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+What: /sys/kernel/slab
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The /sys/kernel/slab directory contains a snapshot of the
+ internal state of the SLUB allocator for each cache. Certain
+ files may be modified to change the behavior of the cache (and
+ any cache it aliases, if any).
+Users: kernel memory tuning tools
+
+What: /sys/kernel/slab/cache/aliases
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The aliases file is read-only and specifies how many caches
+ have merged into this cache.
+
+What: /sys/kernel/slab/cache/align
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The align file is read-only and specifies the cache's object
+ alignment in bytes.
+
+What: /sys/kernel/slab/cache/alloc_calls
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The alloc_calls file is read-only and lists the kernel code
+ locations from which allocations for this cache were performed.
+ The alloc_calls file only contains information if debugging is
+ enabled for that cache (see Documentation/vm/slub.rst).
+
+What: /sys/kernel/slab/cache/alloc_fastpath
+Date: February 2008
+KernelVersion: 2.6.25
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The alloc_fastpath file shows how many objects have been
+ allocated using the fast path. It can be written to clear the
+ current count.
+ Available when CONFIG_SLUB_STATS is enabled.
+
+What: /sys/kernel/slab/cache/alloc_from_partial
+Date: February 2008
+KernelVersion: 2.6.25
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The alloc_from_partial file shows how many times a cpu slab has
+ been full and it has been refilled by using a slab from the list
+ of partially used slabs. It can be written to clear the current
+ count.
+ Available when CONFIG_SLUB_STATS is enabled.
+
+What: /sys/kernel/slab/cache/alloc_refill
+Date: February 2008
+KernelVersion: 2.6.25
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The alloc_refill file shows how many times the per-cpu freelist
+ was empty but there were objects available as the result of
+ remote cpu frees. It can be written to clear the current count.
+ Available when CONFIG_SLUB_STATS is enabled.
+
+What: /sys/kernel/slab/cache/alloc_slab
+Date: February 2008
+KernelVersion: 2.6.25
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The alloc_slab file is shows how many times a new slab had to
+ be allocated from the page allocator. It can be written to
+ clear the current count.
+ Available when CONFIG_SLUB_STATS is enabled.
+
+What: /sys/kernel/slab/cache/alloc_slowpath
+Date: February 2008
+KernelVersion: 2.6.25
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The alloc_slowpath file shows how many objects have been
+ allocated using the slow path because of a refill or
+ allocation from a partial or new slab. It can be written to
+ clear the current count.
+ Available when CONFIG_SLUB_STATS is enabled.
+
+What: /sys/kernel/slab/cache/cache_dma
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The cache_dma file is read-only and specifies whether objects
+ are from ZONE_DMA.
+ Available when CONFIG_ZONE_DMA is enabled.
+
+What: /sys/kernel/slab/cache/cpu_slabs
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The cpu_slabs file is read-only and displays how many cpu slabs
+ are active and their NUMA locality.
+
+What: /sys/kernel/slab/cache/cpuslab_flush
+Date: April 2009
+KernelVersion: 2.6.31
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The file cpuslab_flush shows how many times a cache's cpu slabs
+ have been flushed as the result of destroying or shrinking a
+ cache, a cpu going offline, or as the result of forcing an
+ allocation from a certain node. It can be written to clear the
+ current count.
+ Available when CONFIG_SLUB_STATS is enabled.
+
+What: /sys/kernel/slab/cache/ctor
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The ctor file is read-only and specifies the cache's object
+ constructor function, which is invoked for each object when a
+ new slab is allocated.
+
+What: /sys/kernel/slab/cache/deactivate_empty
+Date: February 2008
+KernelVersion: 2.6.25
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The deactivate_empty file shows how many times an empty cpu slab
+ was deactivated. It can be written to clear the current count.
+ Available when CONFIG_SLUB_STATS is enabled.
+
+What: /sys/kernel/slab/cache/deactivate_full
+Date: February 2008
+KernelVersion: 2.6.25
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The deactivate_full file shows how many times a full cpu slab
+ was deactivated. It can be written to clear the current count.
+ Available when CONFIG_SLUB_STATS is enabled.
+
+What: /sys/kernel/slab/cache/deactivate_remote_frees
+Date: February 2008
+KernelVersion: 2.6.25
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The deactivate_remote_frees file shows how many times a cpu slab
+ has been deactivated and contained free objects that were freed
+ remotely. It can be written to clear the current count.
+ Available when CONFIG_SLUB_STATS is enabled.
+
+What: /sys/kernel/slab/cache/deactivate_to_head
+Date: February 2008
+KernelVersion: 2.6.25
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The deactivate_to_head file shows how many times a partial cpu
+ slab was deactivated and added to the head of its node's partial
+ list. It can be written to clear the current count.
+ Available when CONFIG_SLUB_STATS is enabled.
+
+What: /sys/kernel/slab/cache/deactivate_to_tail
+Date: February 2008
+KernelVersion: 2.6.25
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The deactivate_to_tail file shows how many times a partial cpu
+ slab was deactivated and added to the tail of its node's partial
+ list. It can be written to clear the current count.
+ Available when CONFIG_SLUB_STATS is enabled.
+
+What: /sys/kernel/slab/cache/destroy_by_rcu
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The destroy_by_rcu file is read-only and specifies whether
+ slabs (not objects) are freed by rcu.
+
+What: /sys/kernel/slab/cache/free_add_partial
+Date: February 2008
+KernelVersion: 2.6.25
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The free_add_partial file shows how many times an object has
+ been freed in a full slab so that it had to added to its node's
+ partial list. It can be written to clear the current count.
+ Available when CONFIG_SLUB_STATS is enabled.
+
+What: /sys/kernel/slab/cache/free_calls
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The free_calls file is read-only and lists the locations of
+ object frees if slab debugging is enabled (see
+ Documentation/vm/slub.rst).
+
+What: /sys/kernel/slab/cache/free_fastpath
+Date: February 2008
+KernelVersion: 2.6.25
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The free_fastpath file shows how many objects have been freed
+ using the fast path because it was an object from the cpu slab.
+ It can be written to clear the current count.
+ Available when CONFIG_SLUB_STATS is enabled.
+
+What: /sys/kernel/slab/cache/free_frozen
+Date: February 2008
+KernelVersion: 2.6.25
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The free_frozen file shows how many objects have been freed to
+ a frozen slab (i.e. a remote cpu slab). It can be written to
+ clear the current count.
+ Available when CONFIG_SLUB_STATS is enabled.
+
+What: /sys/kernel/slab/cache/free_remove_partial
+Date: February 2008
+KernelVersion: 2.6.25
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The free_remove_partial file shows how many times an object has
+ been freed to a now-empty slab so that it had to be removed from
+ its node's partial list. It can be written to clear the current
+ count.
+ Available when CONFIG_SLUB_STATS is enabled.
+
+What: /sys/kernel/slab/cache/free_slab
+Date: February 2008
+KernelVersion: 2.6.25
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The free_slab file shows how many times an empty slab has been
+ freed back to the page allocator. It can be written to clear
+ the current count.
+ Available when CONFIG_SLUB_STATS is enabled.
+
+What: /sys/kernel/slab/cache/free_slowpath
+Date: February 2008
+KernelVersion: 2.6.25
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The free_slowpath file shows how many objects have been freed
+ using the slow path (i.e. to a full or partial slab). It can
+ be written to clear the current count.
+ Available when CONFIG_SLUB_STATS is enabled.
+
+What: /sys/kernel/slab/cache/hwcache_align
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The hwcache_align file is read-only and specifies whether
+ objects are aligned on cachelines.
+
+What: /sys/kernel/slab/cache/min_partial
+Date: February 2009
+KernelVersion: 2.6.30
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ David Rientjes <rientjes@google.com>
+Description:
+ The min_partial file specifies how many empty slabs shall
+ remain on a node's partial list to avoid the overhead of
+ allocating new slabs. Such slabs may be reclaimed by utilizing
+ the shrink file.
+
+What: /sys/kernel/slab/cache/object_size
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The object_size file is read-only and specifies the cache's
+ object size.
+
+What: /sys/kernel/slab/cache/objects
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The objects file is read-only and displays how many objects are
+ active and from which nodes they are from.
+
+What: /sys/kernel/slab/cache/objects_partial
+Date: April 2008
+KernelVersion: 2.6.26
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The objects_partial file is read-only and displays how many
+ objects are on partial slabs and from which nodes they are
+ from.
+
+What: /sys/kernel/slab/cache/objs_per_slab
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The file objs_per_slab is read-only and specifies how many
+ objects may be allocated from a single slab of the order
+ specified in /sys/kernel/slab/cache/order.
+
+What: /sys/kernel/slab/cache/order
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The order file specifies the page order at which new slabs are
+ allocated. It is writable and can be changed to increase the
+ number of objects per slab. If a slab cannot be allocated
+ because of fragmentation, SLUB will retry with the minimum order
+ possible depending on its characteristics.
+
+ When debug_guardpage_minorder=N (N > 0) parameter is specified
+ (see Documentation/admin-guide/kernel-parameters.rst), the minimum possible
+ order is used and this sysfs entry can not be used to change
+ the order at run time.
+
+What: /sys/kernel/slab/cache/order_fallback
+Date: April 2008
+KernelVersion: 2.6.26
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The order_fallback file shows how many times an allocation of a
+ new slab has not been possible at the cache's order and instead
+ fallen back to its minimum possible order. It can be written to
+ clear the current count.
+
+ Available when CONFIG_SLUB_STATS is enabled.
+
+What: /sys/kernel/slab/cache/partial
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The partial file is read-only and displays how long many
+ partial slabs there are and how long each node's list is.
+
+What: /sys/kernel/slab/cache/poison
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The poison file specifies whether objects should be poisoned
+ when a new slab is allocated.
+
+What: /sys/kernel/slab/cache/reclaim_account
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The reclaim_account file specifies whether the cache's objects
+ are reclaimable (and grouped by their mobility).
+
+What: /sys/kernel/slab/cache/red_zone
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The red_zone file specifies whether the cache's objects are red
+ zoned.
+
+What: /sys/kernel/slab/cache/remote_node_defrag_ratio
+Date: January 2008
+KernelVersion: 2.6.25
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The file remote_node_defrag_ratio specifies the percentage of
+ times SLUB will attempt to refill the cpu slab with a partial
+ slab from a remote node as opposed to allocating a new slab on
+ the local node. This reduces the amount of wasted memory over
+ the entire system but can be expensive.
+
+ Available when CONFIG_NUMA is enabled.
+
+What: /sys/kernel/slab/cache/sanity_checks
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The sanity_checks file specifies whether expensive checks
+ should be performed on free and, at minimum, enables double free
+ checks. Caches that enable sanity_checks cannot be merged with
+ caches that do not.
+
+What: /sys/kernel/slab/cache/shrink
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The shrink file is used to reclaim unused slab cache
+ memory from a cache. Empty per-cpu or partial slabs
+ are freed and the partial list is sorted so the slabs
+ with the fewest available objects are used first.
+ It only accepts a value of "1" on write for shrinking
+ the cache. Other input values are considered invalid.
+ Shrinking slab caches might be expensive and can
+ adversely impact other running applications. So it
+ should be used with care.
+
+What: /sys/kernel/slab/cache/slab_size
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The slab_size file is read-only and specifies the object size
+ with metadata (debugging information and alignment) in bytes.
+
+What: /sys/kernel/slab/cache/slabs
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The slabs file is read-only and displays how long many slabs
+ there are (both cpu and partial) and from which nodes they are
+ from.
+
+What: /sys/kernel/slab/cache/store_user
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The store_user file specifies whether the location of
+ allocation or free should be tracked for a cache.
+
+What: /sys/kernel/slab/cache/total_objects
+Date: April 2008
+KernelVersion: 2.6.26
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The total_objects file is read-only and displays how many total
+ objects a cache has and from which nodes they are from.
+
+What: /sys/kernel/slab/cache/trace
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ The trace file specifies whether object allocations and frees
+ should be traced.
+
+What: /sys/kernel/slab/cache/validate
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
+ Christoph Lameter <cl@linux-foundation.org>
+Description:
+ Writing to the validate file causes SLUB to traverse all of its
+ cache's objects and check the validity of metadata.