1 What: /sys/kernel/slab 1 What: /sys/kernel/slab
2 Date: May 2007 2 Date: May 2007
3 KernelVersion: 2.6.22 3 KernelVersion: 2.6.22
4 Contact: Pekka Enberg <penberg@cs.helsin 4 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
5 Christoph Lameter <cl@linux-fou 5 Christoph Lameter <cl@linux-foundation.org>
6 Description: 6 Description:
7 The /sys/kernel/slab directory 7 The /sys/kernel/slab directory contains a snapshot of the
8 internal state of the SLUB all 8 internal state of the SLUB allocator for each cache. Certain
9 files may be modified to chang 9 files may be modified to change the behavior of the cache (and
10 any cache it aliases, if any). 10 any cache it aliases, if any).
11 Users: kernel memory tuning tools 11 Users: kernel memory tuning tools
12 12
13 What: /sys/kernel/slab/<cache>/alias 13 What: /sys/kernel/slab/<cache>/aliases
14 Date: May 2007 14 Date: May 2007
15 KernelVersion: 2.6.22 15 KernelVersion: 2.6.22
16 Contact: Pekka Enberg <penberg@cs.helsin 16 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
17 Christoph Lameter <cl@linux-fou 17 Christoph Lameter <cl@linux-foundation.org>
18 Description: 18 Description:
19 The aliases file is read-only 19 The aliases file is read-only and specifies how many caches
20 have merged into this cache. 20 have merged into this cache.
21 21
22 What: /sys/kernel/slab/<cache>/align 22 What: /sys/kernel/slab/<cache>/align
23 Date: May 2007 23 Date: May 2007
24 KernelVersion: 2.6.22 24 KernelVersion: 2.6.22
25 Contact: Pekka Enberg <penberg@cs.helsin 25 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
26 Christoph Lameter <cl@linux-fou 26 Christoph Lameter <cl@linux-foundation.org>
27 Description: 27 Description:
28 The align file is read-only an 28 The align file is read-only and specifies the cache's object
29 alignment in bytes. 29 alignment in bytes.
30 30
31 What: /sys/kernel/slab/<cache>/alloc 31 What: /sys/kernel/slab/<cache>/alloc_calls
32 Date: May 2007 32 Date: May 2007
33 KernelVersion: 2.6.22 33 KernelVersion: 2.6.22
34 Contact: Pekka Enberg <penberg@cs.helsin 34 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
35 Christoph Lameter <cl@linux-fou 35 Christoph Lameter <cl@linux-foundation.org>
36 Description: 36 Description:
37 The alloc_calls file is read-o 37 The alloc_calls file is read-only and lists the kernel code
38 locations from which allocatio 38 locations from which allocations for this cache were performed.
39 The alloc_calls file only cont 39 The alloc_calls file only contains information if debugging is
40 enabled for that cache (see Do 40 enabled for that cache (see Documentation/mm/slub.rst).
41 41
42 What: /sys/kernel/slab/<cache>/alloc 42 What: /sys/kernel/slab/<cache>/alloc_fastpath
43 Date: February 2008 43 Date: February 2008
44 KernelVersion: 2.6.25 44 KernelVersion: 2.6.25
45 Contact: Pekka Enberg <penberg@cs.helsin 45 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
46 Christoph Lameter <cl@linux-fou 46 Christoph Lameter <cl@linux-foundation.org>
47 Description: 47 Description:
48 The alloc_fastpath file shows 48 The alloc_fastpath file shows how many objects have been
49 allocated using the fast path. 49 allocated using the fast path. It can be written to clear the
50 current count. 50 current count.
51 Available when CONFIG_SLUB_STA 51 Available when CONFIG_SLUB_STATS is enabled.
52 52
53 What: /sys/kernel/slab/<cache>/alloc 53 What: /sys/kernel/slab/<cache>/alloc_from_partial
54 Date: February 2008 54 Date: February 2008
55 KernelVersion: 2.6.25 55 KernelVersion: 2.6.25
56 Contact: Pekka Enberg <penberg@cs.helsin 56 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
57 Christoph Lameter <cl@linux-fou 57 Christoph Lameter <cl@linux-foundation.org>
58 Description: 58 Description:
59 The alloc_from_partial file sh 59 The alloc_from_partial file shows how many times a cpu slab has
60 been full and it has been refi 60 been full and it has been refilled by using a slab from the list
61 of partially used slabs. It c 61 of partially used slabs. It can be written to clear the current
62 count. 62 count.
63 Available when CONFIG_SLUB_STA 63 Available when CONFIG_SLUB_STATS is enabled.
64 64
65 What: /sys/kernel/slab/<cache>/alloc 65 What: /sys/kernel/slab/<cache>/alloc_refill
66 Date: February 2008 66 Date: February 2008
67 KernelVersion: 2.6.25 67 KernelVersion: 2.6.25
68 Contact: Pekka Enberg <penberg@cs.helsin 68 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
69 Christoph Lameter <cl@linux-fou 69 Christoph Lameter <cl@linux-foundation.org>
70 Description: 70 Description:
71 The alloc_refill file shows ho 71 The alloc_refill file shows how many times the per-cpu freelist
72 was empty but there were objec 72 was empty but there were objects available as the result of
73 remote cpu frees. It can be w 73 remote cpu frees. It can be written to clear the current count.
74 Available when CONFIG_SLUB_STA 74 Available when CONFIG_SLUB_STATS is enabled.
75 75
76 What: /sys/kernel/slab/<cache>/alloc 76 What: /sys/kernel/slab/<cache>/alloc_slab
77 Date: February 2008 77 Date: February 2008
78 KernelVersion: 2.6.25 78 KernelVersion: 2.6.25
79 Contact: Pekka Enberg <penberg@cs.helsin 79 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
80 Christoph Lameter <cl@linux-fou 80 Christoph Lameter <cl@linux-foundation.org>
81 Description: 81 Description:
82 The alloc_slab file is shows h 82 The alloc_slab file is shows how many times a new slab had to
83 be allocated from the page all 83 be allocated from the page allocator. It can be written to
84 clear the current count. 84 clear the current count.
85 Available when CONFIG_SLUB_STA 85 Available when CONFIG_SLUB_STATS is enabled.
86 86
87 What: /sys/kernel/slab/<cache>/alloc 87 What: /sys/kernel/slab/<cache>/alloc_slowpath
88 Date: February 2008 88 Date: February 2008
89 KernelVersion: 2.6.25 89 KernelVersion: 2.6.25
90 Contact: Pekka Enberg <penberg@cs.helsin 90 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
91 Christoph Lameter <cl@linux-fou 91 Christoph Lameter <cl@linux-foundation.org>
92 Description: 92 Description:
93 The alloc_slowpath file shows 93 The alloc_slowpath file shows how many objects have been
94 allocated using the slow path 94 allocated using the slow path because of a refill or
95 allocation from a partial or n 95 allocation from a partial or new slab. It can be written to
96 clear the current count. 96 clear the current count.
97 Available when CONFIG_SLUB_STA 97 Available when CONFIG_SLUB_STATS is enabled.
98 98
99 What: /sys/kernel/slab/<cache>/cache 99 What: /sys/kernel/slab/<cache>/cache_dma
100 Date: May 2007 100 Date: May 2007
101 KernelVersion: 2.6.22 101 KernelVersion: 2.6.22
102 Contact: Pekka Enberg <penberg@cs.helsin 102 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
103 Christoph Lameter <cl@linux-fou 103 Christoph Lameter <cl@linux-foundation.org>
104 Description: 104 Description:
105 The cache_dma file is read-onl 105 The cache_dma file is read-only and specifies whether objects
106 are from ZONE_DMA. 106 are from ZONE_DMA.
107 Available when CONFIG_ZONE_DMA 107 Available when CONFIG_ZONE_DMA is enabled.
108 108
109 What: /sys/kernel/slab/<cache>/cpu_s 109 What: /sys/kernel/slab/<cache>/cpu_slabs
110 Date: May 2007 110 Date: May 2007
111 KernelVersion: 2.6.22 111 KernelVersion: 2.6.22
112 Contact: Pekka Enberg <penberg@cs.helsin 112 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
113 Christoph Lameter <cl@linux-fou 113 Christoph Lameter <cl@linux-foundation.org>
114 Description: 114 Description:
115 The cpu_slabs file is read-onl 115 The cpu_slabs file is read-only and displays how many cpu slabs
116 are active and their NUMA loca 116 are active and their NUMA locality.
117 117
118 What: /sys/kernel/slab/<cache>/cpusl 118 What: /sys/kernel/slab/<cache>/cpuslab_flush
119 Date: April 2009 119 Date: April 2009
120 KernelVersion: 2.6.31 120 KernelVersion: 2.6.31
121 Contact: Pekka Enberg <penberg@cs.helsin 121 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
122 Christoph Lameter <cl@linux-fou 122 Christoph Lameter <cl@linux-foundation.org>
123 Description: 123 Description:
124 The file cpuslab_flush shows h 124 The file cpuslab_flush shows how many times a cache's cpu slabs
125 have been flushed as the resul 125 have been flushed as the result of destroying or shrinking a
126 cache, a cpu going offline, or 126 cache, a cpu going offline, or as the result of forcing an
127 allocation from a certain node 127 allocation from a certain node. It can be written to clear the
128 current count. 128 current count.
129 Available when CONFIG_SLUB_STA 129 Available when CONFIG_SLUB_STATS is enabled.
130 130
131 What: /sys/kernel/slab/<cache>/ctor 131 What: /sys/kernel/slab/<cache>/ctor
132 Date: May 2007 132 Date: May 2007
133 KernelVersion: 2.6.22 133 KernelVersion: 2.6.22
134 Contact: Pekka Enberg <penberg@cs.helsin 134 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
135 Christoph Lameter <cl@linux-fou 135 Christoph Lameter <cl@linux-foundation.org>
136 Description: 136 Description:
137 The ctor file is read-only and 137 The ctor file is read-only and specifies the cache's object
138 constructor function, which is 138 constructor function, which is invoked for each object when a
139 new slab is allocated. 139 new slab is allocated.
140 140
141 What: /sys/kernel/slab/<cache>/deact 141 What: /sys/kernel/slab/<cache>/deactivate_empty
142 Date: February 2008 142 Date: February 2008
143 KernelVersion: 2.6.25 143 KernelVersion: 2.6.25
144 Contact: Pekka Enberg <penberg@cs.helsin 144 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
145 Christoph Lameter <cl@linux-fou 145 Christoph Lameter <cl@linux-foundation.org>
146 Description: 146 Description:
147 The deactivate_empty file show 147 The deactivate_empty file shows how many times an empty cpu slab
148 was deactivated. It can be wr 148 was deactivated. It can be written to clear the current count.
149 Available when CONFIG_SLUB_STA 149 Available when CONFIG_SLUB_STATS is enabled.
150 150
151 What: /sys/kernel/slab/<cache>/deact 151 What: /sys/kernel/slab/<cache>/deactivate_full
152 Date: February 2008 152 Date: February 2008
153 KernelVersion: 2.6.25 153 KernelVersion: 2.6.25
154 Contact: Pekka Enberg <penberg@cs.helsin 154 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
155 Christoph Lameter <cl@linux-fou 155 Christoph Lameter <cl@linux-foundation.org>
156 Description: 156 Description:
157 The deactivate_full file shows 157 The deactivate_full file shows how many times a full cpu slab
158 was deactivated. It can be wr 158 was deactivated. It can be written to clear the current count.
159 Available when CONFIG_SLUB_STA 159 Available when CONFIG_SLUB_STATS is enabled.
160 160
161 What: /sys/kernel/slab/<cache>/deact 161 What: /sys/kernel/slab/<cache>/deactivate_remote_frees
162 Date: February 2008 162 Date: February 2008
163 KernelVersion: 2.6.25 163 KernelVersion: 2.6.25
164 Contact: Pekka Enberg <penberg@cs.helsin 164 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
165 Christoph Lameter <cl@linux-fou 165 Christoph Lameter <cl@linux-foundation.org>
166 Description: 166 Description:
167 The deactivate_remote_frees fi 167 The deactivate_remote_frees file shows how many times a cpu slab
168 has been deactivated and conta 168 has been deactivated and contained free objects that were freed
169 remotely. It can be written t 169 remotely. It can be written to clear the current count.
170 Available when CONFIG_SLUB_STA 170 Available when CONFIG_SLUB_STATS is enabled.
171 171
172 What: /sys/kernel/slab/<cache>/deact 172 What: /sys/kernel/slab/<cache>/deactivate_to_head
173 Date: February 2008 173 Date: February 2008
174 KernelVersion: 2.6.25 174 KernelVersion: 2.6.25
175 Contact: Pekka Enberg <penberg@cs.helsin 175 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
176 Christoph Lameter <cl@linux-fou 176 Christoph Lameter <cl@linux-foundation.org>
177 Description: 177 Description:
178 The deactivate_to_head file sh 178 The deactivate_to_head file shows how many times a partial cpu
179 slab was deactivated and added 179 slab was deactivated and added to the head of its node's partial
180 list. It can be written to cl 180 list. It can be written to clear the current count.
181 Available when CONFIG_SLUB_STA 181 Available when CONFIG_SLUB_STATS is enabled.
182 182
183 What: /sys/kernel/slab/<cache>/deact 183 What: /sys/kernel/slab/<cache>/deactivate_to_tail
184 Date: February 2008 184 Date: February 2008
185 KernelVersion: 2.6.25 185 KernelVersion: 2.6.25
186 Contact: Pekka Enberg <penberg@cs.helsin 186 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
187 Christoph Lameter <cl@linux-fou 187 Christoph Lameter <cl@linux-foundation.org>
188 Description: 188 Description:
189 The deactivate_to_tail file sh 189 The deactivate_to_tail file shows how many times a partial cpu
190 slab was deactivated and added 190 slab was deactivated and added to the tail of its node's partial
191 list. It can be written to cl 191 list. It can be written to clear the current count.
192 Available when CONFIG_SLUB_STA 192 Available when CONFIG_SLUB_STATS is enabled.
193 193
194 What: /sys/kernel/slab/<cache>/destr 194 What: /sys/kernel/slab/<cache>/destroy_by_rcu
195 Date: May 2007 195 Date: May 2007
196 KernelVersion: 2.6.22 196 KernelVersion: 2.6.22
197 Contact: Pekka Enberg <penberg@cs.helsin 197 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
198 Christoph Lameter <cl@linux-fou 198 Christoph Lameter <cl@linux-foundation.org>
199 Description: 199 Description:
200 The destroy_by_rcu file is rea 200 The destroy_by_rcu file is read-only and specifies whether
201 slabs (not objects) are freed 201 slabs (not objects) are freed by rcu.
202 202
203 What: /sys/kernel/slab/<cache>/free_ 203 What: /sys/kernel/slab/<cache>/free_add_partial
204 Date: February 2008 204 Date: February 2008
205 KernelVersion: 2.6.25 205 KernelVersion: 2.6.25
206 Contact: Pekka Enberg <penberg@cs.helsin 206 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
207 Christoph Lameter <cl@linux-fou 207 Christoph Lameter <cl@linux-foundation.org>
208 Description: 208 Description:
209 The free_add_partial file show 209 The free_add_partial file shows how many times an object has
210 been freed in a full slab so t 210 been freed in a full slab so that it had to added to its node's
211 partial list. It can be writt 211 partial list. It can be written to clear the current count.
212 Available when CONFIG_SLUB_STA 212 Available when CONFIG_SLUB_STATS is enabled.
213 213
214 What: /sys/kernel/slab/<cache>/free_ 214 What: /sys/kernel/slab/<cache>/free_calls
215 Date: May 2007 215 Date: May 2007
216 KernelVersion: 2.6.22 216 KernelVersion: 2.6.22
217 Contact: Pekka Enberg <penberg@cs.helsin 217 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
218 Christoph Lameter <cl@linux-fou 218 Christoph Lameter <cl@linux-foundation.org>
219 Description: 219 Description:
220 The free_calls file is read-on 220 The free_calls file is read-only and lists the locations of
221 object frees if slab debugging 221 object frees if slab debugging is enabled (see
222 Documentation/mm/slub.rst). 222 Documentation/mm/slub.rst).
223 223
224 What: /sys/kernel/slab/<cache>/free_ 224 What: /sys/kernel/slab/<cache>/free_fastpath
225 Date: February 2008 225 Date: February 2008
226 KernelVersion: 2.6.25 226 KernelVersion: 2.6.25
227 Contact: Pekka Enberg <penberg@cs.helsin 227 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
228 Christoph Lameter <cl@linux-fou 228 Christoph Lameter <cl@linux-foundation.org>
229 Description: 229 Description:
230 The free_fastpath file shows h 230 The free_fastpath file shows how many objects have been freed
231 using the fast path because it 231 using the fast path because it was an object from the cpu slab.
232 It can be written to clear the 232 It can be written to clear the current count.
233 Available when CONFIG_SLUB_STA 233 Available when CONFIG_SLUB_STATS is enabled.
234 234
235 What: /sys/kernel/slab/<cache>/free_ 235 What: /sys/kernel/slab/<cache>/free_frozen
236 Date: February 2008 236 Date: February 2008
237 KernelVersion: 2.6.25 237 KernelVersion: 2.6.25
238 Contact: Pekka Enberg <penberg@cs.helsin 238 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
239 Christoph Lameter <cl@linux-fou 239 Christoph Lameter <cl@linux-foundation.org>
240 Description: 240 Description:
241 The free_frozen file shows how 241 The free_frozen file shows how many objects have been freed to
242 a frozen slab (i.e. a remote c 242 a frozen slab (i.e. a remote cpu slab). It can be written to
243 clear the current count. 243 clear the current count.
244 Available when CONFIG_SLUB_STA 244 Available when CONFIG_SLUB_STATS is enabled.
245 245
246 What: /sys/kernel/slab/<cache>/free_ 246 What: /sys/kernel/slab/<cache>/free_remove_partial
247 Date: February 2008 247 Date: February 2008
248 KernelVersion: 2.6.25 248 KernelVersion: 2.6.25
249 Contact: Pekka Enberg <penberg@cs.helsin 249 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
250 Christoph Lameter <cl@linux-fou 250 Christoph Lameter <cl@linux-foundation.org>
251 Description: 251 Description:
252 The free_remove_partial file s 252 The free_remove_partial file shows how many times an object has
253 been freed to a now-empty slab 253 been freed to a now-empty slab so that it had to be removed from
254 its node's partial list. It c 254 its node's partial list. It can be written to clear the current
255 count. 255 count.
256 Available when CONFIG_SLUB_STA 256 Available when CONFIG_SLUB_STATS is enabled.
257 257
258 What: /sys/kernel/slab/<cache>/free_ 258 What: /sys/kernel/slab/<cache>/free_slab
259 Date: February 2008 259 Date: February 2008
260 KernelVersion: 2.6.25 260 KernelVersion: 2.6.25
261 Contact: Pekka Enberg <penberg@cs.helsin 261 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
262 Christoph Lameter <cl@linux-fou 262 Christoph Lameter <cl@linux-foundation.org>
263 Description: 263 Description:
264 The free_slab file shows how m 264 The free_slab file shows how many times an empty slab has been
265 freed back to the page allocat 265 freed back to the page allocator. It can be written to clear
266 the current count. 266 the current count.
267 Available when CONFIG_SLUB_STA 267 Available when CONFIG_SLUB_STATS is enabled.
268 268
269 What: /sys/kernel/slab/<cache>/free_ 269 What: /sys/kernel/slab/<cache>/free_slowpath
270 Date: February 2008 270 Date: February 2008
271 KernelVersion: 2.6.25 271 KernelVersion: 2.6.25
272 Contact: Pekka Enberg <penberg@cs.helsin 272 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
273 Christoph Lameter <cl@linux-fou 273 Christoph Lameter <cl@linux-foundation.org>
274 Description: 274 Description:
275 The free_slowpath file shows h 275 The free_slowpath file shows how many objects have been freed
276 using the slow path (i.e. to a 276 using the slow path (i.e. to a full or partial slab). It can
277 be written to clear the curren 277 be written to clear the current count.
278 Available when CONFIG_SLUB_STA 278 Available when CONFIG_SLUB_STATS is enabled.
279 279
280 What: /sys/kernel/slab/<cache>/hwcac 280 What: /sys/kernel/slab/<cache>/hwcache_align
281 Date: May 2007 281 Date: May 2007
282 KernelVersion: 2.6.22 282 KernelVersion: 2.6.22
283 Contact: Pekka Enberg <penberg@cs.helsin 283 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
284 Christoph Lameter <cl@linux-fou 284 Christoph Lameter <cl@linux-foundation.org>
285 Description: 285 Description:
286 The hwcache_align file is read 286 The hwcache_align file is read-only and specifies whether
287 objects are aligned on cacheli 287 objects are aligned on cachelines.
288 288
289 What: /sys/kernel/slab/<cache>/min_p 289 What: /sys/kernel/slab/<cache>/min_partial
290 Date: February 2009 290 Date: February 2009
291 KernelVersion: 2.6.30 291 KernelVersion: 2.6.30
292 Contact: Pekka Enberg <penberg@cs.helsin 292 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
293 David Rientjes <rientjes@google 293 David Rientjes <rientjes@google.com>
294 Description: 294 Description:
295 The min_partial file specifies 295 The min_partial file specifies how many empty slabs shall
296 remain on a node's partial lis 296 remain on a node's partial list to avoid the overhead of
297 allocating new slabs. Such sl 297 allocating new slabs. Such slabs may be reclaimed by utilizing
298 the shrink file. 298 the shrink file.
299 299
300 What: /sys/kernel/slab/<cache>/objec 300 What: /sys/kernel/slab/<cache>/object_size
301 Date: May 2007 301 Date: May 2007
302 KernelVersion: 2.6.22 302 KernelVersion: 2.6.22
303 Contact: Pekka Enberg <penberg@cs.helsin 303 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
304 Christoph Lameter <cl@linux-fou 304 Christoph Lameter <cl@linux-foundation.org>
305 Description: 305 Description:
306 The object_size file is read-o 306 The object_size file is read-only and specifies the cache's
307 object size. 307 object size.
308 308
309 What: /sys/kernel/slab/<cache>/objec 309 What: /sys/kernel/slab/<cache>/objects
310 Date: May 2007 310 Date: May 2007
311 KernelVersion: 2.6.22 311 KernelVersion: 2.6.22
312 Contact: Pekka Enberg <penberg@cs.helsin 312 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
313 Christoph Lameter <cl@linux-fou 313 Christoph Lameter <cl@linux-foundation.org>
314 Description: 314 Description:
315 The objects file is read-only 315 The objects file is read-only and displays how many objects are
316 active and from which nodes th 316 active and from which nodes they are from.
317 317
318 What: /sys/kernel/slab/<cache>/objec 318 What: /sys/kernel/slab/<cache>/objects_partial
319 Date: April 2008 319 Date: April 2008
320 KernelVersion: 2.6.26 320 KernelVersion: 2.6.26
321 Contact: Pekka Enberg <penberg@cs.helsin 321 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
322 Christoph Lameter <cl@linux-fou 322 Christoph Lameter <cl@linux-foundation.org>
323 Description: 323 Description:
324 The objects_partial file is re 324 The objects_partial file is read-only and displays how many
325 objects are on partial slabs a 325 objects are on partial slabs and from which nodes they are
326 from. 326 from.
327 327
328 What: /sys/kernel/slab/<cache>/objs_ 328 What: /sys/kernel/slab/<cache>/objs_per_slab
329 Date: May 2007 329 Date: May 2007
330 KernelVersion: 2.6.22 330 KernelVersion: 2.6.22
331 Contact: Pekka Enberg <penberg@cs.helsin 331 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
332 Christoph Lameter <cl@linux-fou 332 Christoph Lameter <cl@linux-foundation.org>
333 Description: 333 Description:
334 The file objs_per_slab is read 334 The file objs_per_slab is read-only and specifies how many
335 objects may be allocated from 335 objects may be allocated from a single slab of the order
336 specified in /sys/kernel/slab/ 336 specified in /sys/kernel/slab/<cache>/order.
337 337
338 What: /sys/kernel/slab/<cache>/order 338 What: /sys/kernel/slab/<cache>/order
339 Date: May 2007 339 Date: May 2007
340 KernelVersion: 2.6.22 340 KernelVersion: 2.6.22
341 Contact: Pekka Enberg <penberg@cs.helsin 341 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
342 Christoph Lameter <cl@linux-fou 342 Christoph Lameter <cl@linux-foundation.org>
343 Description: 343 Description:
344 The order file specifies the p 344 The order file specifies the page order at which new slabs are
345 allocated. It is writable and 345 allocated. It is writable and can be changed to increase the
346 number of objects per slab. I 346 number of objects per slab. If a slab cannot be allocated
347 because of fragmentation, SLUB 347 because of fragmentation, SLUB will retry with the minimum order
348 possible depending on its char 348 possible depending on its characteristics.
349 349
350 When debug_guardpage_minorder= 350 When debug_guardpage_minorder=N (N > 0) parameter is specified
351 (see Documentation/admin-guide 351 (see Documentation/admin-guide/kernel-parameters.rst), the minimum possible
352 order is used and this sysfs e 352 order is used and this sysfs entry can not be used to change
353 the order at run time. 353 the order at run time.
354 354
355 What: /sys/kernel/slab/<cache>/order 355 What: /sys/kernel/slab/<cache>/order_fallback
356 Date: April 2008 356 Date: April 2008
357 KernelVersion: 2.6.26 357 KernelVersion: 2.6.26
358 Contact: Pekka Enberg <penberg@cs.helsin 358 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
359 Christoph Lameter <cl@linux-fou 359 Christoph Lameter <cl@linux-foundation.org>
360 Description: 360 Description:
361 The order_fallback file shows 361 The order_fallback file shows how many times an allocation of a
362 new slab has not been possible 362 new slab has not been possible at the cache's order and instead
363 fallen back to its minimum pos 363 fallen back to its minimum possible order. It can be written to
364 clear the current count. 364 clear the current count.
365 365
366 Available when CONFIG_SLUB_STA 366 Available when CONFIG_SLUB_STATS is enabled.
367 367
368 What: /sys/kernel/slab/<cache>/parti 368 What: /sys/kernel/slab/<cache>/partial
369 Date: May 2007 369 Date: May 2007
370 KernelVersion: 2.6.22 370 KernelVersion: 2.6.22
371 Contact: Pekka Enberg <penberg@cs.helsin 371 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
372 Christoph Lameter <cl@linux-fou 372 Christoph Lameter <cl@linux-foundation.org>
373 Description: 373 Description:
374 The partial file is read-only 374 The partial file is read-only and displays how long many
375 partial slabs there are and ho 375 partial slabs there are and how long each node's list is.
376 376
377 What: /sys/kernel/slab/<cache>/poiso 377 What: /sys/kernel/slab/<cache>/poison
378 Date: May 2007 378 Date: May 2007
379 KernelVersion: 2.6.22 379 KernelVersion: 2.6.22
380 Contact: Pekka Enberg <penberg@cs.helsin 380 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
381 Christoph Lameter <cl@linux-fou 381 Christoph Lameter <cl@linux-foundation.org>
382 Description: 382 Description:
383 The poison file specifies whet 383 The poison file specifies whether objects should be poisoned
384 when a new slab is allocated. 384 when a new slab is allocated.
385 385
386 What: /sys/kernel/slab/<cache>/recla 386 What: /sys/kernel/slab/<cache>/reclaim_account
387 Date: May 2007 387 Date: May 2007
388 KernelVersion: 2.6.22 388 KernelVersion: 2.6.22
389 Contact: Pekka Enberg <penberg@cs.helsin 389 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
390 Christoph Lameter <cl@linux-fou 390 Christoph Lameter <cl@linux-foundation.org>
391 Description: 391 Description:
392 The reclaim_account file speci 392 The reclaim_account file specifies whether the cache's objects
393 are reclaimable (and grouped b 393 are reclaimable (and grouped by their mobility).
394 394
395 What: /sys/kernel/slab/<cache>/red_z 395 What: /sys/kernel/slab/<cache>/red_zone
396 Date: May 2007 396 Date: May 2007
397 KernelVersion: 2.6.22 397 KernelVersion: 2.6.22
398 Contact: Pekka Enberg <penberg@cs.helsin 398 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
399 Christoph Lameter <cl@linux-fou 399 Christoph Lameter <cl@linux-foundation.org>
400 Description: 400 Description:
401 The red_zone file specifies wh 401 The red_zone file specifies whether the cache's objects are red
402 zoned. 402 zoned.
403 403
404 What: /sys/kernel/slab/<cache>/remot 404 What: /sys/kernel/slab/<cache>/remote_node_defrag_ratio
405 Date: January 2008 405 Date: January 2008
406 KernelVersion: 2.6.25 406 KernelVersion: 2.6.25
407 Contact: Pekka Enberg <penberg@cs.helsin 407 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
408 Christoph Lameter <cl@linux-fou 408 Christoph Lameter <cl@linux-foundation.org>
409 Description: 409 Description:
410 The file remote_node_defrag_ra 410 The file remote_node_defrag_ratio specifies the percentage of
411 times SLUB will attempt to ref 411 times SLUB will attempt to refill the cpu slab with a partial
412 slab from a remote node as opp 412 slab from a remote node as opposed to allocating a new slab on
413 the local node. This reduces 413 the local node. This reduces the amount of wasted memory over
414 the entire system but can be e 414 the entire system but can be expensive.
415 415
416 Available when CONFIG_NUMA is 416 Available when CONFIG_NUMA is enabled.
417 417
418 What: /sys/kernel/slab/<cache>/sanit 418 What: /sys/kernel/slab/<cache>/sanity_checks
419 Date: May 2007 419 Date: May 2007
420 KernelVersion: 2.6.22 420 KernelVersion: 2.6.22
421 Contact: Pekka Enberg <penberg@cs.helsin 421 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
422 Christoph Lameter <cl@linux-fou 422 Christoph Lameter <cl@linux-foundation.org>
423 Description: 423 Description:
424 The sanity_checks file specifi 424 The sanity_checks file specifies whether expensive checks
425 should be performed on free an 425 should be performed on free and, at minimum, enables double free
426 checks. Caches that enable sa 426 checks. Caches that enable sanity_checks cannot be merged with
427 caches that do not. 427 caches that do not.
428 428
429 What: /sys/kernel/slab/<cache>/shrin 429 What: /sys/kernel/slab/<cache>/shrink
430 Date: May 2007 430 Date: May 2007
431 KernelVersion: 2.6.22 431 KernelVersion: 2.6.22
432 Contact: Pekka Enberg <penberg@cs.helsin 432 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
433 Christoph Lameter <cl@linux-fou 433 Christoph Lameter <cl@linux-foundation.org>
434 Description: 434 Description:
435 The shrink file is used to rec 435 The shrink file is used to reclaim unused slab cache
436 memory from a cache. Empty pe 436 memory from a cache. Empty per-cpu or partial slabs
437 are freed and the partial list 437 are freed and the partial list is sorted so the slabs
438 with the fewest available obje 438 with the fewest available objects are used first.
439 It only accepts a value of "1" 439 It only accepts a value of "1" on write for shrinking
440 the cache. Other input values 440 the cache. Other input values are considered invalid.
441 Shrinking slab caches might be 441 Shrinking slab caches might be expensive and can
442 adversely impact other running 442 adversely impact other running applications. So it
443 should be used with care. 443 should be used with care.
444 444
445 What: /sys/kernel/slab/<cache>/slab_ 445 What: /sys/kernel/slab/<cache>/slab_size
446 Date: May 2007 446 Date: May 2007
447 KernelVersion: 2.6.22 447 KernelVersion: 2.6.22
448 Contact: Pekka Enberg <penberg@cs.helsin 448 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
449 Christoph Lameter <cl@linux-fou 449 Christoph Lameter <cl@linux-foundation.org>
450 Description: 450 Description:
451 The slab_size file is read-onl 451 The slab_size file is read-only and specifies the object size
452 with metadata (debugging infor 452 with metadata (debugging information and alignment) in bytes.
453 453
454 What: /sys/kernel/slab/<cache>/slabs 454 What: /sys/kernel/slab/<cache>/slabs
455 Date: May 2007 455 Date: May 2007
456 KernelVersion: 2.6.22 456 KernelVersion: 2.6.22
457 Contact: Pekka Enberg <penberg@cs.helsin 457 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
458 Christoph Lameter <cl@linux-fou 458 Christoph Lameter <cl@linux-foundation.org>
459 Description: 459 Description:
460 The slabs file is read-only an 460 The slabs file is read-only and displays how long many slabs
461 there are (both cpu and partia 461 there are (both cpu and partial) and from which nodes they are
462 from. 462 from.
463 463
464 What: /sys/kernel/slab/<cache>/store 464 What: /sys/kernel/slab/<cache>/store_user
465 Date: May 2007 465 Date: May 2007
466 KernelVersion: 2.6.22 466 KernelVersion: 2.6.22
467 Contact: Pekka Enberg <penberg@cs.helsin 467 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
468 Christoph Lameter <cl@linux-fou 468 Christoph Lameter <cl@linux-foundation.org>
469 Description: 469 Description:
470 The store_user file specifies 470 The store_user file specifies whether the location of
471 allocation or free should be t 471 allocation or free should be tracked for a cache.
472 472
473 What: /sys/kernel/slab/<cache>/total 473 What: /sys/kernel/slab/<cache>/total_objects
474 Date: April 2008 474 Date: April 2008
475 KernelVersion: 2.6.26 475 KernelVersion: 2.6.26
476 Contact: Pekka Enberg <penberg@cs.helsin 476 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
477 Christoph Lameter <cl@linux-fou 477 Christoph Lameter <cl@linux-foundation.org>
478 Description: 478 Description:
479 The total_objects file is read 479 The total_objects file is read-only and displays how many total
480 objects a cache has and from w 480 objects a cache has and from which nodes they are from.
481 481
482 What: /sys/kernel/slab/<cache>/trace 482 What: /sys/kernel/slab/<cache>/trace
483 Date: May 2007 483 Date: May 2007
484 KernelVersion: 2.6.22 484 KernelVersion: 2.6.22
485 Contact: Pekka Enberg <penberg@cs.helsin 485 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
486 Christoph Lameter <cl@linux-fou 486 Christoph Lameter <cl@linux-foundation.org>
487 Description: 487 Description:
488 The trace file specifies wheth 488 The trace file specifies whether object allocations and frees
489 should be traced. 489 should be traced.
490 490
491 What: /sys/kernel/slab/<cache>/valid 491 What: /sys/kernel/slab/<cache>/validate
492 Date: May 2007 492 Date: May 2007
493 KernelVersion: 2.6.22 493 KernelVersion: 2.6.22
494 Contact: Pekka Enberg <penberg@cs.helsin 494 Contact: Pekka Enberg <penberg@cs.helsinki.fi>,
495 Christoph Lameter <cl@linux-fou 495 Christoph Lameter <cl@linux-foundation.org>
496 Description: 496 Description:
497 Writing to the validate file c 497 Writing to the validate file causes SLUB to traverse all of its
498 cache's objects and check the 498 cache's objects and check the validity of metadata.
499 499
500 What: /sys/kernel/slab/<cache>/users 500 What: /sys/kernel/slab/<cache>/usersize
501 Date: Jun 2017 501 Date: Jun 2017
502 Contact: David Windsor <dave@nullcore.ne 502 Contact: David Windsor <dave@nullcore.net>
503 Description: 503 Description:
504 The usersize file is read-only 504 The usersize file is read-only and contains the usercopy
505 region size. 505 region size.
506 506
507 What: /sys/kernel/slab/<cache>/slabs 507 What: /sys/kernel/slab/<cache>/slabs_cpu_partial
508 Date: Aug 2011 508 Date: Aug 2011
509 Contact: Christoph Lameter <cl@linux.com 509 Contact: Christoph Lameter <cl@linux.com>
510 Description: 510 Description:
511 This read-only file shows the 511 This read-only file shows the number of partialli allocated
512 frozen slabs. 512 frozen slabs.
513 513
514 What: /sys/kernel/slab/<cache>/cpu_p 514 What: /sys/kernel/slab/<cache>/cpu_partial
515 Date: Aug 2011 515 Date: Aug 2011
516 Contact: Christoph Lameter <cl@linux.com 516 Contact: Christoph Lameter <cl@linux.com>
517 Description: 517 Description:
518 This read-only file shows the 518 This read-only file shows the number of per cpu partial
519 pages to keep around. 519 pages to keep around.
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