1. 28 Nov, 2012 1 commit
  2. 30 Sep, 2012 3 commits
  3. 26 Sep, 2012 2 commits
    • Heiko Carstens's avatar
      s390/process: add missing header include · f6e38691
      Heiko Carstens authored
      
      
      Add appropriate header file:
      
      arch/s390/kernel/process.c:327:15: warning: symbol 'arch_align_stack' was not declared.
      Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      f6e38691
    • Jan Glauber's avatar
      s390: add support for runtime instrumentation · e4b8b3f3
      Jan Glauber authored
      
      
      Allow user-space threads to use runtime instrumentation (RI). To enable RI
      for a thread there is a new s390 specific system call, sys_s390_runtime_instr,
      that takes as parameter a realtime signal number. If the RI facility is
      available the system call sets up a control block for the calling thread with
      the appropriate permissions for the thread to modify the control block.
      
      The user-space thread can then use the store and modify RI instructions to
      alter the control block and start/stop the instrumentation via RION/RIOFF.
      
      If the user specified program buffer runs full RI triggers an external
      interrupt. The external interrupt is translated to a real-time signal that
      is delivered to the thread that enabled RI on that CPU. The number of
      the real-time signal is the number specified in the RI system call. So,
      user-space can select any available real-time signal number in case the
      application itself uses real-time signals for other purposes.
      
      The kernel saves the RI control blocks on task switch only if the running
      thread was enabled for RI. Therefore, the performance impact on task switch
      should be negligible if RI is not used.
      
      RI is only enabled for user-space mode and is disabled for the supervisor
      state.
      Reviewed-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      Signed-off-by: default avatarJan Glauber <jang@linux.vnet.ibm.com>
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      e4b8b3f3
  4. 20 Jul, 2012 2 commits
    • Martin Schwidefsky's avatar
      s390/vtimer: rework virtual timer interface · 27f6b416
      Martin Schwidefsky authored
      
      
      The current virtual timer interface is inherently per-cpu and hard to
      use. The sole user of the interface is appldata which uses it to execute
      a function after a specific amount of cputime has been used over all cpus.
      
      Rework the virtual timer interface to hook into the cputime accounting.
      This makes the interface independent from the CPU timer interrupts, and
      makes the virtual timers global as opposed to per-cpu.
      Overall the code is greatly simplified. The downside is that the accuracy
      is not as good as the original implementation, but it is still good enough
      for appldata.
      Reviewed-by: default avatarJan Glauber <jang@linux.vnet.ibm.com>
      Reviewed-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      27f6b416
    • Heiko Carstens's avatar
      s390/comments: unify copyright messages and remove file names · a53c8fab
      Heiko Carstens authored
      
      
      Remove the file name from the comment at top of many files. In most
      cases the file name was wrong anyway, so it's rather pointless.
      
      Also unify the IBM copyright statement. We did have a lot of sightly
      different statements and wanted to change them one after another
      whenever a file gets touched. However that never happened. Instead
      people start to take the old/"wrong" statements to use as a template
      for new files.
      So unify all of them in one go.
      Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      a53c8fab
  5. 28 Mar, 2012 1 commit
  6. 11 Mar, 2012 1 commit
    • Martin Schwidefsky's avatar
      [S390] rework idle code · 4c1051e3
      Martin Schwidefsky authored
      
      
      Whenever the cpu loads an enabled wait PSW it will appear as idle to the
      underlying host system. The code in default_idle calls vtime_stop_cpu
      which does the necessary voodoo to get the cpu time accounting right.
      The udelay code just loads an enabled wait PSW. To correct this rework
      the vtime_stop_cpu/vtime_start_cpu logic and move the difficult parts
      to entry[64].S, vtime_stop_cpu can now be called from anywhere and
      vtime_start_cpu is gone. The correction of the cpu time during wakeup
      from an enabled wait PSW is done with a critical section in entry[64].S.
      As vtime_start_cpu is gone, s390_idle_check can be removed as well.
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      4c1051e3
  7. 01 Mar, 2012 1 commit
  8. 27 Feb, 2012 1 commit
  9. 17 Feb, 2012 1 commit
  10. 11 Dec, 2011 3 commits
    • Frederic Weisbecker's avatar
      nohz: Remove tick_nohz_idle_enter_norcu() / tick_nohz_idle_exit_norcu() · 1268fbc7
      Frederic Weisbecker authored
      
      
      Those two APIs were provided to optimize the calls of
      tick_nohz_idle_enter() and rcu_idle_enter() into a single
      irq disabled section. This way no interrupt happening in-between would
      needlessly process any RCU job.
      
      Now we are talking about an optimization for which benefits
      have yet to be measured. Let's start simple and completely decouple
      idle rcu and dyntick idle logics to simplify.
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Reviewed-by: default avatarJosh Triplett <josh@joshtriplett.org>
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      1268fbc7
    • Frederic Weisbecker's avatar
      nohz: Allow rcu extended quiescent state handling seperately from tick stop · 2bbb6817
      Frederic Weisbecker authored
      
      
      It is assumed that rcu won't be used once we switch to tickless
      mode and until we restart the tick. However this is not always
      true, as in x86-64 where we dereference the idle notifiers after
      the tick is stopped.
      
      To prepare for fixing this, add two new APIs:
      tick_nohz_idle_enter_norcu() and tick_nohz_idle_exit_norcu().
      
      If no use of RCU is made in the idle loop between
      tick_nohz_enter_idle() and tick_nohz_exit_idle() calls, the arch
      must instead call the new *_norcu() version such that the arch doesn't
      need to call rcu_idle_enter() and rcu_idle_exit().
      
      Otherwise the arch must call tick_nohz_enter_idle() and
      tick_nohz_exit_idle() and also call explicitly:
      
      - rcu_idle_enter() after its last use of RCU before the CPU is put
      to sleep.
      - rcu_idle_exit() before the first use of RCU after the CPU is woken
      up.
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Mike Frysinger <vapier@gentoo.org>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: David Miller <davem@davemloft.net>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      2bbb6817
    • Frederic Weisbecker's avatar
      nohz: Separate out irq exit and idle loop dyntick logic · 280f0677
      Frederic Weisbecker authored
      
      
      The tick_nohz_stop_sched_tick() function, which tries to delay
      the next timer tick as long as possible, can be called from two
      places:
      
      - From the idle loop to start the dytick idle mode
      - From interrupt exit if we have interrupted the dyntick
      idle mode, so that we reprogram the next tick event in
      case the irq changed some internal state that requires this
      action.
      
      There are only few minor differences between both that
      are handled by that function, driven by the ts->inidle
      cpu variable and the inidle parameter. The whole guarantees
      that we only update the dyntick mode on irq exit if we actually
      interrupted the dyntick idle mode, and that we enter in RCU extended
      quiescent state from idle loop entry only.
      
      Split this function into:
      
      - tick_nohz_idle_enter(), which sets ts->inidle to 1, enters
      dynticks idle mode unconditionally if it can, and enters into RCU
      extended quiescent state.
      
      - tick_nohz_irq_exit() which only updates the dynticks idle mode
      when ts->inidle is set (ie: if tick_nohz_idle_enter() has been called).
      
      To maintain symmetry, tick_nohz_restart_sched_tick() has been renamed
      into tick_nohz_idle_exit().
      
      This simplifies the code and micro-optimize the irq exit path (no need
      for local_irq_save there). This also prepares for the split between
      dynticks and rcu extended quiescent state logics. We'll need this split to
      further fix illegal uses of RCU in extended quiescent states in the idle
      loop.
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Mike Frysinger <vapier@gentoo.org>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: David Miller <davem@davemloft.net>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Reviewed-by: default avatarJosh Triplett <josh@joshtriplett.org>
      280f0677
  11. 30 Oct, 2011 2 commits
  12. 23 May, 2011 1 commit
  13. 12 Jan, 2011 3 commits
  14. 05 Jan, 2011 3 commits
  15. 25 Oct, 2010 1 commit
  16. 17 Aug, 2010 1 commit
    • David Howells's avatar
      Make do_execve() take a const filename pointer · d7627467
      David Howells authored
      
      
      Make do_execve() take a const filename pointer so that kernel_execve() compiles
      correctly on ARM:
      
      arch/arm/kernel/sys_arm.c:88: warning: passing argument 1 of 'do_execve' discards qualifiers from pointer target type
      
      This also requires the argv and envp arguments to be consted twice, once for
      the pointer array and once for the strings the array points to.  This is
      because do_execve() passes a pointer to the filename (now const) to
      copy_strings_kernel().  A simpler alternative would be to cast the filename
      pointer in do_execve() when it's passed to copy_strings_kernel().
      
      do_execve() may not change any of the strings it is passed as part of the argv
      or envp lists as they are some of them in .rodata, so marking these strings as
      const should be fine.
      
      Further kernel_execve() and sys_execve() need to be changed to match.
      
      This has been test built on x86_64, frv, arm and mips.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Tested-by: default avatarRalf Baechle <ralf@linux-mips.org>
      Acked-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d7627467
  17. 13 Aug, 2010 1 commit
  18. 30 Mar, 2010 1 commit
    • Tejun Heo's avatar
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo authored
      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: default avatarTejun Heo <tj@kernel.org>
      Guess-its-ok-by: default avatarChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  19. 13 Jan, 2010 2 commits
  20. 23 Sep, 2009 1 commit
  21. 22 Sep, 2009 2 commits
  22. 18 Jun, 2009 1 commit
  23. 12 Jun, 2009 1 commit
  24. 02 Apr, 2009 1 commit
  25. 26 Mar, 2009 3 commits