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  1. 29 7月, 2008 6 次提交
    • I
      Merge branch 'linus' into cpus4096 · 9e3ee1c3
      由 Ingo Molnar 提交于 
      Conflicts:

	kernel/stop_machine.c
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      9e3ee1c3
    • L
      cpu masks: optimize and clean up cpumask_of_cpu() · e56b3bc7
      由 Linus Torvalds 提交于 
      Clean up and optimize cpumask_of_cpu(), by sharing all the zero words.

Instead of stupidly generating all possible i=0...NR_CPUS 2^i patterns
creating a huge array of constant bitmasks, realize that the zero words
can be shared.

In other words, on a 64-bit architecture, we only ever need 64 of these
arrays - with a different bit set in one single world (with enough zero
words around it so that we can create any bitmask by just offsetting in
that big array). And then we just put enough zeroes around it that we
can point every single cpumask to be one of those things.

So when we have 4k CPU's, instead of having 4k arrays (of 4k bits each,
with one bit set in each array - 2MB memory total), we have exactly 64
arrays instead, each 8k bits in size (64kB total).

And then we just point cpumask(n) to the right position (which we can
calculate dynamically). Once we have the right arrays, getting
"cpumask(n)" ends up being:

  static inline const cpumask_t *get_cpu_mask(unsigned int cpu)
  {
          const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG];
          p -= cpu / BITS_PER_LONG;
          return (const cpumask_t *)p;
  }

This brings other advantages and simplifications as well:

 - we are not wasting memory that is just filled with a single bit in
   various different places

 - we don't need all those games to re-create the arrays in some dense
   format, because they're already going to be dense enough.

if we compile a kernel for up to 4k CPU's, "wasting" that 64kB of memory
is a non-issue (especially since by doing this "overlapping" trick we
probably get better cache behaviour anyway).

[ mingo@elte.hu:

  Converted Linus's mails into a commit. See:

     http://lkml.org/lkml/2008/7/27/156
     http://lkml.org/lkml/2008/7/28/320

  Also applied a family filter - which also has the side-effect of leaving
  out the bits where Linus calls me an idio... Oh, never mind ;-)
]
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Mike Travis <travis@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      e56b3bc7
    • I
      Merge branch 'linus' into cpus4096 · 414f746d
      由 Ingo Molnar 提交于
      414f746d
    • L
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input · f934fb19
      由 Linus Torvalds 提交于 
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: add driver for Atmel integrated touchscreen controller
  Input: ads7846 - optimize order of calculating Rt in ads7846_rx()
  Input: ads7846 - fix sparse endian warnings
  Input: uinput - remove duplicate include
  Input: serio - offload resume to kseriod
  Input: serio - mark serio_register_driver() __must_check
      f934fb19
    • L
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm · 3988ba07
      由 Linus Torvalds 提交于 
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm:
  dlm: fix uninitialized variable for search_rsb_list callers
  dlm: release socket on error
  dlm: fix basts for granted CW waiting PR/CW
  dlm: check for null in device_write
      3988ba07
    • L
      Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc · d9089c29
      由 Linus Torvalds 提交于 
      * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (25 commits)
  powerpc: Disable 64K hugetlb support when doing 64K SPU mappings
  powerpc/powermac: Fixup default serial port device for pmac_zilog
  powerpc/powermac: Use sane default baudrate for SCC debugging
  powerpc/mm: Implement _PAGE_SPECIAL & pte_special() for 64-bit
  powerpc: Show processor cache information in sysfs
  powerpc: Make core id information available to userspace
  powerpc: Make core sibling information available to userspace
  powerpc/vio: More fallout from dma_mapping_error API change
  ibmveth: Fix multiple errors with dma_mapping_error conversion
  powerpc/pseries: Fix CMO sysdev attribute API change fallout
  powerpc: Enable tracehook for the architecture
  powerpc: Add TIF_NOTIFY_RESUME support for tracehook
  powerpc: Add asm/syscall.h with the tracehook entry points
  powerpc: Make syscall tracing use tracehook.h helpers
  powerpc: Call tracehook_signal_handler() when setting up signal frames
  powerpc: Update cpu_sibling_maps dynamically
  powerpc: register_cpu_online should be __cpuinit
  powerpc: kill useless SMT code in prom_hold_cpus
  powerpc: Fix 8xx build failure
  powerpc: Fix vio build warnings
  ...
      d9089c29
  3. 28 7月, 2008 34 次提交