1. 23 Mar, 2006 1 commit
    • Andrew Morton's avatar
      [PATCH] more for_each_cpu() conversions · 394e3902
      Andrew Morton authored
      
      
      When we stop allocating percpu memory for not-possible CPUs we must not touch
      the percpu data for not-possible CPUs at all.  The correct way of doing this
      is to test cpu_possible() or to use for_each_cpu().
      
      This patch is a kernel-wide sweep of all instances of NR_CPUS.  I found very
      few instances of this bug, if any.  But the patch converts lots of open-coded
      test to use the preferred helper macros.
      
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: David Howells <dhowells@redhat.com>
      Acked-by: default avatarKyle McMartin <kyle@parisc-linux.org>
      Cc: Anton Blanchard <anton@samba.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: William Lee Irwin III <wli@holomorphy.com>
      Cc: Andi Kleen <ak@muc.de>
      Cc: Christian Zankel <chris@zankel.net>
      Cc: Philippe Elie <phil.el@wanadoo.fr>
      Cc: Nathan Scott <nathans@sgi.com>
      Cc: Jens Axboe <axboe@suse.de>
      Cc: Eric Dumazet <dada1@cosmosbay.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      394e3902
  2. 22 Mar, 2006 3 commits
  3. 14 Feb, 2006 3 commits
    • David Howells's avatar
      [PATCH] FRV: Use virtual interrupt disablement · 28baebae
      David Howells authored
      
      
      Make the FRV arch use virtual interrupt disablement because accesses to the
      processor status register (PSR) are relatively slow and because we will
      soon have the need to deal with multiple interrupt controls at the same
      time (separate h/w and inter-core interrupts).
      
      The way this is done is to dedicate one of the four integer condition code
      registers (ICC2) to maintaining a virtual interrupt disablement state
      whilst inside the kernel.  This uses the ICC2.Z flag (Zero) to indicate
      whether the interrupts are virtually disabled and the ICC2.C flag (Carry)
      to indicate whether the interrupts are physically disabled.
      
      ICC2.Z is set to indicate interrupts are virtually disabled.  ICC2.C is set
      to indicate interrupts are physically enabled.  Under normal running
      conditions Z==0 and C==1.
      
      Disabling interrupts with local_irq_disable() doesn't then actually
      physically disable interrupts - it merely sets ICC2.Z to 1.  Should an
      interrupt then happen, the exception prologue will note ICC2.Z is set and
      branch out of line using one instruction (an unlikely BEQ).  Here it will
      physically disable interrupts and clear ICC2.C.
      
      When it comes time to enable interrupts (local_irq_enable()), this simply
      clears the ICC2.Z flag and invokes a trap #2 if both Z and C flags are
      clear (the HI integer condition).  This can be done with the TIHI
      conditional trap instruction.
      
      The trap then physically reenables interrupts and sets ICC2.C again.  Upon
      returning the interrupt will be taken as interrupts will then be enabled.
      Note that whilst processing the trap, the whole exceptions system is
      disabled, and so an interrupt can't happen till it returns.
      
      If no pending interrupt had happened, ICC2.C would still be set, the HI
      condition would not be fulfilled, and no trap will happen.
      
      Saving interrupts (local_irq_save) is simply a matter of pulling the ICC2.Z
      flag out of the CCR register, shifting it down and masking it off.  This
      gives a result of 0 if interrupts were enabled and 1 if they weren't.
      
      Restoring interrupts (local_irq_restore) is then a matter of taking the
      saved value mentioned previously and XOR'ing it against 1.  If it was one,
      the result will be zero, and if it was zero the result will be non-zero.
      This result is then used to affect the ICC2.Z flag directly (it is a
      condition code flag after all).  An XOR instruction does not affect the
      Carry flag, and so that bit of state is unchanged.  The two flags can then
      be sampled to see if they're both zero using the trap (TIHI) as for the
      unconditional reenablement (local_irq_enable).
      
      This patch also:
      
       (1) Modifies the debugging stub (break.S) to handle single-stepping crossing
           into the trap #2 handler and into virtually disabled interrupts.
      
       (2) Removes superseded fixup pointers from the second instructions in the trap
           tables (there's no a separate fixup table for this).
      
       (3) Declares the trap #3 vector for use in .org directives in the trap table.
      
       (4) Moves irq_enter() and irq_exit() in do_IRQ() to avoid problems with
           virtual interrupt handling, and removes the duplicate code that has now
           been folded into irq_exit() (softirq and preemption handling).
      
       (5) Tells the compiler in the arch Makefile that ICC2 is now reserved.
      
       (6) Documents the in-kernel ABI, including the virtual interrupts.
      
       (7) Renames the old irq management functions to different names.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      28baebae
    • David Howells's avatar
      [PATCH] FRV: Miscellaneous fixes · 68f624fc
      David Howells authored
      
      
      Make various alterations and fixes to the FRV arch:
      
       (1) Resyncs the FRV system call collection with the i386 arch.
      
       (2) Discards __iounmap() as it's not used.
      
       (3) Fixes the use of the SWAP/SWAPI instruction to get the arguments the right
           way around in atomic.h, and also to get the asm constraints correct.
      
       (4) Moves copy_to/from_user_page() to asm/cacheflush.h to be consistent with
           other archs.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      68f624fc
    • Ingo Molnar's avatar
      [PATCH] hrtimer: round up relative start time on low-res arches · 06027bdd
      Ingo Molnar authored
      
      
      CONFIG_TIME_LOW_RES is a temporary way for architectures to signal that
      they simply return xtime in do_gettimeoffset().  In this corner-case we
      want to round up by resolution when starting a relative timer, to avoid
      short timeouts.  This will go away with the GTOD framework.
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      Cc: Roman Zippel <zippel@linux-m68k.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      06027bdd
  4. 18 Jan, 2006 1 commit
    • David Howells's avatar
      [PATCH] Handle TIF_RESTORE_SIGMASK for FRV · a411aee9
      David Howells authored
      
      
      Handle TIF_RESTORE_SIGMASK as added by David Woodhouse's patch entitled:
      
              [PATCH] 2/3 Add TIF_RESTORE_SIGMASK support for arch/powerpc
              [PATCH] 3/3 Generic sys_rt_sigsuspend
      
      It does the following:
      
       (1) Declares TIF_RESTORE_SIGMASK for FRV.
      
       (2) Invokes it over to do_signal() when TIF_RESTORE_SIGMASK is set.
      
       (3) Makes do_signal() support TIF_RESTORE_SIGMASK, using the signal mask saved
           in current->saved_sigmask.
      
       (4) Discards sys_rt_sigsuspend() from the arch, using the generic one instead.
      
       (5) Makes sys_sigsuspend() save the signal mask and set TIF_RESTORE_SIGMASK
           rather than attempting to fudge the return registers.
      
       (6) Makes sys_sigsuspend() return -ERESTARTNOHAND rather than looping
           intrinsically.
      
       (7) Makes setup_frame(), setup_rt_frame() and handle_signal() return 0 or
           -EFAULT rather than true/false to be consistent with the rest of the
            kernel.
      
      Due to the fact do_signal() is then only called from one place:
      
       (8) Make do_signal() no longer have a return value is it was just being
           ignored; force_sig() takes care of this.
      
       (9) Discards the old sigmask argument to do_signal() as it's no longer
           necessary.
      
      This patch depends on the FRV signalling patches as well as the
      sys_rt_sigsuspend patch.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarDavid Woodhouse <dwmw2@infradead.org>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      a411aee9
  5. 12 Jan, 2006 1 commit
  6. 10 Jan, 2006 2 commits
  7. 09 Jan, 2006 2 commits
  8. 08 Jan, 2006 10 commits
  9. 06 Jan, 2006 3 commits
  10. 28 Nov, 2005 1 commit
    • David Howells's avatar
      [PATCH] FRV: Make the FRV arch work again · 8080f231
      David Howells authored
      
      
      The attached patch implements a bunch of small changes to the FRV arch to
      make it work again.
      
      It deals with the following problems:
      
       (1) SEM_DEBUG should be SEMAPHORE_DEBUG.
      
       (2) The argument list to pcibios_penalize_isa_irq() has changed.
      
       (3) CONFIG_HIGHMEM can't be used directly in #if as it may not be defined.
      
       (4) page->private is no longer directly accessible.
      
       (5) linux/hardirq.h assumes asm/hardirq.h will include linux/irq.h
      
       (6) The IDE MMIO access functions are given pointers, not integers, and so
           get type casting errors.
      
       (7) __pa() is passed an explicit u64 type in drivers/char/mem.c, but that
           can't be cast directly to a pointer on a 32-bit platform.
      
       (8) SEMAPHORE_DEBUG should not be contingent on WAITQUEUE_DEBUG as that no
           longer exists.
      
       (9) PREEMPT_ACTIVE is too low a value.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      8080f231
  11. 13 Nov, 2005 1 commit
  12. 09 Nov, 2005 1 commit
    • 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
  13. 07 Nov, 2005 1 commit
  14. 30 Oct, 2005 2 commits
  15. 29 Oct, 2005 3 commits
    • Hugh Dickins's avatar
      [PATCH] mm: split page table lock · 4c21e2f2
      Hugh Dickins authored
      
      
      Christoph Lameter demonstrated very poor scalability on the SGI 512-way, with
      a many-threaded application which concurrently initializes different parts of
      a large anonymous area.
      
      This patch corrects that, by using a separate spinlock per page table page, to
      guard the page table entries in that page, instead of using the mm's single
      page_table_lock.  (But even then, page_table_lock is still used to guard page
      table allocation, and anon_vma allocation.)
      
      In this implementation, the spinlock is tucked inside the struct page of the
      page table page: with a BUILD_BUG_ON in case it overflows - which it would in
      the case of 32-bit PA-RISC with spinlock debugging enabled.
      
      Splitting the lock is not quite for free: another cacheline access.  Ideally,
      I suppose we would use split ptlock only for multi-threaded processes on
      multi-cpu machines; but deciding that dynamically would have its own costs.
      So for now enable it by config, at some number of cpus - since the Kconfig
      language doesn't support inequalities, let preprocessor compare that with
      NR_CPUS.  But I don't think it's worth being user-configurable: for good
      testing of both split and unsplit configs, split now at 4 cpus, and perhaps
      change that to 8 later.
      
      There is a benefit even for singly threaded processes: kswapd can be attacking
      one part of the mm while another part is busy faulting.
      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>
      4c21e2f2
    • 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
    • Al Viro's avatar
      [PATCH] missing exports of do_settimeofday() variants · 943eae03
      Al Viro authored
      
      
      frv, sh64, ia64 and sparc64 do not have do_settimeofday() exported (the
      last two are using variant in kernel/time.c).  Exports added to match
      the rest of architectures.
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      943eae03
  16. 28 Oct, 2005 1 commit
  17. 09 Sep, 2005 1 commit
  18. 07 Sep, 2005 1 commit
  19. 05 Sep, 2005 1 commit
  20. 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