1. 25 7月, 2008 1 次提交
  2. 05 7月, 2008 1 次提交
  3. 07 6月, 2008 1 次提交
  4. 30 4月, 2008 2 次提交
  5. 03 1月, 2008 1 次提交
  6. 17 10月, 2007 2 次提交
  7. 21 7月, 2007 1 次提交
  8. 20 7月, 2007 1 次提交
    • P
      mm: Remove slab destructors from kmem_cache_create(). · 20c2df83
      Paul Mundt 提交于
      Slab destructors were no longer supported after Christoph's
      c59def9f change. They've been
      BUGs for both slab and slub, and slob never supported them
      either.
      
      This rips out support for the dtor pointer from kmem_cache_create()
      completely and fixes up every single callsite in the kernel (there were
      about 224, not including the slab allocator definitions themselves,
      or the documentation references).
      Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
      20c2df83
  9. 18 7月, 2007 2 次提交
  10. 17 7月, 2007 2 次提交
  11. 24 6月, 2007 1 次提交
  12. 17 5月, 2007 3 次提交
    • C
      Slab allocators: define common size limitations · 0aa817f0
      Christoph Lameter 提交于
      Currently we have a maze of configuration variables that determine the
      maximum slab size.  Worst of all it seems to vary between SLAB and SLUB.
      
      So define a common maximum size for kmalloc.  For conveniences sake we use
      the maximum size ever supported which is 32 MB.  We limit the maximum size
      to a lower limit if MAX_ORDER does not allow such large allocations.
      
      For many architectures this patch will have the effect of adding large
      kmalloc sizes.  x86_64 adds 5 new kmalloc sizes.  So a small amount of
      memory will be needed for these caches (contemporary SLAB has dynamically
      sizeable node and cpu structure so the waste is less than in the past)
      
      Most architectures will then be able to allocate object with sizes up to
      MAX_ORDER.  We have had repeated breakage (in fact whenever we doubled the
      number of supported processors) on IA64 because one or the other struct
      grew beyond what the slab allocators supported.  This will avoid future
      issues and f.e.  avoid fixes for 2k and 4k cpu support.
      
      CONFIG_LARGE_ALLOCS is no longer necessary so drop it.
      
      It fixes sparc64 with SLAB.
      Signed-off-by: NChristoph Lameter <clameter@sgi.com>
      Signed-off-by: N"David S. Miller" <davem@davemloft.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0aa817f0
    • C
      Remove SLAB_CTOR_CONSTRUCTOR · a35afb83
      Christoph Lameter 提交于
      SLAB_CTOR_CONSTRUCTOR is always specified. No point in checking it.
      Signed-off-by: NChristoph Lameter <clameter@sgi.com>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Jens Axboe <jens.axboe@oracle.com>
      Cc: Steven French <sfrench@us.ibm.com>
      Cc: Michael Halcrow <mhalcrow@us.ibm.com>
      Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
      Cc: Miklos Szeredi <miklos@szeredi.hu>
      Cc: Steven Whitehouse <swhiteho@redhat.com>
      Cc: Roman Zippel <zippel@linux-m68k.org>
      Cc: David Woodhouse <dwmw2@infradead.org>
      Cc: Dave Kleikamp <shaggy@austin.ibm.com>
      Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
      Cc: "J. Bruce Fields" <bfields@fieldses.org>
      Cc: Anton Altaparmakov <aia21@cantab.net>
      Cc: Mark Fasheh <mark.fasheh@oracle.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Jan Kara <jack@ucw.cz>
      Cc: David Chinner <dgc@sgi.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a35afb83
    • C
      SLAB: Move two remaining SLAB specific definitions to slab_def.h · 3ca12ee5
      Christoph Lameter 提交于
      Two definitions remained in slab.h that are particular to the SLAB allocator.
      Move to slab_def.h
      Signed-off-by: NChristoph Lameter <clameter@sgi.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      3ca12ee5
  13. 08 5月, 2007 7 次提交
    • C
      slab allocators: Remove SLAB_CTOR_ATOMIC · 4f104934
      Christoph Lameter 提交于
      SLAB_CTOR atomic is never used which is no surprise since I cannot imagine
      that one would want to do something serious in a constructor or destructor.
       In particular given that the slab allocators run with interrupts disabled.
       Actions in constructors and destructors are by their nature very limited
      and usually do not go beyond initializing variables and list operations.
      
      (The i386 pgd ctor and dtors do take a spinlock in constructor and
      destructor.....  I think that is the furthest we go at this point.)
      
      There is no flag passed to the destructor so removing SLAB_CTOR_ATOMIC also
      establishes a certain symmetry.
      Signed-off-by: NChristoph Lameter <clameter@sgi.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      4f104934
    • C
      slab allocators: Remove SLAB_DEBUG_INITIAL flag · 50953fe9
      Christoph Lameter 提交于
      I have never seen a use of SLAB_DEBUG_INITIAL.  It is only supported by
      SLAB.
      
      I think its purpose was to have a callback after an object has been freed
      to verify that the state is the constructor state again?  The callback is
      performed before each freeing of an object.
      
      I would think that it is much easier to check the object state manually
      before the free.  That also places the check near the code object
      manipulation of the object.
      
      Also the SLAB_DEBUG_INITIAL callback is only performed if the kernel was
      compiled with SLAB debugging on.  If there would be code in a constructor
      handling SLAB_DEBUG_INITIAL then it would have to be conditional on
      SLAB_DEBUG otherwise it would just be dead code.  But there is no such code
      in the kernel.  I think SLUB_DEBUG_INITIAL is too problematic to make real
      use of, difficult to understand and there are easier ways to accomplish the
      same effect (i.e.  add debug code before kfree).
      
      There is a related flag SLAB_CTOR_VERIFY that is frequently checked to be
      clear in fs inode caches.  Remove the pointless checks (they would even be
      pointless without removeal of SLAB_DEBUG_INITIAL) from the fs constructors.
      
      This is the last slab flag that SLUB did not support.  Remove the check for
      unimplemented flags from SLUB.
      Signed-off-by: NChristoph Lameter <clameter@sgi.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      50953fe9
    • C
      KMEM_CACHE(): simplify slab cache creation · 0a31bd5f
      Christoph Lameter 提交于
      This patch provides a new macro
      
      KMEM_CACHE(<struct>, <flags>)
      
      to simplify slab creation. KMEM_CACHE creates a slab with the name of the
      struct, with the size of the struct and with the alignment of the struct.
      Additional slab flags may be specified if necessary.
      
      Example
      
      struct test_slab {
      	int a,b,c;
      	struct list_head;
      } __cacheline_aligned_in_smp;
      
      test_slab_cache = KMEM_CACHE(test_slab, SLAB_PANIC)
      
      will create a new slab named "test_slab" of the size sizeof(struct
      test_slab) and aligned to the alignment of test slab.  If it fails then we
      panic.
      Signed-off-by: NChristoph Lameter <clameter@sgi.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0a31bd5f
    • C
      slab allocators: Remove obsolete SLAB_MUST_HWCACHE_ALIGN · 5af60839
      Christoph Lameter 提交于
      This patch was recently posted to lkml and acked by Pekka.
      
      The flag SLAB_MUST_HWCACHE_ALIGN is
      
      1. Never checked by SLAB at all.
      
      2. A duplicate of SLAB_HWCACHE_ALIGN for SLUB
      
      3. Fulfills the role of SLAB_HWCACHE_ALIGN for SLOB.
      
      The only remaining use is in sparc64 and ppc64 and their use there
      reflects some earlier role that the slab flag once may have had. If
      its specified then SLAB_HWCACHE_ALIGN is also specified.
      
      The flag is confusing, inconsistent and has no purpose.
      
      Remove it.
      Acked-by: NPekka Enberg <penberg@cs.helsinki.fi>
      Signed-off-by: NChristoph Lameter <clameter@sgi.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      5af60839
    • C
      SLUB core · 81819f0f
      Christoph Lameter 提交于
      This is a new slab allocator which was motivated by the complexity of the
      existing code in mm/slab.c. It attempts to address a variety of concerns
      with the existing implementation.
      
      A. Management of object queues
      
         A particular concern was the complex management of the numerous object
         queues in SLAB. SLUB has no such queues. Instead we dedicate a slab for
         each allocating CPU and use objects from a slab directly instead of
         queueing them up.
      
      B. Storage overhead of object queues
      
         SLAB Object queues exist per node, per CPU. The alien cache queue even
         has a queue array that contain a queue for each processor on each
         node. For very large systems the number of queues and the number of
         objects that may be caught in those queues grows exponentially. On our
         systems with 1k nodes / processors we have several gigabytes just tied up
         for storing references to objects for those queues  This does not include
         the objects that could be on those queues. One fears that the whole
         memory of the machine could one day be consumed by those queues.
      
      C. SLAB meta data overhead
      
         SLAB has overhead at the beginning of each slab. This means that data
         cannot be naturally aligned at the beginning of a slab block. SLUB keeps
         all meta data in the corresponding page_struct. Objects can be naturally
         aligned in the slab. F.e. a 128 byte object will be aligned at 128 byte
         boundaries and can fit tightly into a 4k page with no bytes left over.
         SLAB cannot do this.
      
      D. SLAB has a complex cache reaper
      
         SLUB does not need a cache reaper for UP systems. On SMP systems
         the per CPU slab may be pushed back into partial list but that
         operation is simple and does not require an iteration over a list
         of objects. SLAB expires per CPU, shared and alien object queues
         during cache reaping which may cause strange hold offs.
      
      E. SLAB has complex NUMA policy layer support
      
         SLUB pushes NUMA policy handling into the page allocator. This means that
         allocation is coarser (SLUB does interleave on a page level) but that
         situation was also present before 2.6.13. SLABs application of
         policies to individual slab objects allocated in SLAB is
         certainly a performance concern due to the frequent references to
         memory policies which may lead a sequence of objects to come from
         one node after another. SLUB will get a slab full of objects
         from one node and then will switch to the next.
      
      F. Reduction of the size of partial slab lists
      
         SLAB has per node partial lists. This means that over time a large
         number of partial slabs may accumulate on those lists. These can
         only be reused if allocator occur on specific nodes. SLUB has a global
         pool of partial slabs and will consume slabs from that pool to
         decrease fragmentation.
      
      G. Tunables
      
         SLAB has sophisticated tuning abilities for each slab cache. One can
         manipulate the queue sizes in detail. However, filling the queues still
         requires the uses of the spin lock to check out slabs. SLUB has a global
         parameter (min_slab_order) for tuning. Increasing the minimum slab
         order can decrease the locking overhead. The bigger the slab order the
         less motions of pages between per CPU and partial lists occur and the
         better SLUB will be scaling.
      
      G. Slab merging
      
         We often have slab caches with similar parameters. SLUB detects those
         on boot up and merges them into the corresponding general caches. This
         leads to more effective memory use. About 50% of all caches can
         be eliminated through slab merging. This will also decrease
         slab fragmentation because partial allocated slabs can be filled
         up again. Slab merging can be switched off by specifying
         slub_nomerge on boot up.
      
         Note that merging can expose heretofore unknown bugs in the kernel
         because corrupted objects may now be placed differently and corrupt
         differing neighboring objects. Enable sanity checks to find those.
      
      H. Diagnostics
      
         The current slab diagnostics are difficult to use and require a
         recompilation of the kernel. SLUB contains debugging code that
         is always available (but is kept out of the hot code paths).
         SLUB diagnostics can be enabled via the "slab_debug" option.
         Parameters can be specified to select a single or a group of
         slab caches for diagnostics. This means that the system is running
         with the usual performance and it is much more likely that
         race conditions can be reproduced.
      
      I. Resiliency
      
         If basic sanity checks are on then SLUB is capable of detecting
         common error conditions and recover as best as possible to allow the
         system to continue.
      
      J. Tracing
      
         Tracing can be enabled via the slab_debug=T,<slabcache> option
         during boot. SLUB will then protocol all actions on that slabcache
         and dump the object contents on free.
      
      K. On demand DMA cache creation.
      
         Generally DMA caches are not needed. If a kmalloc is used with
         __GFP_DMA then just create this single slabcache that is needed.
         For systems that have no ZONE_DMA requirement the support is
         completely eliminated.
      
      L. Performance increase
      
         Some benchmarks have shown speed improvements on kernbench in the
         range of 5-10%. The locking overhead of slub is based on the
         underlying base allocation size. If we can reliably allocate
         larger order pages then it is possible to increase slub
         performance much further. The anti-fragmentation patches may
         enable further performance increases.
      
      Tested on:
      i386 UP + SMP, x86_64 UP + SMP + NUMA emulation, IA64 NUMA + Simulator
      
      SLUB Boot options
      
      slub_nomerge		Disable merging of slabs
      slub_min_order=x	Require a minimum order for slab caches. This
      			increases the managed chunk size and therefore
      			reduces meta data and locking overhead.
      slub_min_objects=x	Mininum objects per slab. Default is 8.
      slub_max_order=x	Avoid generating slabs larger than order specified.
      slub_debug		Enable all diagnostics for all caches
      slub_debug=<options>	Enable selective options for all caches
      slub_debug=<o>,<cache>	Enable selective options for a certain set of
      			caches
      
      Available Debug options
      F		Double Free checking, sanity and resiliency
      R		Red zoning
      P		Object / padding poisoning
      U		Track last free / alloc
      T		Trace all allocs / frees (only use for individual slabs).
      
      To use SLUB: Apply this patch and then select SLUB as the default slab
      allocator.
      
      [hugh@veritas.com: fix an oops-causing locking error]
      [akpm@linux-foundation.org: various stupid cleanups and small fixes]
      Signed-off-by: NChristoph Lameter <clameter@sgi.com>
      Signed-off-by: NHugh Dickins <hugh@veritas.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      81819f0f
    • A
      mm/slab.c: proper prototypes · ac267728
      Adrian Bunk 提交于
      Add proper prototypes in include/linux/slab.h.
      Signed-off-by: NAdrian Bunk <bunk@stusta.de>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ac267728
    • P
      slab: introduce krealloc · fd76bab2
      Pekka Enberg 提交于
      This introduce krealloc() that reallocates memory while keeping the contents
      unchanged.  The allocator avoids reallocation if the new size fits the
      currently used cache.  I also added a simple non-optimized version for
      mm/slob.c for compatibility.
      
      [akpm@linux-foundation.org: fix warnings]
      Acked-by: NJosef Sipek <jsipek@fsl.cs.sunysb.edu>
      Acked-by: NMatt Mackall <mpm@selenic.com>
      Acked-by: NChristoph Lameter <clameter@sgi.com>
      Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      fd76bab2
  14. 14 12月, 2006 2 次提交
    • C
      [PATCH] More slab.h cleanups · 55935a34
      Christoph Lameter 提交于
      More cleanups for slab.h
      
      1. Remove tabs from weird locations as suggested by Pekka
      
      2. Drop the check for NUMA and SLAB_DEBUG from the fallback section
         as suggested by Pekka.
      
      3. Uses static inline for the fallback defs as also suggested by Pekka.
      
      4. Make kmem_ptr_valid take a const * argument.
      
      5. Separate the NUMA fallback definitions from the kmalloc_track fallback
         definitions.
      Signed-off-by: NChristoph Lameter <clameter@sgi.com>
      Cc: Pekka Enberg <penberg@cs.helsinki.fi>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      55935a34
    • C
      [PATCH] Cleanup slab headers / API to allow easy addition of new slab allocators · 2e892f43
      Christoph Lameter 提交于
      This is a response to an earlier discussion on linux-mm about splitting
      slab.h components per allocator.  Patch is against 2.6.19-git11.  See
      http://marc.theaimsgroup.com/?l=linux-mm&m=116469577431008&w=2
      
      This patch cleans up the slab header definitions.  We define the common
      functions of slob and slab in slab.h and put the extra definitions needed
      for slab's kmalloc implementations in <linux/slab_def.h>.  In order to get
      a greater set of common functions we add several empty functions to slob.c
      and also rename slob's kmalloc to __kmalloc.
      
      Slob does not need any special definitions since we introduce a fallback
      case.  If there is no need for a slab implementation to provide its own
      kmalloc mess^H^H^Hacros then we simply fall back to __kmalloc functions.
      That is sufficient for SLOB.
      
      Sort the function in slab.h according to their functionality.  First the
      functions operating on struct kmem_cache * then the kmalloc related
      functions followed by special debug and fallback definitions.
      
      Also redo a lot of comments.
      
      Signed-off-by: Christoph Lameter <clameter@sgi.com>?
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      2e892f43
  15. 08 12月, 2006 13 次提交