1. 07 4月, 2009 3 次提交
  2. 03 4月, 2009 3 次提交
  3. 30 3月, 2009 2 次提交
  4. 11 3月, 2009 1 次提交
  5. 03 3月, 2009 2 次提交
  6. 21 2月, 2009 1 次提交
    • F
      tracing/markers: make markers select tracepoints · 91f73f90
      Frederic Weisbecker 提交于
      Sometimes it happens that KConfig dependencies are not handled
      like in the following scenario:
      
      - config A
         bool
      
      - config B
         bool
         depends on A
      
      - config C
         bool
         select B
      
      If one selects C, then it will select B without checking its
      dependency to A, if A hasn't been selected elsewhere, it will
      result in a build failure.
      
      This is what happens on the following build error:
      
       kernel/built-in.o: In function `marker_update_probe_range':
       (.text+0x52f64): undefined reference to `tracepoint_probe_register_noupdate'
       kernel/built-in.o: In function `marker_update_probe_range':
       (.text+0x52f74): undefined reference to `tracepoint_probe_unregister_noupdate'
       kernel/built-in.o: In function `marker_update_probe_range':
       (.text+0x52fb9): undefined reference to `tracepoint_probe_unregister_noupdate'
       kernel/built-in.o: In function `marker_update_probes':
       marker.c:(.text+0x530ba): undefined reference to `tracepoint_probe_update_all'
      
      CONFIG_KVM_TRACE will select CONFIG_MARKER, but the latter
      depends on CONFIG_TRACEPOINTS which will not be selected.
      Reported-by: NIngo Molnar <mingo@elte.hu>
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      91f73f90
  7. 27 1月, 2009 1 次提交
  8. 16 1月, 2009 4 次提交
  9. 15 1月, 2009 1 次提交
  10. 09 1月, 2009 3 次提交
  11. 07 1月, 2009 2 次提交
  12. 05 1月, 2009 3 次提交
  13. 25 12月, 2008 1 次提交
    • I
      rcu: provide RCU options on non-preempt architectures too · 12d79baf
      Ingo Molnar 提交于
      Impact: build fix
      
      Some old architectures still do not use kernel/Kconfig.preempt, so the
      moving of the RCU options there broke their build:
      
       In file included from /home/mingo/tip/include/linux/sem.h:81,
                       from /home/mingo/tip/include/linux/sched.h:69,
                       from /home/mingo/tip/arch/alpha/kernel/asm-offsets.c:9:
       /home/mingo/tip/include/linux/rcupdate.h:62:2: error: #error "Unknown RCU implementation specified to kernel configuration"
      
      Move these options back to init/Kconfig, which every architecture
      includes.
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      12d79baf
  14. 20 12月, 2008 1 次提交
    • J
      allow stripping of generated symbols under CONFIG_KALLSYMS_ALL · 9bb48247
      Jan Beulich 提交于
      Building upon parts of the module stripping patch, this patch
      introduces similar stripping for vmlinux when CONFIG_KALLSYMS_ALL=y.
      Using CONFIG_KALLSYMS_STRIP_GENERATED reduces the overhead of
      CONFIG_KALLSYMS_ALL from 245k/310k to 65k/80k for the (i386/x86-64)
      kernels I tested with.
      
      The patch also does away with the need to special case the kallsyms-
      internal symbols by making them available even in the first linking
      stage.
      
      While it is a generated file, the patch includes the changes to
      scripts/genksyms/keywords.c_shipped, as I'm unsure what the procedure
      here is.
      Signed-off-by: NJan Beulich <jbeulich@novell.com>
      Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
      9bb48247
  15. 19 12月, 2008 1 次提交
    • P
      "Tree RCU": scalable classic RCU implementation · 64db4cff
      Paul E. McKenney 提交于
      This patch fixes a long-standing performance bug in classic RCU that
      results in massive internal-to-RCU lock contention on systems with
      more than a few hundred CPUs.  Although this patch creates a separate
      flavor of RCU for ease of review and patch maintenance, it is intended
      to replace classic RCU.
      
      This patch still handles stress better than does mainline, so I am still
      calling it ready for inclusion.  This patch is against the -tip tree.
      Nevertheless, experience on an actual 1000+ CPU machine would still be
      most welcome.
      
      Most of the changes noted below were found while creating an rcutiny
      (which should permit ejecting the current rcuclassic) and while doing
      detailed line-by-line documentation.
      
      Updates from v9 (http://lkml.org/lkml/2008/12/2/334):
      
      o	Fixes from remainder of line-by-line code walkthrough,
      	including comment spelling, initialization, undesirable
      	narrowing due to type conversion, removing redundant memory
      	barriers, removing redundant local-variable initialization,
      	and removing redundant local variables.
      
      	I do not believe that any of these fixes address the CPU-hotplug
      	issues that Andi Kleen was seeing, but please do give it a whirl
      	in case the machine is smarter than I am.
      
      	A writeup from the walkthrough may be found at the following
      	URL, in case you are suffering from terminal insomnia or
      	masochism:
      
      	http://www.kernel.org/pub/linux/kernel/people/paulmck/tmp/rcutree-walkthrough.2008.12.16a.pdf
      
      o	Made rcutree tracing use seq_file, as suggested some time
      	ago by Lai Jiangshan.
      
      o	Added a .csv variant of the rcudata debugfs trace file, to allow
      	people having thousands of CPUs to drop the data into
      	a spreadsheet.	Tested with oocalc and gnumeric.  Updated
      	documentation to suit.
      
      Updates from v8 (http://lkml.org/lkml/2008/11/15/139):
      
      o	Fix a theoretical race between grace-period initialization and
      	force_quiescent_state() that could occur if more than three
      	jiffies were required to carry out the grace-period
      	initialization.  Which it might, if you had enough CPUs.
      
      o	Apply Ingo's printk-standardization patch.
      
      o	Substitute local variables for repeated accesses to global
      	variables.
      
      o	Fix comment misspellings and redundant (but harmless) increments
      	of ->n_rcu_pending (this latter after having explicitly added it).
      
      o	Apply checkpatch fixes.
      
      Updates from v7 (http://lkml.org/lkml/2008/10/10/291):
      
      o	Fixed a number of problems noted by Gautham Shenoy, including
      	the cpu-stall-detection bug that he was having difficulty
      	convincing me was real.  ;-)
      
      o	Changed cpu-stall detection to wait for ten seconds rather than
      	three in order to reduce false positive, as suggested by Ingo
      	Molnar.
      
      o	Produced a design document (http://lwn.net/Articles/305782/).
      	The act of writing this document uncovered a number of both
      	theoretical and "here and now" bugs as noted below.
      
      o	Fix dynticks_nesting accounting confusion, simplify WARN_ON()
      	condition, fix kerneldoc comments, and add memory barriers
      	in dynticks interface functions.
      
      o	Add more data to tracing.
      
      o	Remove unused "rcu_barrier" field from rcu_data structure.
      
      o	Count calls to rcu_pending() from scheduling-clock interrupt
      	to use as a surrogate timebase should jiffies stop counting.
      
      o	Fix a theoretical race between force_quiescent_state() and
      	grace-period initialization.  Yes, initialization does have to
      	go on for some jiffies for this race to occur, but given enough
      	CPUs...
      
      Updates from v6 (http://lkml.org/lkml/2008/9/23/448):
      
      o	Fix a number of checkpatch.pl complaints.
      
      o	Apply review comments from Ingo Molnar and Lai Jiangshan
      	on the stall-detection code.
      
      o	Fix several bugs in !CONFIG_SMP builds.
      
      o	Fix a misspelled config-parameter name so that RCU now announces
      	at boot time if stall detection is configured.
      
      o	Run tests on numerous combinations of configurations parameters,
      	which after the fixes above, now build and run correctly.
      
      Updates from v5 (http://lkml.org/lkml/2008/9/15/92, bad subject line):
      
      o	Fix a compiler error in the !CONFIG_FANOUT_EXACT case (blew a
      	changeset some time ago, and finally got around to retesting
      	this option).
      
      o	Fix some tracing bugs in rcupreempt that caused incorrect
      	totals to be printed.
      
      o	I now test with a more brutal random-selection online/offline
      	script (attached).  Probably more brutal than it needs to be
      	on the people reading it as well, but so it goes.
      
      o	A number of optimizations and usability improvements:
      
      	o	Make rcu_pending() ignore the grace-period timeout when
      		there is no grace period in progress.
      
      	o	Make force_quiescent_state() avoid going for a global
      		lock in the case where there is no grace period in
      		progress.
      
      	o	Rearrange struct fields to improve struct layout.
      
      	o	Make call_rcu() initiate a grace period if RCU was
      		idle, rather than waiting for the next scheduling
      		clock interrupt.
      
      	o	Invoke rcu_irq_enter() and rcu_irq_exit() only when
      		idle, as suggested by Andi Kleen.  I still don't
      		completely trust this change, and might back it out.
      
      	o	Make CONFIG_RCU_TRACE be the single config variable
      		manipulated for all forms of RCU, instead of the prior
      		confusion.
      
      	o	Document tracing files and formats for both rcupreempt
      		and rcutree.
      
      Updates from v4 for those missing v5 given its bad subject line:
      
      o	Separated dynticks interface so that NMIs and irqs call separate
      	functions, greatly simplifying it.  In particular, this code
      	no longer requires a proof of correctness.  ;-)
      
      o	Separated dynticks state out into its own per-CPU structure,
      	avoiding the duplicated accounting.
      
      o	The case where a dynticks-idle CPU runs an irq handler that
      	invokes call_rcu() is now correctly handled, forcing that CPU
      	out of dynticks-idle mode.
      
      o	Review comments have been applied (thank you all!!!).
      	For but one example, fixed the dynticks-ordering issue that
      	Manfred pointed out, saving me much debugging.  ;-)
      
      o	Adjusted rcuclassic and rcupreempt to handle dynticks changes.
      
      Attached is an updated patch to Classic RCU that applies a hierarchy,
      greatly reducing the contention on the top-level lock for large machines.
      This passes 10-hour concurrent rcutorture and online-offline testing on
      128-CPU ppc64 without dynticks enabled, and exposes some timekeeping
      bugs in presence of dynticks (exciting working on a system where
      "sleep 1" hangs until interrupted...), which were fixed in the
      2.6.27 kernel.  It is getting more reliable than mainline by some
      measures, so the next version will be against -tip for inclusion.
      See also Manfred Spraul's recent patches (or his earlier work from
      2004 at http://marc.info/?l=linux-kernel&m=108546384711797&w=2).
      We will converge onto a common patch in the fullness of time, but are
      currently exploring different regions of the design space.  That said,
      I have already gratefully stolen quite a few of Manfred's ideas.
      
      This patch provides CONFIG_RCU_FANOUT, which controls the bushiness
      of the RCU hierarchy.  Defaults to 32 on 32-bit machines and 64 on
      64-bit machines.  If CONFIG_NR_CPUS is less than CONFIG_RCU_FANOUT,
      there is no hierarchy.  By default, the RCU initialization code will
      adjust CONFIG_RCU_FANOUT to balance the hierarchy, so strongly NUMA
      architectures may choose to set CONFIG_RCU_FANOUT_EXACT to disable
      this balancing, allowing the hierarchy to be exactly aligned to the
      underlying hardware.  Up to two levels of hierarchy are permitted
      (in addition to the root node), allowing up to 16,384 CPUs on 32-bit
      systems and up to 262,144 CPUs on 64-bit systems.  I just know that I
      am going to regret saying this, but this seems more than sufficient
      for the foreseeable future.  (Some architectures might wish to set
      CONFIG_RCU_FANOUT=4, which would limit such architectures to 64 CPUs.
      If this becomes a real problem, additional levels can be added, but I
      doubt that it will make a significant difference on real hardware.)
      
      In the common case, a given CPU will manipulate its private rcu_data
      structure and the rcu_node structure that it shares with its immediate
      neighbors.  This can reduce both lock and memory contention by multiple
      orders of magnitude, which should eliminate the need for the strange
      manipulations that are reported to be required when running Linux on
      very large systems.
      
      Some shortcomings:
      
      o	More bugs will probably surface as a result of an ongoing
      	line-by-line code inspection.
      
      	Patches will be provided as required.
      
      o	There are probably hangs, rcutorture failures, &c.  Seems
      	quite stable on a 128-CPU machine, but that is kind of small
      	compared to 4096 CPUs.  However, seems to do better than
      	mainline.
      
      	Patches will be provided as required.
      
      o	The memory footprint of this version is several KB larger
      	than rcuclassic.
      
      	A separate UP-only rcutiny patch will be provided, which will
      	reduce the memory footprint significantly, even compared
      	to the old rcuclassic.  One such patch passes light testing,
      	and has a memory footprint smaller even than rcuclassic.
      	Initial reaction from various embedded guys was "it is not
      	worth it", so am putting it aside.
      
      Credits:
      
      o	Manfred Spraul for ideas, review comments, and bugs spotted,
      	as well as some good friendly competition.  ;-)
      
      o	Josh Triplett, Ingo Molnar, Peter Zijlstra, Mathieu Desnoyers,
      	Lai Jiangshan, Andi Kleen, Andy Whitcroft, and Andrew Morton
      	for reviews and comments.
      
      o	Thomas Gleixner for much-needed help with some timer issues
      	(see patches below).
      
      o	Jon M. Tollefson, Tim Pepper, Andrew Theurer, Jose R. Santos,
      	Andy Whitcroft, Darrick Wong, Nishanth Aravamudan, Anton
      	Blanchard, Dave Kleikamp, and Nathan Lynch for keeping machines
      	alive despite my heavy abuse^Wtesting.
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      64db4cff
  16. 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
  17. 16 11月, 2008 1 次提交
  18. 14 11月, 2008 1 次提交
  19. 13 11月, 2008 1 次提交
  20. 31 10月, 2008 1 次提交
  21. 23 10月, 2008 1 次提交
  22. 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
  23. 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
  24. 17 10月, 2008 1 次提交
  25. 14 10月, 2008 2 次提交