1. 10 1月, 2014 1 次提交
    • S
      powerpc/e6500: TLB miss handler with hardware tablewalk support · 28efc35f
      Scott Wood 提交于
      There are a few things that make the existing hw tablewalk handlers
      unsuitable for e6500:
      
       - Indirect entries go in TLB1 (though the resulting direct entries go in
         TLB0).
      
       - It has threads, but no "tlbsrx." -- so we need a spinlock and
         a normal "tlbsx".  Because we need this lock, hardware tablewalk
         is mandatory on e6500 unless we want to add spinlock+tlbsx to
         the normal bolted TLB miss handler.
      
       - TLB1 has no HES (nor next-victim hint) so we need software round robin
         (TODO: integrate this round robin data with hugetlb/KVM)
      
       - The existing tablewalk handlers map half of a page table at a time,
         because IBM hardware has a fixed 1MiB indirect page size.  e6500
         has variable size indirect entries, with a minimum of 2MiB.
         So we can't do the half-page indirect mapping, and even if we
         could it would be less efficient than mapping the full page.
      
       - Like on e5500, the linear mapping is bolted, so we don't need the
         overhead of supporting nested tlb misses.
      
      Note that hardware tablewalk does not work in rev1 of e6500.
      We do not expect to support e6500 rev1 in mainline Linux.
      Signed-off-by: NScott Wood <scottwood@freescale.com>
      Cc: Mihai Caraman <mihai.caraman@freescale.com>
      28efc35f
  2. 03 10月, 2013 1 次提交
    • N
      powerpc: Fix memory hotplug with sparse vmemmap · f7e3334a
      Nathan Fontenot 提交于
      Previous commit 46723bfa... introduced a new config option
      HAVE_BOOTMEM_INFO_NODE that ended up breaking memory hot-remove for ppc
      when sparse vmemmap is not defined.
      
      This patch defines HAVE_BOOTMEM_INFO_NODE for ppc and adds the call to
      register_page_bootmem_info_node. Without this we get a BUG_ON for memory
      hot remove in put_page_bootmem().
      
      This also adds a stub for register_page_bootmem_memmap to allow ppc to build
      with sparse vmemmap defined. Leaving this as a stub is fine since the same
      vmemmap addresses are also handled in vmemmap_populate and as such are
      properly mapped.
      Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
      Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      CC: <stable@vger.kernel.org> [v3.9+]
      f7e3334a
  3. 27 8月, 2013 1 次提交
  4. 04 7月, 2013 5 次提交
    • J
      mm/PPC: prepare for killing free_all_bootmem_node() · 602ddc70
      Jiang Liu 提交于
      Prepare for killing free_all_bootmem_node() by using free_all_bootmem().
      Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Alexander Graf <agraf@suse.de>
      Cc: "Suzuki K. Poulose" <suzuki@in.ibm.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      602ddc70
    • J
      mm/ppc: prepare for removing num_physpages and simplify mem_init() · 369a9d85
      Jiang Liu 提交于
      Prepare for removing num_physpages and simplify mem_init().
      Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      369a9d85
    • J
      mm: concentrate modification of totalram_pages into the mm core · 0c988534
      Jiang Liu 提交于
      Concentrate code to modify totalram_pages into the mm core, so the arch
      memory initialized code doesn't need to take care of it.  With these
      changes applied, only following functions from mm core modify global
      variable totalram_pages: free_bootmem_late(), free_all_bootmem(),
      free_all_bootmem_node(), adjust_managed_page_count().
      
      With this patch applied, it will be much more easier for us to keep
      totalram_pages and zone->managed_pages in consistence.
      Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
      Acked-by: NDavid Howells <dhowells@redhat.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "Michael S. Tsirkin" <mst@redhat.com>
      Cc: <sworddragon2@aol.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Jeremy Fitzhardinge <jeremy@goop.org>
      Cc: Jianguo Wu <wujianguo@huawei.com>
      Cc: Joonsoo Kim <js1304@gmail.com>
      Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Marek Szyprowski <m.szyprowski@samsung.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Michel Lespinasse <walken@google.com>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Tang Chen <tangchen@cn.fujitsu.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Wen Congyang <wency@cn.fujitsu.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0c988534
    • J
      mm: enhance free_reserved_area() to support poisoning memory with zero · dbe67df4
      Jiang Liu 提交于
      Address more review comments from last round of code review.
      1) Enhance free_reserved_area() to support poisoning freed memory with
         pattern '0'. This could be used to get rid of poison_init_mem()
         on ARM64.
      2) A previous patch has disabled memory poison for initmem on s390
         by mistake, so restore to the original behavior.
      3) Remove redundant PAGE_ALIGN() when calling free_reserved_area().
      Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "Michael S. Tsirkin" <mst@redhat.com>
      Cc: <sworddragon2@aol.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Jeremy Fitzhardinge <jeremy@goop.org>
      Cc: Jianguo Wu <wujianguo@huawei.com>
      Cc: Joonsoo Kim <js1304@gmail.com>
      Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Marek Szyprowski <m.szyprowski@samsung.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Michel Lespinasse <walken@google.com>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Tang Chen <tangchen@cn.fujitsu.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Wen Congyang <wency@cn.fujitsu.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      dbe67df4
    • J
      mm: change signature of free_reserved_area() to fix building warnings · 11199692
      Jiang Liu 提交于
      Change signature of free_reserved_area() according to Russell King's
      suggestion to fix following build warnings:
      
        arch/arm/mm/init.c: In function 'mem_init':
        arch/arm/mm/init.c:603:2: warning: passing argument 1 of 'free_reserved_area' makes integer from pointer without a cast [enabled by default]
          free_reserved_area(__va(PHYS_PFN_OFFSET), swapper_pg_dir, 0, NULL);
          ^
        In file included from include/linux/mman.h:4:0,
                         from arch/arm/mm/init.c:15:
        include/linux/mm.h:1301:22: note: expected 'long unsigned int' but argument is of type 'void *'
         extern unsigned long free_reserved_area(unsigned long start, unsigned long end,
      
         mm/page_alloc.c: In function 'free_reserved_area':
      >> mm/page_alloc.c:5134:3: warning: passing argument 1 of 'virt_to_phys' makes pointer from integer without a cast [enabled by default]
         In file included from arch/mips/include/asm/page.h:49:0,
                          from include/linux/mmzone.h:20,
                          from include/linux/gfp.h:4,
                          from include/linux/mm.h:8,
                          from mm/page_alloc.c:18:
         arch/mips/include/asm/io.h:119:29: note: expected 'const volatile void *' but argument is of type 'long unsigned int'
         mm/page_alloc.c: In function 'free_area_init_nodes':
         mm/page_alloc.c:5030:34: warning: array subscript is below array bounds [-Warray-bounds]
      
      Also address some minor code review comments.
      Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
      Reported-by: NArnd Bergmann <arnd@arndb.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "Michael S. Tsirkin" <mst@redhat.com>
      Cc: <sworddragon2@aol.com>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Jeremy Fitzhardinge <jeremy@goop.org>
      Cc: Jianguo Wu <wujianguo@huawei.com>
      Cc: Joonsoo Kim <js1304@gmail.com>
      Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Marek Szyprowski <m.szyprowski@samsung.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Michel Lespinasse <walken@google.com>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Tang Chen <tangchen@cn.fujitsu.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Wen Congyang <wency@cn.fujitsu.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      11199692
  5. 21 6月, 2013 1 次提交
    • A
      powerpc: Make linux pagetable walk safe with THP enabled · 0ac52dd7
      Aneesh Kumar K.V 提交于
      We need to have irqs disabled to handle all the possible parallel update for
      linux page table without holding locks.
      
      Events that we are intersted in while walking page tables are
      1) Page fault
      2) umap
      3) THP split
      4) THP collapse
      
      A) local_irq_disabled:
      ------------------------
      1) page fault:
      A none to valid transition via page fault is not an issue because we
      would either see a none or valid. If it is none, we would error out
      the page table walk. We may need to use on stack values when checking for
      type of page table elements, because if we do
      
      if (!is_hugepd()) {
          if (!pmd_none() {
             if (pmd_bad() {
      
      We could take that bad condition because the pmd got converted to a hugepd
      after the !is_hugepd check via a hugetlb fault.
      
      The right way would be to check for pmd_none higher up or use on stack value.
      
      2) A valid to none conversion via unmap:
      We can safely walk the upper level table, because we don't remove the the
      page table entries until rcu grace period. So even if we followed a
      wrong pointer we still have the pointer valid till the grace period.
      
      A PTE pointer returned need to be atomically checked for _PAGE_PRESENT and
       _PAGE_BUSY. A valid pointer returned could becoming none later. To prevent
      pte_clear we take _PAGE_BUSY.
      
      3) THP split:
      A valid transparent hugepage is converted to nomal page. Before we split we
      do pmd_splitting_flush, which sets the hugepage PTE to _PAGE_SPLITTING
      So when walking page table we need to check for pmd_trans_splitting and
      handle that. The pte returned should also need to be checked for
      _PAGE_SPLITTING before setting _PAGE_BUSY similar to _PAGE_PRESENT. We save
      the value of PTE on stack and check for the flag in the local pte value.
      If we don't have the value set we can safely operate on the local pte value
      and we atomicaly set _PAGE_BUSY.
      
      4) THP collapse:
      A normal page gets converted to hugepage. In the collapse path, we
      mark the pmd none early (pmdp_clear_flush). With irq disabled, if we
      are aleady walking page table we would see the pmd_none and won't continue.
      If we see a valid PMD, we should still check for _PAGE_PRESENT before
      setting _PAGE_BUSY, to make sure we didn't collapse the PTE to a Huge PTE.
      Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      0ac52dd7
  6. 30 4月, 2013 2 次提交
  7. 18 4月, 2013 1 次提交
  8. 24 2月, 2013 1 次提交
  9. 29 1月, 2013 1 次提交
  10. 13 9月, 2012 1 次提交
  11. 07 9月, 2012 1 次提交
  12. 16 8月, 2012 1 次提交
  13. 20 3月, 2012 1 次提交
  14. 09 12月, 2011 1 次提交
    • T
      powerpc: Use HAVE_MEMBLOCK_NODE_MAP · 1d7cfe18
      Tejun Heo 提交于
      powerpc doesn't access early_node_map[] directly and enabling
      HAVE_MEMBLOCK_NODE_MAP is trivial - replacing add_active_range() calls
      with memblock_set_node() and selecting HAVE_MEMBLOCK_NODE_MAP is
      enough.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Yinghai Lu <yinghai@kernel.org>
      1d7cfe18
  15. 08 12月, 2011 1 次提交
    • S
      powerpc: Punch a hole in /dev/mem for librtas · 8a3e3d31
      sukadev@linux.vnet.ibm.com 提交于
      With CONFIG_STRICT_DEVMEM=y, user space cannot read any part of /dev/mem.
      Since this breaks librtas, punch a hole in /dev/mem to allow access to the
      rmo_buffer that librtas needs.
      
      Anton Blanchard reported the problem and helped with the fix.
      
      A quick test for this patch:
      
             # cat /proc/rtas/rmo_buffer
             000000000f190000 10000
      
             # python -c "print 0x000000000f190000 / 0x10000"
             3865
      
             # dd if=/dev/mem of=/tmp/foo count=1 bs=64k skip=3865
             1+0 records in
             1+0 records out
             65536 bytes (66 kB) copied, 0.000205235 s, 319 MB/s
      
             # dd if=/dev/mem of=/tmp/foo
             dd: reading `/dev/mem': Operation not permitted
             0+0 records in
             0+0 records out
             0 bytes (0 B) copied, 0.00022519 s, 0.0 kB/s
      Signed-off-by: NSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
      Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      8a3e3d31
  16. 07 12月, 2011 1 次提交
  17. 28 11月, 2011 1 次提交
    • S
      powerpc: Implement CONFIG_STRICT_DEVMEM · 1d54cf2b
      sukadev@linux.vnet.ibm.com 提交于
      As described in the help text in the patch, this token restricts general
      access to /dev/mem as a way of increasing the security. Specifically, access
      to exclusive IOMEM and kernel RAM is denied unless CONFIG_STRICT_DEVMEM is
      set to 'n'.
      
      Implement the 'devmem_is_allowed()' interface for Powerpc. It will be
      called from range_is_allowed() when userpsace attempts to access /dev/mem.
      
      This patch is based on an earlier patch from Steve Best and with input from
      Paul Mackerras and Scott Wood.
      
      [BenH] Fixed a typo or two and removed the generic change which should
             be submitted as a separate patch
      Signed-off-by: NSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
      Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      1d54cf2b
  18. 08 11月, 2011 1 次提交
  19. 01 11月, 2011 1 次提交
  20. 20 9月, 2011 2 次提交
    • A
      powerpc: Fix oops when echoing bad values to /sys/devices/system/memory/probe · a1194097
      Anton Blanchard 提交于
      If we echo an address the hypervisor doesn't like to
      /sys/devices/system/memory/probe we oops the box:
      
      # echo 0x10000000000 > /sys/devices/system/memory/probe
      
      kernel BUG at arch/powerpc/mm/hash_utils_64.c:541!
      
      The backtrace is:
      
      create_section_mapping
      arch_add_memory
      add_memory
      memory_probe_store
      sysdev_class_store
      sysfs_write_file
      vfs_write
      SyS_write
      
      In create_section_mapping we BUG if htab_bolt_mapping returned
      an error. A better approach is to return an error which will
      propagate back to userspace.
      
      Rerunning the test with this patch applied:
      
      # echo 0x10000000000 > /sys/devices/system/memory/probe
      -bash: echo: write error: Invalid argument
      Signed-off-by: NAnton Blanchard <anton@samba.org>
      Cc: stable@kernel.org
      Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      a1194097
    • B
      powerpc: Hugetlb for BookE · 41151e77
      Becky Bruce 提交于
      Enable hugepages on Freescale BookE processors.  This allows the kernel to
      use huge TLB entries to map pages, which can greatly reduce the number of
      TLB misses and the amount of TLB thrashing experienced by applications with
      large memory footprints.  Care should be taken when using this on FSL
      processors, as the number of large TLB entries supported by the core is low
      (16-64) on current processors.
      
      The supported set of hugepage sizes include 4m, 16m, 64m, 256m, and 1g.
      Page sizes larger than the max zone size are called "gigantic" pages and
      must be allocated on the command line (and cannot be deallocated).
      
      This is currently only fully implemented for Freescale 32-bit BookE
      processors, but there is some infrastructure in the code for
      64-bit BooKE.
      Signed-off-by: NBecky Bruce <beckyb@kernel.crashing.org>
      Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
      Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      41151e77
  21. 19 7月, 2011 1 次提交
  22. 08 7月, 2011 1 次提交
  23. 30 6月, 2011 2 次提交
  24. 29 6月, 2011 1 次提交
  25. 09 6月, 2011 1 次提交
    • B
      powerpc: Force page alignment for initrd reserved memory · 307cfe71
      Benjamin Herrenschmidt 提交于
      When using 64K pages with a separate cpio rootfs, U-Boot will align
      the rootfs on a 4K page boundary. When the memory is reserved, and
      subsequent early memblock_alloc is called, it will allocate memory
      between the 64K page alignment and reserved memory. When the reserved
      memory is subsequently freed, it is done so by pages, causing the
      early memblock_alloc requests to be re-used, which in my case, caused
      the device-tree to be clobbered.
      
      This patch forces the reserved memory for initrd to be kernel page
      aligned, and will move the device tree if it overlaps with the range
      extension of initrd. This patch will also consolidate the identical
      function free_initrd_mem() from mm/init_32.c, init_64.c to mm/mem.c,
      and adds the same range extension when freeing initrd. free_initrd_mem()
      is also moved to the __init section.
      
      Many thanks to Milton Miller for his input on this patch.
      
      [BenH: Fixed build without CONFIG_BLK_DEV_INITRD]
      Signed-off-by: NDave Carroll <dcarroll@astekcorp.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      307cfe71
  26. 31 3月, 2011 1 次提交
  27. 13 10月, 2010 1 次提交
    • Y
      memblock, bootmem: Round pfn properly for memory and reserved regions · c7fc2de0
      Yinghai Lu 提交于
      We need to round memory regions correctly -- specifically, we need to
      round reserved region in the more expansive direction (lower limit
      down, upper limit up) whereas usable memory regions need to be rounded
      in the more restrictive direction (lower limit up, upper limit down).
      
      This introduces two set of inlines:
      
      	memblock_region_memory_base_pfn()
      	memblock_region_memory_end_pfn()
      	memblock_region_reserved_base_pfn()
      	memblock_region_reserved_end_pfn()
      
      Although they are antisymmetric (and therefore are technically
      duplicates) the use of the different inlines explicitly documents the
      programmer's intention.
      
      The lack of proper rounding caused a bug on ARM, which was then found
      to also affect other architectures.
      Reported-by: NRussell King <rmk@arm.linux.org.uk>
      Signed-off-by: NYinghai Lu <yinghai@kernel.org>
      LKML-Reference: <4CB4CDFD.4020105@kernel.org>
      Cc: Jeremy Fitzhardinge <jeremy@goop.org>
      Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      c7fc2de0
  28. 05 8月, 2010 1 次提交
  29. 04 8月, 2010 2 次提交
  30. 14 7月, 2010 1 次提交
  31. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo 提交于
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  32. 19 3月, 2010 1 次提交