1. 10 Sep, 2005 9 commits
    • Ingo Molnar's avatar
      [PATCH] sched: TASK_NONINTERACTIVE · d79fc0fc
      Ingo Molnar authored
      This patch implements a task state bit (TASK_NONINTERACTIVE), which can be
      used by blocking points to mark the task's wait as "non-interactive".  This
      does not mean the task will be considered a CPU-hog - the wait will simply
      not have an effect on the waiting task's priority - positive or negative
      alike.  Right now only pipe_wait() will make use of it, because it's a
      common source of not-so-interactive waits (kernel compilation jobs, etc.).
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      d79fc0fc
    • Ingo Molnar's avatar
      [PATCH] sched cleanups · 95cdf3b7
      Ingo Molnar authored
      whitespace cleanups.
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      95cdf3b7
    • M.Baris Demiray's avatar
      [PATCH] sched: make idlest_group/cpu cpus_allowed-aware · da5a5522
      M.Baris Demiray authored
      Add relevant checks into find_idlest_group() and find_idlest_cpu() to make
      them return only the groups that have allowed CPUs and allowed CPUs
      respectively.
      Signed-off-by: default avatarM.Baris Demiray <baris@labristeknoloji.com>
      Signed-off-by: default avatarNick Piggin <nickpiggin@yahoo.com.au>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      da5a5522
    • Con Kolivas's avatar
      [PATCH] sched: run SCHED_NORMAL tasks with real time tasks on SMT siblings · fc38ed75
      Con Kolivas authored
      The hyperthread aware nice handling currently puts to sleep any non real
      time task when a real time task is running on its sibling cpu.  This can
      lead to prolonged starvation by having the non real time task pegged to the
      cpu with load balancing not pulling that task away.
      
      Currently we force lower priority hyperthread tasks to run a percentage of
      time difference based on timeslice differences which is meaningless when
      comparing real time tasks to SCHED_NORMAL tasks.  We can allow non real
      time tasks to run with real time tasks on the sibling up to per_cpu_gain%
      if we use jiffies as a counter.
      
      Cleanups and micro-optimisations to the relevant code section should make
      it more understandable as well.
      Signed-off-by: default avatarCon Kolivas <kernel@kolivas.org>
      Acked-by: default avatarIngo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      fc38ed75
    • Paul Fulghum's avatar
      [PATCH] synclink_cs add statistics clear · a7482a2e
      Paul Fulghum authored
      Add ability to clear statistics.
      Signed-off-by: default avatarPaul Fulghum <paulkf@microgate.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      a7482a2e
    • Paul Jackson's avatar
      [PATCH] cpuset semaphore depth check deadlock fix · 4247bdc6
      Paul Jackson authored
      The cpusets-formalize-intermediate-gfp_kernel-containment patch
      has a deadlock problem.
      
      This patch was part of a set of four patches to make more
      extensive use of the cpuset 'mem_exclusive' attribute to
      manage kernel GFP_KERNEL memory allocations and to constrain
      the out-of-memory (oom) killer.
      
      A task that is changing cpusets in particular ways on a system
      when it is very short of free memory could double trip over
      the global cpuset_sem semaphore (get the lock and then deadlock
      trying to get it again).
      
      The second attempt to get cpuset_sem would be in the routine
      cpuset_zone_allowed().  This was discovered by code inspection.
      I can not reproduce the problem except with an artifically
      hacked kernel and a specialized stress test.
      
      In real life you cannot hit this unless you are manipulating
      cpusets, and are very unlikely to hit it unless you are rapidly
      modifying cpusets on a memory tight system.  Even then it would
      be a rare occurence.
      
      If you did hit it, the task double tripping over cpuset_sem
      would deadlock in the kernel, and any other task also trying
      to manipulate cpusets would deadlock there too, on cpuset_sem.
      Your batch manager would be wedged solid (if it was cpuset
      savvy), but classic Unix shells and utilities would work well
      enough to reboot the system.
      
      The unusual condition that led to this bug is that unlike most
      semaphores, cpuset_sem _can_ be acquired while in the page
      allocation code, when __alloc_pages() calls cpuset_zone_allowed.
      So it easy to mistakenly perform the following sequence:
        1) task makes system call to alter a cpuset
        2) take cpuset_sem
        3) try to allocate memory
        4) memory allocator, via cpuset_zone_allowed, trys to take cpuset_sem
        5) deadlock
      
      The reason that this is not a serious bug for most users
      is that almost all calls to allocate memory don't require
      taking cpuset_sem.  Only some code paths off the beaten
      track require taking cpuset_sem -- which is good.  Taking
      a global semaphore on the main code path for allocating
      memory would not scale well.
      
      This patch fixes this deadlock by wrapping the up() and down()
      calls on cpuset_sem in kernel/cpuset.c with code that tracks
      the nesting depth of the current task on that semaphore, and
      only does the real down() if the task doesn't hold the lock
      already, and only does the real up() if the nesting depth
      (number of unmatched downs) is exactly one.
      
      The previous required use of refresh_mems(), anytime that
      the cpuset_sem semaphore was acquired and the code executed
      while holding that semaphore might try to allocate memory, is
      no longer required.  Two refresh_mems() calls were removed
      thanks to this.  This is a good change, as failing to get
      all the necessary refresh_mems() calls placed was a primary
      source of bugs in this cpuset code.  The only remaining call
      to refresh_mems() is made while doing a memory allocation,
      if certain task memory placement data needs to be updated
      from its cpuset, due to the cpuset having been changed behind
      the tasks back.
      Signed-off-by: default avatarPaul Jackson <pj@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      4247bdc6
    • Ingo Molnar's avatar
      [PATCH] spinlock consolidation · fb1c8f93
      Ingo Molnar authored
      This patch (written by me and also containing many suggestions of Arjan van
      de Ven) does a major cleanup of the spinlock code.  It does the following
      things:
      
       - consolidates and enhances the spinlock/rwlock debugging code
      
       - simplifies the asm/spinlock.h files
      
       - encapsulates the raw spinlock type and moves generic spinlock
         features (such as ->break_lock) into the generic code.
      
       - cleans up the spinlock code hierarchy to get rid of the spaghetti.
      
      Most notably there's now only a single variant of the debugging code,
      located in lib/spinlock_debug.c.  (previously we had one SMP debugging
      variant per architecture, plus a separate generic one for UP builds)
      
      Also, i've enhanced the rwlock debugging facility, it will now track
      write-owners.  There is new spinlock-owner/CPU-tracking on SMP builds too.
      All locks have lockup detection now, which will work for both soft and hard
      spin/rwlock lockups.
      
      The arch-level include files now only contain the minimally necessary
      subset of the spinlock code - all the rest that can be generalized now
      lives in the generic headers:
      
       include/asm-i386/spinlock_types.h       |   16
       include/asm-x86_64/spinlock_types.h     |   16
      
      I have also split up the various spinlock variants into separate files,
      making it easier to see which does what. The new layout is:
      
         SMP                         |  UP
         ----------------------------|-----------------------------------
         asm/spinlock_types_smp.h    |  linux/spinlock_types_up.h
         linux/spinlock_types.h      |  linux/spinlock_types.h
         asm/spinlock_smp.h          |  linux/spinlock_up.h
         linux/spinlock_api_smp.h    |  linux/spinlock_api_up.h
         linux/spinlock.h            |  linux/spinlock.h
      
      /*
       * here's the role of the various spinlock/rwlock related include files:
       *
       * on SMP builds:
       *
       *  asm/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the
       *                        initializers
       *
       *  linux/spinlock_types.h:
       *                        defines the generic type and initializers
       *
       *  asm/spinlock.h:       contains the __raw_spin_*()/etc. lowlevel
       *                        implementations, mostly inline assembly code
       *
       *   (also included on UP-debug builds:)
       *
       *  linux/spinlock_api_smp.h:
       *                        contains the prototypes for the _spin_*() APIs.
       *
       *  linux/spinlock.h:     builds the final spin_*() APIs.
       *
       * on UP builds:
       *
       *  linux/spinlock_type_up.h:
       *                        contains the generic, simplified UP spinlock type.
       *                        (which is an empty structure on non-debug builds)
       *
       *  linux/spinlock_types.h:
       *                        defines the generic type and initializers
       *
       *  linux/spinlock_up.h:
       *                        contains the __raw_spin_*()/etc. version of UP
       *                        builds. (which are NOPs on non-debug, non-preempt
       *                        builds)
       *
       *   (included on UP-non-debug builds:)
       *
       *  linux/spinlock_api_up.h:
       *                        builds the _spin_*() APIs.
       *
       *  linux/spinlock.h:     builds the final spin_*() APIs.
       */
      
      All SMP and UP architectures are converted by this patch.
      
      arm, i386, ia64, ppc, ppc64, s390/s390x, x64 was build-tested via
      crosscompilers.  m32r, mips, sh, sparc, have not been tested yet, but should
      be mostly fine.
      
      From: Grant Grundler <grundler@parisc-linux.org>
      
        Booted and lightly tested on a500-44 (64-bit, SMP kernel, dual CPU).
        Builds 32-bit SMP kernel (not booted or tested).  I did not try to build
        non-SMP kernels.  That should be trivial to fix up later if necessary.
      
        I converted bit ops atomic_hash lock to raw_spinlock_t.  Doing so avoids
        some ugly nesting of linux/*.h and asm/*.h files.  Those particular locks
        are well tested and contained entirely inside arch specific code.  I do NOT
        expect any new issues to arise with them.
      
       If someone does ever need to use debug/metrics with them, then they will
        need to unravel this hairball between spinlocks, atomic ops, and bit ops
        that exist only because parisc has exactly one atomic instruction: LDCW
        (load and clear word).
      
      From: "Luck, Tony" <tony.luck@intel.com>
      
         ia64 fix
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarArjan van de Ven <arjanv@infradead.org>
      Signed-off-by: default avatarGrant Grundler <grundler@parisc-linux.org>
      Cc: Matthew Wilcox <willy@debian.org>
      Signed-off-by: default avatarHirokazu Takata <takata@linux-m32r.org>
      Signed-off-by: default avatarMikael Pettersson <mikpe@csd.uu.se>
      Signed-off-by: default avatarBenoit Boissinot <benoit.boissinot@ens-lyon.org>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      fb1c8f93
    • Alan Cox's avatar
      [PATCH] Subject: PATCH: fix numa caused compile warnings · 4327edf6
      Alan Cox authored
      pcibus_to_cpumask expands into more than just an initialiser so gcc
      moans about code before variable declarations.
      Signed-off-by: default avatarAlan Cox <alan@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      4327edf6
    • Andrew Morton's avatar
      [PATCH] ntfs build fix · b4012a98
      Andrew Morton authored
      *** Warning: "bit_spin_lock" [fs/ntfs/ntfs.ko] undefined!
      *** Warning: "bit_spin_unlock" [fs/ntfs/ntfs.ko] undefined!
      
      Cc: Anton Altaparmakov <aia21@cantab.net>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      b4012a98
  2. 09 Sep, 2005 31 commits