Lines Matching +full:line +full:- +full:orders
26 requiring larger clear-page copy-page in page faults which is a
48 Modern kernels support "multi-size THP" (mTHP), which introduces the
50 but smaller than traditional PMD-size (as described above), in
51 increments of a power-of-2 number of pages. mTHP can back anonymous
53 PTE-mapped, but in many cases can still provide similar benefits to
56 prominent because the size of each page isn't as huge as the PMD-sized
66 collapses sequences of basic pages into PMD-sized huge pages.
91 possible to disable hugepages system-wide and to only have them inside
108 -------------------
113 system wide. This can be achieved per-supported-THP-size with one of::
115 echo always >/sys/kernel/mm/transparent_hugepage/hugepages-<size>kB/enabled
116 echo madvise >/sys/kernel/mm/transparent_hugepage/hugepages-<size>kB/enabled
117 echo never >/sys/kernel/mm/transparent_hugepage/hugepages-<size>kB/enabled
125 PMD-sized huge pages unconditionally.
129 echo always >/sys/kernel/mm/transparent_hugepage/hugepages-2048kB/enabled
132 will inherit the top-level "enabled" value::
134 echo inherit >/sys/kernel/mm/transparent_hugepage/hugepages-<size>kB/enabled
138 echo inherit >/sys/kernel/mm/transparent_hugepage/hugepages-2048kB/enabled
140 The top-level setting (for use with "inherit") can be set by issuing
147 By default, PMD-sized hugepages have enabled="inherit" and all other
195 should be self-explanatory. Note that ``madvise(...,
199 By default kernel tries to use huge, PMD-mappable zero page on read
208 PMD-mappable transparent hugepage::
214 "underused". A THP is underused if the number of zero-filled pages in
222 khugepaged will be automatically started when PMD-sized THP is enabled
223 (either of the per-size anon control or the top-level control are set
225 PMD-sized THP is disabled (when both the per-size anon control and the
226 top-level control are "never")
229 --------------------
243 - Global THP controls are set to "always" or "madvise" and
245 - Global THP controls are set to "never" and madvise(..., MADV_COLLAPSE)
252 This will re-enable THPs for the process, as if they were never disabled.
257 This returns a value whose bits indicate how THP-disable is configured:
260 |0|0| 0 No THP-disable behaviour specified.
262 |1|1| 3 THP-except-advised mode is set for this process.
265 -------------------
269 PMD-sized THP and no attempt is made to collapse to other THP
343 You can change the sysfs boot time default for the top-level "enabled"
346 kernel command line.
349 passing ``thp_anon=<size>[KMG],<size>[KMG]:<state>;<size>[KMG]-<size>[KMG]:<state>``,
358 thp_anon=16K-64K:always;128K,512K:inherit;256K:madvise;1M-2M:never
362 not explicitly configured on the command line are implicitly set to
391 sizes not explicitly configured on the command line are implicitly set to
406 to as "multi-size THP" (mTHP). Huge pages of any size are commonly
415 ------------
422 Always try PMD-sized huge pages first, and fall back to smaller-sized
423 huge pages if the PMD-sized huge page allocation fails;
432 Always try PMD-sized huge pages first, and fall back to smaller-sized
433 huge pages if the PMD-sized huge page allocation fails;
445 ``mount -o remount,huge= /mountpoint`` works fine after mount: remounting
457 Force the huge option on for all - very useful for testing;
460 ----------------------
467 '/sys/kernel/mm/transparent_hugepage/hugepages-<size>kB/shmem_enabled'
473 per-size knob is set to 'inherit'.
482 Inherit the top-level "shmem_enabled" value. By default, PMD-sized hugepages
501 transparent_hugepage/hugepages-<size>kB/enabled values and tmpfs mount
509 The number of PMD-sized anonymous transparent huge pages currently used by the
511 To identify what applications are using PMD-sized anonymous transparent huge
514 PMD-sized THP for historical reasons and should have been called
618 In /sys/kernel/mm/transparent_hugepage/hugepages-<size>kB/stats, There are
630 lower orders or small pages.
634 instead falls back to using huge pages with lower orders or
642 is incremented every time a huge page is swapped in from a non-zswap
647 and instead falls back to using huge pages with lower orders or
652 falls back to using huge pages with lower orders or small pages
656 is incremented every time a huge page is swapped out to a non-zswap
679 smaller orders. This can happen for a variety of reasons but a