Eric Lee / smarc-fsl-linux-kernel

09 Jan, 2012

3 commits

12 Dec, 2011

3 commits

  • 1268fbc74   nohz: Remove tick_nohz_idle_enter_norcu() / tick_nohz_idle_exit_norcu() ... Browse Code »

    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: Frederic Weisbecker
    Cc: Ingo Molnar
    Cc: Thomas Gleixner
    Cc: Peter Zijlstra
    Reviewed-by: Josh Triplett
    Signed-off-by: Paul E. McKenney

    Frederic Weisbecker
     
  • 2bbb6817c   nohz: Allow rcu extended quiescent state handling seperately from tick stop ... Browse Code »

    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: Frederic Weisbecker
    Cc: Mike Frysinger
    Cc: Guan Xuetao
    Cc: David Miller
    Cc: Chris Metcalf
    Cc: Hans-Christian Egtvedt
    Cc: Ralf Baechle
    Cc: Paul E. McKenney
    Cc: Ingo Molnar
    Cc: Peter Zijlstra
    Cc: Thomas Gleixner
    Cc: H. Peter Anvin
    Cc: Russell King
    Cc: Paul Mackerras
    Cc: Heiko Carstens
    Cc: Paul Mundt
    Signed-off-by: Paul E. McKenney

    Frederic Weisbecker
     
  • 280f06774   nohz: Separate out irq exit and idle loop dyntick logic ... Browse Code »

    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: Frederic Weisbecker
    Cc: Mike Frysinger
    Cc: Guan Xuetao
    Cc: David Miller
    Cc: Chris Metcalf
    Cc: Hans-Christian Egtvedt
    Cc: Ralf Baechle
    Cc: Paul E. McKenney
    Cc: Ingo Molnar
    Cc: Peter Zijlstra
    Cc: Thomas Gleixner
    Cc: H. Peter Anvin
    Cc: Russell King
    Cc: Paul Mackerras
    Cc: Heiko Carstens
    Cc: Paul Mundt
    Signed-off-by: Paul E. McKenney
    Reviewed-by: Josh Triplett

    Frederic Weisbecker
     

01 Nov, 2011

1 commit

26 Oct, 2011

2 commits

27 Jul, 2011

1 commit

  • 60063497a   atomic: use <linux/atomic.h> ... Browse Code »

    This allows us to move duplicated code in
    (atomic_inc_not_zero() for now) to

    Signed-off-by: Arun Sharma
    Reviewed-by: Eric Dumazet
    Cc: Ingo Molnar
    Cc: David Miller
    Cc: Eric Dumazet
    Acked-by: Mike Frysinger
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Arun Sharma
     

24 Jul, 2011

1 commit

  • 66574cc05   modules: make arch's use default loader hooks ... Browse Code »

    This patch removes all the module loader hook implementations in the
    architecture specific code where the functionality is the same as that
    now provided by the recently added default hooks.

    Signed-off-by: Jonas Bonn
    Acked-by: Mike Frysinger
    Acked-by: Geert Uytterhoeven
    Tested-by: Michal Simek
    Signed-off-by: Rusty Russell

    Jonas Bonn
     

23 Jul, 2011

16 commits

29 May, 2011

2 commits

  • c320afe96   Blackfin: debug-mmrs: include RSI_PID[4567] MMRs ... Browse Code »

    The documentation is a little iffy as to whether these are actual MMRs,
    but reading them on the hardware works, and the previous version of this
    logic (the SDH) had PID[4567]. So add it for RSI too.

    Signed-off-by: Mike Frysinger

    Mike Frysinger
     
  • d09fb6020   Blackfin: debug-mmrs: fix typos with gptimers/mdma/ppi ... Browse Code »

    This code was mostly developed against a BF54x, so some BF537-specific
    issues were missed.

    The PPI block starts at PPI_CONTROL, not PPI_STATUS (which is the reverse
    of the EPPI block).

    The MDMA block starts at MDMA_NEXT_DESC_PTR, not MDMA_CONFIG. Seems the
    sim does not catch misreads here so that'll need to get fixed.

    The gptimer block is mostly 32bit regs, not 16bit. Use the gptimer struct
    to figure that out rather than hardcoding it locally.

    Signed-off-by: Mike Frysinger

    Mike Frysinger
     

25 May, 2011

11 commits