23 Nov, 2011

2 commits

• a855b84c3   percpu: fix chunk range calculation ... Browse Code »

  1

  Percpu allocator recorded the cpus which map to the first and last
  units in pcpu_first/last_unit_cpu respectively and used them to
  determine the address range of a chunk - e.g. it assumed that the
  first unit has the lowest address in a chunk while the last unit has
  the highest address.

  This simply isn't true. Groups in a chunk can have arbitrary positive
  or negative offsets from the previous one and there is no guarantee
  that the first unit occupies the lowest offset while the last one the
  highest.

  Fix it by actually comparing unit offsets to determine cpus occupying
  the lowest and highest offsets. Also, rename pcu_first/last_unit_cpu
  to pcpu_low/high_unit_cpu to avoid confusion.

  The chunk address range is used to flush cache on vmalloc area
  map/unmap and decide whether a given address is in the first chunk by
  per_cpu_ptr_to_phys() and the bug was discovered by invalid
  per_cpu_ptr_to_phys() translation for crash_note.

  Kudos to Dave Young for tracking down the problem.

  Signed-off-by: Tejun Heo
  Reported-by: WANG Cong
  Reported-by: Dave Young
  Tested-by: Dave Young
  LKML-Reference:
  Cc: stable @kernel.org

  Tejun Heo

  2011-11-23 00:09:46 +0800  
• 90459ce06   percpu: rename pcpu_mem_alloc to pcpu_mem_zalloc ... Browse Code »

  Currently pcpu_mem_alloc() is implemented always return zeroed memory.
  So rename it to make user like pcpu_get_pages_and_bitmap() know don't
  reinit it.

  Signed-off-by: Bob Liu
  Reviewed-by: Pekka Enberg
  Reviewed-by: Michal Hocko
  Signed-off-by: Tejun Heo

  Bob Liu

  2011-11-23 00:09:41 +0800  

14 Jan, 2011

1 commit

• ec3f64fc9   mm: remove gfp mask from pcpu_get_vm_areas ... Browse Code »

  pcpu_get_vm_areas() only uses GFP_KERNEL allocations, so remove the gfp_t
  formal and use the mask internally.

  Signed-off-by: David Rientjes
  Cc: Christoph Lameter
  Cc: Tejun Heo
  Signed-off-by: Andrew Morton
  Signed-off-by: Linus Torvalds

  David Rientjes

  2011-01-14 09:32:34 +0800  

01 May, 2010

1 commit

• 9f6455325   percpu: move vmalloc based chunk management into percpu-vm.c ... Browse Code »

  Separate out and move chunk management (creation/desctruction and
  [de]population) code into percpu-vm.c which is included by percpu.c
  and compiled together. The interface for chunk management is defined
  as follows.

  * pcpu_populate_chunk - populate the specified range of a chunk
  * pcpu_depopulate_chunk - depopulate the specified range of a chunk
  * pcpu_create_chunk - create a new chunk
  * pcpu_destroy_chunk - destroy a chunk, always preceded by full depop
  * pcpu_addr_to_page - translate address to physical address
  * pcpu_verify_alloc_info - check alloc_info is acceptable during init

  Other than wrapping vmalloc_to_page() inside pcpu_addr_to_page() and
  dummy pcpu_verify_alloc_info() implementation, this patch only moves
  code around. This separation is to allow alternate chunk management
  implementation.

  Signed-off-by: Tejun Heo
  Reviewed-by: David Howells
  Cc: Graff Yang
  Cc: Sonic Zhang

  Tejun Heo

  2010-05-01 14:30:50 +0800