1. 15 3月, 2009 2 次提交
    • J
      x86: add brk allocation for very, very early allocations · 93dbda7c
      Jeremy Fitzhardinge 提交于
      Impact: new interface
      
      Add a brk()-like allocator which effectively extends the bss in order
      to allow very early code to do dynamic allocations.  This is better than
      using statically allocated arrays for data in subsystems which may never
      get used.
      
      The space for brk allocations is in the bss ELF segment, so that the
      space is mapped properly by the code which maps the kernel, and so
      that bootloaders keep the space free rather than putting a ramdisk or
      something into it.
      
      The bss itself, delimited by __bss_stop, ends before the brk area
      (__brk_base to __brk_limit).  The kernel text, data and bss is reserved
      up to __bss_stop.
      
      Any brk-allocated data is reserved separately just before the kernel
      pagetable is built, as that code allocates from unreserved spaces
      in the e820 map, potentially allocating from any unused brk memory.
      Ultimately any unused memory in the brk area is used in the general
      kernel memory pool.
      
      Initially the brk space is set to 1MB, which is probably much larger
      than any user needs (the largest current user is i386 head_32.S's code
      to build the pagetables to map the kernel, which can get fairly large
      with a big kernel image and no PSE support).  So long as the system
      has sufficient memory for the bootloader to reserve the kernel+1MB brk,
      there are no bad effects resulting from an over-large brk.
      Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
      93dbda7c
    • J
      x86: make section delimiter symbols part of their section · b9719a4d
      Jeremy Fitzhardinge 提交于
      Impact: cleanup
      
      Move the symbols delimiting a section part of the section
      (section relative) rather than absolute.  This avoids any
      unexpected gaps between the section-start symbol and the first
      data in the section, which could be caused by implicit
      alignment of the section data.  It also makes the general
      form of vmlinux_64.lds.S consistent with vmlinux_32.lds.S.
      Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
      b9719a4d
  2. 14 3月, 2009 1 次提交
  3. 13 3月, 2009 1 次提交
    • L
      cpuacct: reduce one NULL check in fast-path · 7a46c594
      Li Zefan 提交于
      Impact: micro-optimization
      
      In cpuacct_charge(), task_ca() will never return NULL, so change
      for(...) to do { } while(...) to save one NULL check.
      Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Paul Menage <menage@google.com>
      Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
      Cc: Bharata B Rao <bharata@linux.vnet.ibm.com>
      LKML-Reference: <49B863F5.2060400@cn.fujitsu.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      7a46c594
  4. 12 3月, 2009 11 次提交
  5. 11 3月, 2009 25 次提交