1. 31 10月, 2005 29 次提交
  2. 30 10月, 2005 11 次提交
    • J
      [libata] change ata_qc_complete() to take error mask as second arg · a7dac447
      Jeff Garzik 提交于
      The second argument to ata_qc_complete() was being used for two
      purposes: communicate the ATA Status register to the completion
      function, and indicate an error.  On legacy PCI IDE hardware, the latter
      is often implicit in the former.  On more modern hardware, the driver
      often completely emulated a Status register value, passing ATA_ERR as an
      indication that something went wrong.
      
      Now that previous code changes have eliminated the need to use drv_stat
      arg to communicate the ATA Status register value, we can convert it to a
      mask of possible error classes.
      
      This will lead to more flexible error handling in the future.
      a7dac447
    • D
      [PATCH] memory hotplug: sysfs and add/remove functions · 3947be19
      Dave Hansen 提交于
      This adds generic memory add/remove and supporting functions for memory
      hotplug into a new file as well as a memory hotplug kernel config option.
      
      Individual architecture patches will follow.
      
      For now, disable memory hotplug when swsusp is enabled.  There's a lot of
      churn there right now.  We'll fix it up properly once it calms down.
      Signed-off-by: NMatt Tolentino <matthew.e.tolentino@intel.com>
      Signed-off-by: NDave Hansen <haveblue@us.ibm.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      3947be19
    • D
      [PATCH] memory hotplug locking: zone span seqlock · bdc8cb98
      Dave Hansen 提交于
      See the "fixup bad_range()" patch for more information, but this actually
      creates a the lock to protect things making assumptions about a zone's size
      staying constant at runtime.
      Signed-off-by: NDave Hansen <haveblue@us.ibm.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      bdc8cb98
    • D
      [PATCH] memory hotplug locking: node_size_lock · 208d54e5
      Dave Hansen 提交于
      pgdat->node_size_lock is basically only neeeded in one place in the normal
      code: show_mem(), which is the arch-specific sysrq-m printing function.
      
      Strictly speaking, the architectures not doing memory hotplug do no need this
      locking in show_mem().  However, they are all included for completeness.  This
      should also make any future consolidation of all of the implementations a
      little more straightforward.
      
      This lock is also held in the sparsemem code during a memory removal, as
      sections are invalidated.  This is the place there pfn_valid() is made false
      for a memory area that's being removed.  The lock is only required when doing
      pfn_valid() operations on memory which the user does not already have a
      reference on the page, such as in show_mem().
      Signed-off-by: NDave Hansen <haveblue@us.ibm.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      208d54e5
    • D
      [PATCH] memory hotplug prep: __section_nr helper · 4ca644d9
      Dave Hansen 提交于
      A little helper that we use in the hotplug code.
      Signed-off-by: NDave Hansen <haveblue@us.ibm.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      4ca644d9
    • H
      [PATCH] mm: update comments to pte lock · b8072f09
      Hugh Dickins 提交于
      Updated several references to page_table_lock in common code comments.
      Signed-off-by: NHugh Dickins <hugh@veritas.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      b8072f09
    • H
      [PATCH] mm: fix rss and mmlist locking · f412ac08
      Hugh Dickins 提交于
      A couple of oddities were guarded by page_table_lock, no longer properly
      guarded when that is split.
      
      The mm_counters of file_rss and anon_rss: make those an atomic_t, or an
      atomic64_t if the architecture supports it, in such a case.  Definitions by
      courtesy of Christoph Lameter: who spent considerable effort on more scalable
      ways of counting, but found insufficient benefit in practice.
      
      And adding an mm with swap to the mmlist for swapoff: the list is well-
      guarded by its own lock, but the list_empty check now has to be repeated
      inside it.
      Signed-off-by: NHugh Dickins <hugh@veritas.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      f412ac08
    • H
      [PATCH] mm: split page table lock · 4c21e2f2
      Hugh Dickins 提交于
      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: NHugh Dickins <hugh@veritas.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      4c21e2f2
    • H
      [PATCH] mm: follow_page with inner ptlock · deceb6cd
      Hugh Dickins 提交于
      Final step in pushing down common core's page_table_lock.  follow_page no
      longer wants caller to hold page_table_lock, uses pte_offset_map_lock itself;
      and so no page_table_lock is taken in get_user_pages itself.
      
      But get_user_pages (and get_futex_key) do then need follow_page to pin the
      page for them: take Daniel's suggestion of bitflags to follow_page.
      
      Need one for WRITE, another for TOUCH (it was the accessed flag before:
      vanished along with check_user_page_readable, but surely get_numa_maps is
      wrong to mark every page it finds as accessed), another for GET.
      
      And another, ANON to dispose of untouched_anonymous_page: it seems silly for
      that to descend a second time, let follow_page observe if there was no page
      table and return ZERO_PAGE if so.  Fix minor bug in that: check VM_LOCKED -
      make_pages_present ought to make readonly anonymous present.
      
      Give get_numa_maps a cond_resched while we're there.
      Signed-off-by: NHugh Dickins <hugh@veritas.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      deceb6cd
    • H
      [PATCH] mm: kill check_user_page_readable · c34d1b4d
      Hugh Dickins 提交于
      check_user_page_readable is a problematic variant of follow_page.  It's used
      only by oprofile's i386 and arm backtrace code, at interrupt time, to
      establish whether a userspace stackframe is currently readable.
      
      This is problematic, because we want to push the page_table_lock down inside
      follow_page, and later split it; whereas oprofile is doing a spin_trylock on
      it (in the i386 case, forgotten in the arm case), and needs that to pin
      perhaps two pages spanned by the stackframe (which might be covered by
      different locks when we split).
      
      I think oprofile is going about this in the wrong way: it doesn't need to know
      the area is readable (neither i386 nor arm uses read protection of user
      pages), it doesn't need to pin the memory, it should simply
      __copy_from_user_inatomic, and see if that succeeds or not.  Sorry, but I've
      not got around to devising the sparse __user annotations for this.
      
      Then we can eliminate check_user_page_readable, and return to a single
      follow_page without the __follow_page variants.
      Signed-off-by: NHugh Dickins <hugh@veritas.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      c34d1b4d
    • H
      [PATCH] mm: rmap with inner ptlock · c0718806
      Hugh Dickins 提交于
      rmap's page_check_address descend without page_table_lock.  First just
      pte_offset_map in case there's no pte present worth locking for, then take
      page_table_lock for the full check, and pass ptl back to caller in the same
      style as pte_offset_map_lock.  __xip_unmap, page_referenced_one and
      try_to_unmap_one use pte_unmap_unlock.  try_to_unmap_cluster also.
      
      page_check_address reformatted to avoid progressive indentation.  No use is
      made of its one error code, return NULL when it fails.
      Signed-off-by: NHugh Dickins <hugh@veritas.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      c0718806