlinux.old
      1275854	 123596	 212992	1612442	 189a9a	vmlinux
       -11952       0       0  -11952   -2EB0 +/-
      
      This patch has originally been written by Zwane Mwaikambo
      <zwane@arm.linux.org.uk> and is part of the Linux Tiny project.
      Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
      Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
      3d137310
  7. 20 10月, 2008 1 次提交
    • M
      container freezer: implement freezer cgroup subsystem · dc52ddc0
      Matt Helsley 提交于
      This patch implements a new freezer subsystem in the control groups
      framework.  It provides a way to stop and resume execution of all tasks in
      a cgroup by writing in the cgroup filesystem.
      
      The freezer subsystem in the container filesystem defines a file named
      freezer.state.  Writing "FROZEN" to the state file will freeze all tasks
      in the cgroup.  Subsequently writing "RUNNING" will unfreeze the tasks in
      the cgroup.  Reading will return the current state.
      
      * Examples of usage :
      
         # mkdir /containers/freezer
         # mount -t cgroup -ofreezer freezer  /containers
         # mkdir /containers/0
         # echo $some_pid > /containers/0/tasks
      
      to get status of the freezer subsystem :
      
         # cat /containers/0/freezer.state
         RUNNING
      
      to freeze all tasks in the container :
      
         # echo FROZEN > /containers/0/freezer.state
         # cat /containers/0/freezer.state
         FREEZING
         # cat /containers/0/freezer.state
         FROZEN
      
      to unfreeze all tasks in the container :
      
         # echo RUNNING > /containers/0/freezer.state
         # cat /containers/0/freezer.state
         RUNNING
      
      This is the basic mechanism which should do the right thing for user space
      task in a simple scenario.
      
      It's important to note that freezing can be incomplete.  In that case we
      return EBUSY.  This means that some tasks in the cgroup are busy doing
      something that prevents us from completely freezing the cgroup at this
      time.  After EBUSY, the cgroup will remain partially frozen -- reflected
      by freezer.state reporting "FREEZING" when read.  The state will remain
      "FREEZING" until one of these things happens:
      
      	1) Userspace cancels the freezing operation by writing "RUNNING" to
      		the freezer.state file
      	2) Userspace retries the freezing operation by writing "FROZEN" to
      		the freezer.state file (writing "FREEZING" is not legal
      		and returns EIO)
      	3) The tasks that blocked the cgroup from entering the "FROZEN"
      		state disappear from the cgroup's set of tasks.
      
      [akpm@linux-foundation.org: coding-style fixes]
      [akpm@linux-foundation.org: export thaw_process]
      Signed-off-by: NCedric Le Goater <clg@fr.ibm.com>
      Signed-off-by: NMatt Helsley <matthltc@us.ibm.com>
      Acked-by: NSerge E. Hallyn <serue@us.ibm.com>
      Tested-by: NMatt Helsley <matthltc@us.ibm.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      dc52ddc0
  8. 17 10月, 2008 1 次提交
  9. 14 10月, 2008 3 次提交
    • I
      tracing: clean up tracepoints kconfig structure · 5f87f112
      Ingo Molnar 提交于
      do not expose users to CONFIG_TRACEPOINTS - tracers can select it
      just fine.
      
      update ftrace to select CONFIG_TRACEPOINTS.
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      5f87f112
    • I
      tracing: disable tracepoints by default · fa340d9c
      Ingo Molnar 提交于
      while it's arguably low overhead, we dont enable new features by default.
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      fa340d9c
    • M
      tracing: Kernel Tracepoints · 97e1c18e
      Mathieu Desnoyers 提交于
      Implementation of kernel tracepoints. Inspired from the Linux Kernel
      Markers. Allows complete typing verification by declaring both tracing
      statement inline functions and probe registration/unregistration static
      inline functions within the same macro "DEFINE_TRACE". No format string
      is required. See the tracepoint Documentation and Samples patches for
      usage examples.
      
      Taken from the documentation patch :
      
      "A tracepoint placed in code provides a hook to call a function (probe)
      that you can provide at runtime. A tracepoint can be "on" (a probe is
      connected to it) or "off" (no probe is attached). When a tracepoint is
      "off" it has no effect, except for adding a tiny time penalty (checking
      a condition for a branch) and space penalty (adding a few bytes for the
      function call at the end of the instrumented function and adds a data
      structure in a separate section).  When a tracepoint is "on", the
      function you provide is called each time the tracepoint is executed, in
      the execution context of the caller. When the function provided ends its
      execution, it returns to the caller (continuing from the tracepoint
      site).
      
      You can put tracepoints at important locations in the code. They are
      lightweight hooks that can pass an arbitrary number of parameters, which
      prototypes are described in a tracepoint declaration placed in a header
      file."
      
      Addition and removal of tracepoints is synchronized by RCU using the
      scheduler (and preempt_disable) as guarantees to find a quiescent state
      (this is really RCU "classic"). The update side uses rcu_barrier_sched()
      with call_rcu_sched() and the read/execute side uses
      "preempt_disable()/preempt_enable()".
      
      We make sure the previous array containing probes, which has been
      scheduled for deletion by the rcu callback, is indeed freed before we
      proceed to the next update. It therefore limits the rate of modification
      of a single tracepoint to one update per RCU period. The objective here
      is to permit fast batch add/removal of probes on _different_
      tracepoints.
      
      Changelog :
      - Use #name ":" #proto as string to identify the tracepoint in the
        tracepoint table. This will make sure not type mismatch happens due to
        connexion of a probe with the wrong type to a tracepoint declared with
        the same name in a different header.
      - Add tracepoint_entry_free_old.
      - Change __TO_TRACE to get rid of the 'i' iterator.
      
      Masami Hiramatsu <mhiramat@redhat.com> :
      Tested on x86-64.
      
      Performance impact of a tracepoint : same as markers, except that it
      adds about 70 bytes of instructions in an unlikely branch of each
      instrumented function (the for loop, the stack setup and the function
      call). It currently adds a memory read, a test and a conditional branch
      at the instrumentation site (in the hot path). Immediate values will
      eventually change this into a load immediate, test and branch, which
      removes the memory read which will make the i-cache impact smaller
      (changing the memory read for a load immediate removes 3-4 bytes per
      site on x86_32 (depending on mov prefixes), or 7-8 bytes on x86_64, it
      also saves the d-cache hit).
      
      About the performance impact of tracepoints (which is comparable to
      markers), even without immediate values optimizations, tests done by
      Hideo Aoki on ia64 show no regression. His test case was using hackbench
      on a kernel where scheduler instrumentation (about 5 events in code
      scheduler code) was added.
      
      Quoting Hideo Aoki about Markers :
      
      I evaluated overhead of kernel marker using linux-2.6-sched-fixes git
      tree, which includes several markers for LTTng, using an ia64 server.
      
      While the immediate trace mark feature isn't implemented on ia64, there
      is no major performance regression. So, I think that we don't have any
      issues to propose merging marker point patches into Linus's tree from
      the viewpoint of performance impact.
      
      I prepared two kernels to evaluate. The first one was compiled without
      CONFIG_MARKERS. The second one was enabled CONFIG_MARKERS.
      
      I downloaded the original hackbench from the following URL:
      http://devresources.linux-foundation.org/craiger/hackbench/src/hackbench.c
      
      I ran hackbench 5 times in each condition and calculated the average and
      difference between the kernels.
      
          The parameter of hackbench: every 50 from 50 to 800
          The number of CPUs of the server: 2, 4, and 8
      
      Below is the results. As you can see, major performance regression
      wasn't found in any case. Even if number of processes increases,
      differences between marker-enabled kernel and marker- disabled kernel
      doesn't increase. Moreover, if number of CPUs increases, the differences
      doesn't increase either.
      
      Curiously, marker-enabled kernel is better than marker-disabled kernel
      in more than half cases, although I guess it comes from the difference
      of memory access pattern.
      
      * 2 CPUs
      
      Number of | without      | with         | diff     | diff    |
      processes | Marker [Sec] | Marker [Sec] |   [Sec]  |   [%]   |
      --------------------------------------------------------------
             50 |      4.811   |       4.872  |  +0.061  |  +1.27  |
            100 |      9.854   |      10.309  |  +0.454  |  +4.61  |
            150 |     15.602   |      15.040  |  -0.562  |  -3.6   |
            200 |     20.489   |      20.380  |  -0.109  |  -0.53  |
            250 |     25.798   |      25.652  |  -0.146  |  -0.56  |
            300 |     31.260   |      30.797  |  -0.463  |  -1.48  |
            350 |     36.121   |      35.770  |  -0.351  |  -0.97  |
            400 |     42.288   |      42.102  |  -0.186  |  -0.44  |
            450 |     47.778   |      47.253  |  -0.526  |  -1.1   |
            500 |     51.953   |      52.278  |  +0.325  |  +0.63  |
            550 |     58.401   |      57.700  |  -0.701  |  -1.2   |
            600 |     63.334   |      63.222  |  -0.112  |  -0.18  |
            650 |     68.816   |      68.511  |  -0.306  |  -0.44  |
            700 |     74.667   |      74.088  |  -0.579  |  -0.78  |
            750 |     78.612   |      79.582  |  +0.970  |  +1.23  |
            800 |     85.431   |      85.263  |  -0.168  |  -0.2   |
      --------------------------------------------------------------
      
      * 4 CPUs
      
      Number of | without      | with         | diff     | diff    |
      processes | Marker [Sec] | Marker [Sec] |   [Sec]  |   [%]   |
      --------------------------------------------------------------
             50 |      2.586   |       2.584  |  -0.003  |  -0.1   |
            100 |      5.254   |       5.283  |  +0.030  |  +0.56  |
            150 |      8.012   |       8.074  |  +0.061  |  +0.76  |
            200 |     11.172   |      11.000  |  -0.172  |  -1.54  |
            250 |     13.917   |      14.036  |  +0.119  |  +0.86  |
            300 |     16.905   |      16.543  |  -0.362  |  -2.14  |
            350 |     19.901   |      20.036  |  +0.135  |  +0.68  |
            400 |     22.908   |      23.094  |  +0.186  |  +0.81  |
            450 |     26.273   |      26.101  |  -0.172  |  -0.66  |
            500 |     29.554   |      29.092  |  -0.461  |  -1.56  |
            550 |     32.377   |      32.274  |  -0.103  |  -0.32  |
            600 |     35.855   |      35.322  |  -0.533  |  -1.49  |
            650 |     39.192   |      38.388  |  -0.804  |  -2.05  |
            700 |     41.744   |      41.719  |  -0.025  |  -0.06  |
            750 |     45.016   |      44.496  |  -0.520  |  -1.16  |
            800 |     48.212   |      47.603  |  -0.609  |  -1.26  |
      --------------------------------------------------------------
      
      * 8 CPUs
      
      Number of | without      | with         | diff     | diff    |
      processes | Marker [Sec] | Marker [Sec] |   [Sec]  |   [%]   |
      --------------------------------------------------------------
             50 |      2.094   |       2.072  |  -0.022  |  -1.07  |
            100 |      4.162   |       4.273  |  +0.111  |  +2.66  |
            150 |      6.485   |       6.540  |  +0.055  |  +0.84  |
            200 |      8.556   |       8.478  |  -0.078  |  -0.91  |
            250 |     10.458   |      10.258  |  -0.200  |  -1.91  |
            300 |     12.425   |      12.750  |  +0.325  |  +2.62  |
            350 |     14.807   |      14.839  |  +0.032  |  +0.22  |
            400 |     16.801   |      16.959  |  +0.158  |  +0.94  |
            450 |     19.478   |      19.009  |  -0.470  |  -2.41  |
            500 |     21.296   |      21.504  |  +0.208  |  +0.98  |
            550 |     23.842   |      23.979  |  +0.137  |  +0.57  |
            600 |     26.309   |      26.111  |  -0.198  |  -0.75  |
            650 |     28.705   |      28.446  |  -0.259  |  -0.9   |
            700 |     31.233   |      31.394  |  +0.161  |  +0.52  |
            750 |     34.064   |      33.720  |  -0.344  |  -1.01  |
            800 |     36.320   |      36.114  |  -0.206  |  -0.57  |
      --------------------------------------------------------------
      Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
      Acked-by: NMasami Hiramatsu <mhiramat@redhat.com>
      Acked-by: N'Peter Zijlstra' <peterz@infradead.org>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      97e1c18e
  10. 10 10月, 2008 1 次提交
  11. 17 8月, 2008 1 次提交
  12. 07 8月, 2008 1 次提交
  13. 01 8月, 2008 1 次提交
  14. 26 7月, 2008 2 次提交
  15. 22 7月, 2008 2 次提交
  16. 30 6月, 2008 1 次提交
  17. 26 5月, 2008 1 次提交
    • S
      Kconfig: introduce ARCH_DEFCONFIG to DEFCONFIG_LIST · 73531905
      Sam Ravnborg 提交于
      init/Kconfig contains a list of configs that are searched
      for if 'make *config' are used with no .config present.
      Extend this list to look at the config identified by
      ARCH_DEFCONFIG.
      
      With this change we now try the defconfig targets last.
      
      This fixes a regression reported
      by: Linus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      73531905
  18. 09 5月, 2008 1 次提交
  19. 07 5月, 2008 1 次提交
  20. 06 5月, 2008 2 次提交
  21. 05 5月, 2008 1 次提交
    • L
      Make forced module loading optional · 826e4506
      Linus Torvalds 提交于
      The kernel module loader used to be much too happy to allow loading of
      modules for the wrong kernel version by default.  For example, if you
      had MODVERSIONS enabled, but tried to load a module with no version
      info, it would happily load it and taint the kernel - whether it was
      likely to actually work or not!
      
      Generally, such forced module loading should be considered a really
      really bad idea, so make it conditional on a new config option
      (MODULE_FORCE_LOAD), and make it default to off.
      
      If somebody really wants to force module loads, that's their problem,
      but we should not encourage it.  Especially as it happened to me by
      mistake (ie regular unversioned Fedora modules getting loaded) causing
      lots of strange behavior.
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      826e4506
  22. 02 5月, 2008 1 次提交
  23. 29 4月, 2008 6 次提交
    • H
      sysctl: allow embedded targets to disable sysctl_check.c · 88f458e4
      Holger Schurig 提交于
      Disable sysctl_check.c for embedded targets. This saves about about 11 kB
      in .text and another 11 kB in .data on a PXA255 embedded platform.
      Signed-off-by: NHolger Schurig <hs4233@mail.mn-solutions.de>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      88f458e4
    • B
      cgroups: add an owner to the mm_struct · cf475ad2
      Balbir Singh 提交于
      Remove the mem_cgroup member from mm_struct and instead adds an owner.
      
      This approach was suggested by Paul Menage.  The advantage of this approach
      is that, once the mm->owner is known, using the subsystem id, the cgroup
      can be determined.  It also allows several control groups that are
      virtually grouped by mm_struct, to exist independent of the memory
      controller i.e., without adding mem_cgroup's for each controller, to
      mm_struct.
      
      A new config option CONFIG_MM_OWNER is added and the memory resource
      controller selects this config option.
      
      This patch also adds cgroup callbacks to notify subsystems when mm->owner
      changes.  The mm_cgroup_changed callback is called with the task_lock() of
      the new task held and is called just prior to changing the mm->owner.
      
      I am indebted to Paul Menage for the several reviews of this patchset and
      helping me make it lighter and simpler.
      
      This patch was tested on a powerpc box, it was compiled with both the
      MM_OWNER config turned on and off.
      
      After the thread group leader exits, it's moved to init_css_state by
      cgroup_exit(), thus all future charges from runnings threads would be
      redirected to the init_css_set's subsystem.
      Signed-off-by: NBalbir Singh <balbir@linux.vnet.ibm.com>
      Cc: Pavel Emelianov <xemul@openvz.org>
      Cc: Hugh Dickins <hugh@veritas.com>
      Cc: Sudhir Kumar <skumar@linux.vnet.ibm.com>
      Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
      Cc: Hirokazu Takahashi <taka@valinux.co.jp>
      Cc: David Rientjes <rientjes@google.com>,
      Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
      Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Acked-by: NPekka Enberg <penberg@cs.helsinki.fi>
      Reviewed-by: NPaul Menage <menage@google.com>
      Cc: Oleg Nesterov <oleg@tv-sign.ru>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      cf475ad2
    • S
      cgroups: implement device whitelist · 08ce5f16
      Serge E. Hallyn 提交于
      Implement a cgroup to track and enforce open and mknod restrictions on device
      files.  A device cgroup associates a device access whitelist with each cgroup.
       A whitelist entry has 4 fields.  'type' is a (all), c (char), or b (block).
      'all' means it applies to all types and all major and minor numbers.  Major
      and minor are either an integer or * for all.  Access is a composition of r
      (read), w (write), and m (mknod).
      
      The root device cgroup starts with rwm to 'all'.  A child devcg gets a copy of
      the parent.  Admins can then remove devices from the whitelist or add new
      entries.  A child cgroup can never receive a device access which is denied its
      parent.  However when a device access is removed from a parent it will not
      also be removed from the child(ren).
      
      An entry is added using devices.allow, and removed using
      devices.deny.  For instance
      
      	echo 'c 1:3 mr' > /cgroups/1/devices.allow
      
      allows cgroup 1 to read and mknod the device usually known as
      /dev/null.  Doing
      
      	echo a > /cgroups/1/devices.deny
      
      will remove the default 'a *:* mrw' entry.
      
      CAP_SYS_ADMIN is needed to change permissions or move another task to a new
      cgroup.  A cgroup may not be granted more permissions than the cgroup's parent
      has.  Any task can move itself between cgroups.  This won't be sufficient, but
      we can decide the best way to adequately restrict movement later.
      
      [akpm@linux-foundation.org: coding-style fixes]
      [akpm@linux-foundation.org: fix may-be-used-uninitialized warning]
      Signed-off-by: NSerge E. Hallyn <serue@us.ibm.com>
      Acked-by: NJames Morris <jmorris@namei.org>
      Looks-good-to: Pavel Emelyanov <xemul@openvz.org>
      Cc: Daniel Hokka Zakrisson <daniel@hozac.com>
      Cc: Li Zefan <lizf@cn.fujitsu.com>
      Cc: Paul Menage <menage@google.com>
      Cc: Balbir Singh <balbir@in.ibm.com>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      08ce5f16
    • P
      CGroup API files: make CGROUP_DEBUG default to off · 418d7d87
      Paul Menage 提交于
      The cgroup debug subsystem isn't generally useful for users.  It should
      default to "n".
      Signed-off-by: NPaul Menage <menage@google.com>
      Cc: "Li Zefan" <lizf@cn.fujitsu.com>
      Cc: Balbir Singh <balbir@in.ibm.com>
      Cc: Paul Jackson <pj@sgi.com>
      Cc: Pavel Emelyanov <xemul@openvz.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      418d7d87
    • A
      let LOG_BUF_SHIFT default to 17 · f17a32e9
      Adrian Bunk 提交于
      16 kB is often no longer enough for a normal boot of an UP system.
      
      And even less when people e.g. use suspend.
      
      17 seems to be a more reasonable default for current kernels on current
      hardware (it's just the default, anyone who is memory limited can still lower
      it).
      Signed-off-by: NAdrian Bunk <bunk@kernel.org>
      Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f17a32e9
    • I
      make CC_OPTIMIZE_FOR_SIZE non-experimental · 96fffeb4
      Ingo Molnar 提交于
      this option has been the default on a wide range of distributions
      for a long time - time to make it non-experimental.
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      96fffeb4
  24. 27 4月, 2008 1 次提交
  25. 20 4月, 2008 1 次提交
  26. 14 4月, 2008 1 次提交
    • C
      slub: No need for per node slab counters if !SLUB_DEBUG · 0f389ec6
      Christoph Lameter 提交于
      The per node counters are used mainly for showing data through the sysfs API.
      If that API is not compiled in then there is no point in keeping track of this
      data. Disable counters for the number of slabs and the number of total slabs
      if !SLUB_DEBUG. Incrementing the per node counters is also accessing a
      potentially contended cacheline so this could actually be a performance
      benefit to embedded systems.
      
      SLABINFO support is also affected. It now must depends on SLUB_DEBUG (which
      is on by default).
      
      Patch also avoids a check for a NULL kmem_cache_node pointer in new_slab()
      if the system is not compiled with NUMA support.
      
      [penberg@cs.helsinki.fi: fix oops and move ->nr_slabs into CONFIG_SLUB_DEBUG]
      Signed-off-by: NChristoph Lameter <clameter@sgi.com>
      Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
      0f389ec6
  27. 11 3月, 2008 1 次提交
    • P
      rcu: move PREEMPT_RCU config option back under PREEMPT · 21bbb39c
      Paul E. McKenney 提交于
      The original preemptible-RCU patch put the choice between classic and
      preemptible RCU into kernel/Kconfig.preempt, which resulted in build failures
      on machines not supporting CONFIG_PREEMPT.  This choice was therefore moved to
      init/Kconfig, which worked, but placed the choice between classic and
      preemptible RCU at the top level, a very obtuse choice indeed.
      
      This patch changes from the Kconfig "choice" mechanism to a pair of booleans,
      only one of which (CONFIG_PREEMPT_RCU) is user-visible, and is located in
      kernel/Kconfig.preempt, where one would expect it to be.  The other
      (CONFIG_CLASSIC_RCU) is in init/Kconfig so that it is available to all
      architectures, hopefully avoiding build breakage.  Thanks to Roman Zippel for
      suggesting this approach.
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Acked-by: NSteven Rostedt <rostedt@goodmis.org>
      Cc: Dipankar Sarma <dipankar@in.ibm.com>
      Cc: Josh Triplett <josh@freedesktop.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Roman Zippel <zippel@linux-m68k.org>
      Cc: Sam Ravnborg <sam@ravnborg.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      21bbb39c
  28. 05 3月, 2008 3 次提交