1. 12 Jan, 2006 2 commits
  2. 10 Jan, 2006 1 commit
  3. 08 Jan, 2006 1 commit
  4. 09 Nov, 2005 2 commits
    • Nick Piggin's avatar
      [PATCH] sched: resched and cpu_idle rework · 64c7c8f8
      Nick Piggin authored
      
      
      Make some changes to the NEED_RESCHED and POLLING_NRFLAG to reduce
      confusion, and make their semantics rigid.  Improves efficiency of
      resched_task and some cpu_idle routines.
      
      * In resched_task:
      - TIF_NEED_RESCHED is only cleared with the task's runqueue lock held,
        and as we hold it during resched_task, then there is no need for an
        atomic test and set there. The only other time this should be set is
        when the task's quantum expires, in the timer interrupt - this is
        protected against because the rq lock is irq-safe.
      
      - If TIF_NEED_RESCHED is set, then we don't need to do anything. It
        won't get unset until the task get's schedule()d off.
      
      - If we are running on the same CPU as the task we resched, then set
        TIF_NEED_RESCHED and no further action is required.
      
      - If we are running on another CPU, and TIF_POLLING_NRFLAG is *not* set
        after TIF_NEED_RESCHED has been set, then we need to send an IPI.
      
      Using these rules, we are able to remove the test and set operation in
      resched_task, and make clear the previously vague semantics of
      POLLING_NRFLAG.
      
      * In idle routines:
      - Enter cpu_idle with preempt disabled. When the need_resched() condition
        becomes true, explicitly call schedule(). This makes things a bit clearer
        (IMO), but haven't updated all architectures yet.
      
      - Many do a test and clear of TIF_NEED_RESCHED for some reason. According
        to the resched_task rules, this isn't needed (and actually breaks the
        assumption that TIF_NEED_RESCHED is only cleared with the runqueue lock
        held). So remove that. Generally one less locked memory op when switching
        to the idle thread.
      
      - Many idle routines clear TIF_POLLING_NRFLAG, and only set it in the inner
        most polling idle loops. The above resched_task semantics allow it to be
        set until before the last time need_resched() is checked before going into
        a halt requiring interrupt wakeup.
      
        Many idle routines simply never enter such a halt, and so POLLING_NRFLAG
        can be always left set, completely eliminating resched IPIs when rescheduling
        the idle task.
      
        POLLING_NRFLAG width can be increased, to reduce the chance of resched IPIs.
      Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Con Kolivas <kernel@kolivas.org>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      64c7c8f8
    • Nick Piggin's avatar
      [PATCH] sched: disable preempt in idle tasks · 5bfb5d69
      Nick Piggin authored
      
      
      Run idle threads with preempt disabled.
      
      Also corrected a bugs in arm26's cpu_idle (make it actually call schedule()).
      How did it ever work before?
      
      Might fix the CPU hotplugging hang which Nigel Cunningham noted.
      
      We think the bug hits if the idle thread is preempted after checking
      need_resched() and before going to sleep, then the CPU offlined.
      
      After calling stop_machine_run, the CPU eventually returns from preemption and
      into the idle thread and goes to sleep.  The CPU will continue executing
      previous idle and have no chance to call play_dead.
      
      By disabling preemption until we are ready to explicitly schedule, this bug is
      fixed and the idle threads generally become more robust.
      
      From: alexs <ashepard@u.washington.edu>
      
        PPC build fix
      
      From: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
      
        MIPS build fix
      Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
      Signed-off-by: default avatarYoichi Yuasa <yuasa@hh.iij4u.or.jp>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      5bfb5d69
  5. 07 Nov, 2005 5 commits
  6. 30 Oct, 2005 3 commits
  7. 29 Oct, 2005 4 commits
    • Hugh Dickins's avatar
      [PATCH] mm: i386 sh sh64 ready for split ptlock · 60ec5585
      Hugh Dickins authored
      
      
      Use pte_offset_map_lock, instead of pte_offset_map (or inappropriate
      pte_offset_kernel) and mm-wide page_table_lock, in sundry arch places.
      
      The i386 vm86 mark_screen_rdonly: yes, there was and is an assumption that the
      screen fits inside the one page table, as indeed it does.
      
      The sh __do_page_fault: which handles both kernel faults (without lock) and
      user mm faults (locked - though it set_pte without locking before).
      
      The sh64 flush_cache_range and helpers: which wrongly thought callers held
      page_table_lock before (only its tlb_start_vma did, and no longer does so);
      moved the flush loop down, and adjusted the large versus small range decision
      to consider a range which spans page tables as large.
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Acked-by: default avatarPaul Mundt <lethal@linux-sh.org>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      60ec5585
    • Hugh Dickins's avatar
      [PATCH] mm: init_mm without ptlock · 872fec16
      Hugh Dickins authored
      
      
      First step in pushing down the page_table_lock.  init_mm.page_table_lock has
      been used throughout the architectures (usually for ioremap): not to serialize
      kernel address space allocation (that's usually vmlist_lock), but because
      pud_alloc,pmd_alloc,pte_alloc_kernel expect caller holds it.
      
      Reverse that: don't lock or unlock init_mm.page_table_lock in any of the
      architectures; instead rely on pud_alloc,pmd_alloc,pte_alloc_kernel to take
      and drop it when allocating a new one, to check lest a racing task already
      did.  Similarly no page_table_lock in vmalloc's map_vm_area.
      
      Some temporary ugliness in __pud_alloc and __pmd_alloc: since they also handle
      user mms, which are converted only by a later patch, for now they have to lock
      differently according to whether or not it's init_mm.
      
      If sources get muddled, there's a danger that an arch source taking
      init_mm.page_table_lock will be mixed with common source also taking it (or
      neither take it).  So break the rules and make another change, which should
      break the build for such a mismatch: remove the redundant mm arg from
      pte_alloc_kernel (ppc64 scrapped its distinct ioremap_mm in 2.6.13).
      
      Exceptions: arm26 used pte_alloc_kernel on user mm, now pte_alloc_map; ia64
      used pte_alloc_map on init_mm, now pte_alloc_kernel; parisc had bad args to
      pmd_alloc and pte_alloc_kernel in unused USE_HPPA_IOREMAP code; ppc64
      map_io_page forgot to unlock on failure; ppc mmu_mapin_ram and ppc64 im_free
      took page_table_lock for no good reason.
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      872fec16
    • Hugh Dickins's avatar
      [PATCH] mm: sh64 hugetlbpage.c · 147efea8
      Hugh Dickins authored
      
      
      The sh64 hugetlbpage.c seems to be erroneous, left over from a bygone age,
      clashing with the common hugetlb.c.  Replace it by a copy of the sh
      hugetlbpage.c.  Except, delete that mk_pte_huge macro neither uses.
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Acked-by: default avatarPaul Mundt <lethal@linux-sh.org>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      147efea8
    • Russell King's avatar
      Create platform_device.h to contain all the platform device details. · d052d1be
      Russell King authored
      
      Convert everyone who uses platform_bus_type to include
      linux/platform_device.h.
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      Acked-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      d052d1be
  8. 28 Oct, 2005 1 commit
  9. 13 Oct, 2005 1 commit
  10. 11 Sep, 2005 1 commit
    • Sam Ravnborg's avatar
      kbuild: rename prepare to archprepare to fix dependency chain · 5bb78269
      Sam Ravnborg authored
      
      
      When introducing the generic asm-offsets.h support the dependency
      chain for the prepare targets was changed. All build scripts expecting
      include/asm/asm-offsets.h to be made when using the prepare target would broke.
      With the limited number of prepare targets left in arch Makefiles
      the trivial solution was to introduce a new arch specific target: archprepare
      
      The dependency chain looks like this now:
      
      prepare
        |
        +--> prepare0
               |
               +--> archprepare
                      |
      		+--> scripts_basic
                      +--> prepare1
                             |
                             +---> prepare2
                                     |
                                     +--> prepare3
      
      So prepare 3 is processed before prepare2 etc.
      This guaantees that the asm symlink, version.h, scripts_basic
      are all updated before archprepare is processed.
      
      prepare0 which build the asm-offsets.h file will need the
      actions performed by archprepare.
      
      The head target is now named prepare, because users scripts will most
      likely use that target, but prepare-all has been kept for compatibility.
      Updated Documentation/kbuild/makefiles.txt.
      Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
      5bb78269
  11. 10 Sep, 2005 3 commits
  12. 09 Sep, 2005 1 commit
  13. 07 Sep, 2005 3 commits
  14. 29 Aug, 2005 1 commit
    • Steven Rostedt's avatar
      [PATCH] convert signal handling of NODEFER to act like other Unix boxes. · 69be8f18
      Steven Rostedt authored
      
      
      It has been reported that the way Linux handles NODEFER for signals is
      not consistent with the way other Unix boxes handle it.  I've written a
      program to test the behavior of how this flag affects signals and had
      several reports from people who ran this on various Unix boxes,
      confirming that Linux seems to be unique on the way this is handled.
      
      The way NODEFER affects signals on other Unix boxes is as follows:
      
      1) If NODEFER is set, other signals in sa_mask are still blocked.
      
      2) If NODEFER is set and the signal is in sa_mask, then the signal is
      still blocked. (Note: this is the behavior of all tested but Linux _and_
      NetBSD 2.0 *).
      
      The way NODEFER affects signals on Linux:
      
      1) If NODEFER is set, other signals are _not_ blocked regardless of
      sa_mask (Even NetBSD doesn't do this).
      
      2) If NODEFER is set and the signal is in sa_mask, then the signal being
      handled is not blocked.
      
      The patch converts signal handling in all current Linux architectures to
      the way most Unix boxes work.
      
      Unix boxes that were tested:  DU4, AIX 5.2, Irix 6.5, NetBSD 2.0, SFU
      3.5 on WinXP, AIX 5.3, Mac OSX, and of course Linux 2.6.13-rcX.
      
      * NetBSD was the only other Unix to behave like Linux on point #2. The
      main concern was brought up by point #1 which even NetBSD isn't like
      Linux.  So with this patch, we leave NetBSD as the lonely one that
      behaves differently here with #2.
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      69be8f18
  15. 18 Aug, 2005 1 commit
  16. 27 Jul, 2005 1 commit
  17. 26 Jul, 2005 1 commit
  18. 11 Jul, 2005 1 commit
    • Sam Ravnborg's avatar
      [NET]: add a top-level Networking menu to *config · d5950b43
      Sam Ravnborg authored
      
      
      Create a new top-level menu named "Networking" thus moving
      net related options and protocol selection way from the drivers
      menu and up on the top-level where they belong.
      
      To implement this all architectures has to source "net/Kconfig" before
      drivers/*/Kconfig in their Kconfig file. This change has been
      implemented for all architectures.
      
      Device drivers for ordinary NIC's are still to be found
      in the Device Drivers section, but Bluetooth, IrDA and ax25
      are located with their corresponding menu entries under the new
      networking menu item.
      Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      d5950b43
  19. 23 Jun, 2005 2 commits
  20. 21 Jun, 2005 3 commits
    • Wolfgang Wander's avatar
      [PATCH] Avoiding mmap fragmentation · 1363c3cd
      Wolfgang Wander authored
      
      
      Ingo recently introduced a great speedup for allocating new mmaps using the
      free_area_cache pointer which boosts the specweb SSL benchmark by 4-5% and
      causes huge performance increases in thread creation.
      
      The downside of this patch is that it does lead to fragmentation in the
      mmap-ed areas (visible via /proc/self/maps), such that some applications
      that work fine under 2.4 kernels quickly run out of memory on any 2.6
      kernel.
      
      The problem is twofold:
      
        1) the free_area_cache is used to continue a search for memory where
           the last search ended.  Before the change new areas were always
           searched from the base address on.
      
           So now new small areas are cluttering holes of all sizes
           throughout the whole mmap-able region whereas before small holes
           tended to close holes near the base leaving holes far from the base
           large and available for larger requests.
      
        2) the free_area_cache also is set to the location of the last
           munmap-ed area so in scenarios where we allocate e.g.  five regions of
           1K each, then free regions 4 2 3 in this order the next request for 1K
           will be placed in the position of the old region 3, whereas before we
           appended it to the still active region 1, placing it at the location
           of the old region 2.  Before we had 1 free region of 2K, now we only
           get two free regions of 1K -> fragmentation.
      
      The patch addresses thes issues by introducing yet another cache descriptor
      cached_hole_size that contains the largest known hole size below the
      current free_area_cache.  If a new request comes in the size is compared
      against the cached_hole_size and if the request can be filled with a hole
      below free_area_cache the search is started from the base instead.
      
      The results look promising: Whereas 2.6.12-rc4 fragments quickly and my
      (earlier posted) leakme.c test program terminates after 50000+ iterations
      with 96 distinct and fragmented maps in /proc/self/maps it performs nicely
      (as expected) with thread creation, Ingo's test_str02 with 20000 threads
      requires 0.7s system time.
      
      Taking out Ingo's patch (un-patch available per request) by basically
      deleting all mentions of free_area_cache from the kernel and starting the
      search for new memory always at the respective bases we observe: leakme
      terminates successfully with 11 distinctive hardly fragmented areas in
      /proc/self/maps but thread creating is gringdingly slow: 30+s(!) system
      time for Ingo's test_str02 with 20000 threads.
      
      Now - drumroll ;-) the appended patch works fine with leakme: it ends with
      only 7 distinct areas in /proc/self/maps and also thread creation seems
      sufficiently fast with 0.71s for 20000 threads.
      Signed-off-by: default avatarWolfgang Wander <wwc@rentec.com>
      Credit-to: "Richard Purdie" <rpurdie@rpsys.net>
      Signed-off-by: default avatarKen Chen <kenneth.w.chen@intel.com>
      Acked-by: Ingo Molnar <mingo@elte.hu> (partly)
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      1363c3cd
    • David Gibson's avatar
      [PATCH] Hugepage consolidation · 63551ae0
      David Gibson authored
      
      
      A lot of the code in arch/*/mm/hugetlbpage.c is quite similar.  This patch
      attempts to consolidate a lot of the code across the arch's, putting the
      combined version in mm/hugetlb.c.  There are a couple of uglyish hacks in
      order to covert all the hugepage archs, but the result is a very large
      reduction in the total amount of code.  It also means things like hugepage
      lazy allocation could be implemented in one place, instead of six.
      
      Tested, at least a little, on ppc64, i386 and x86_64.
      
      Notes:
      	- this patch changes the meaning of set_huge_pte() to be more
      	  analagous to set_pte()
      	- does SH4 need s special huge_ptep_get_and_clear()??
      Acked-by: default avatarWilliam Lee Irwin <wli@holomorphy.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      63551ae0
    • Ingo Molnar's avatar
      [PATCH] smp_processor_id() cleanup · 39c715b7
      Ingo Molnar authored
      
      
      This patch implements a number of smp_processor_id() cleanup ideas that
      Arjan van de Ven and I came up with.
      
      The previous __smp_processor_id/_smp_processor_id/smp_processor_id API
      spaghetti was hard to follow both on the implementational and on the
      usage side.
      
      Some of the complexity arose from picking wrong names, some of the
      complexity comes from the fact that not all architectures defined
      __smp_processor_id.
      
      In the new code, there are two externally visible symbols:
      
       - smp_processor_id(): debug variant.
      
       - raw_smp_processor_id(): nondebug variant. Replaces all existing
         uses of _smp_processor_id() and __smp_processor_id(). Defined
         by every SMP architecture in include/asm-*/smp.h.
      
      There is one new internal symbol, dependent on DEBUG_PREEMPT:
      
       - debug_smp_processor_id(): internal debug variant, mapped to
                                   smp_processor_id().
      
      Also, i moved debug_smp_processor_id() from lib/kernel_lock.c into a new
      lib/smp_processor_id.c file.  All related comments got updated and/or
      clarified.
      
      I have build/boot tested the following 8 .config combinations on x86:
      
       {SMP,UP} x {PREEMPT,!PREEMPT} x {DEBUG_PREEMPT,!DEBUG_PREEMPT}
      
      I have also build/boot tested x64 on UP/PREEMPT/DEBUG_PREEMPT.  (Other
      architectures are untested, but should work just fine.)
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarArjan van de Ven <arjan@infradead.org>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      39c715b7
  21. 04 May, 2005 1 commit
    • Al Viro's avatar
      [PATCH] ISA DMA Kconfig fixes - part 1 · 5cae841b
      Al Viro authored
      
      
      A bunch of drivers use ISA DMA helpers or their equivalents for
      platforms that have ISA with different DMA controller (a lot of ARM
      boxen).  Currently there is no way to put such dependency in Kconfig -
      CONFIG_ISA is not it (e.g.  it is not set on platforms that have no ISA
      slots, but have on-board devices that pretend to be ISA ones).
      
      New symbol added - ISA_DMA_API.  Set when we have functional
      enable_dma()/set_dma_mode()/etc.  set of helpers.  Next patches in the
      series will add missing dependencies for drivers that need them.
      
      I'm very carefully staying the hell out of the recurring flamefest on
      what exactly CONFIG_ISA would mean in ideal world - added symbol has a
      well-defined meaning and for now I really want to treat it as completely
      independent from the mess around CONFIG_ISA.
      Signed-off-by: default avatarAl Viro <viro@parcelfarce.linux.theplanet.co.uk>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      5cae841b
  22. 01 May, 2005 1 commit