Lines Matching +full:idle +full:- +full:state +full:- +full:name
2 zram: Compressed RAM-based block devices
8 The zram module creates RAM-based block devices named /dev/zram<id>
20 There are several ways to configure and manage zram device(-s):
23 b) using zramctl utility, provided by util-linux (util-linux@vger.kernel.org).
28 In order to get a better idea about zramctl please consult util-linux
29 documentation, zramctl man-page or `zramctl --help`. Please be informed
30 that zram maintainers do not develop/maintain util-linux or zramctl, should
31 you have any questions please contact util-linux@vger.kernel.org
45 -EBUSY an attempt to modify an attribute that cannot be changed once
47 -ENOMEM zram was not able to allocate enough memory to fulfil your
49 -EINVAL invalid input has been provided.
50 -EAGAIN re-try operation later (e.g. when attempting to run recompress
58 if [ $? -ne 0 ]; then
74 pre-created. Default: 1.
80 allocate multiple compression streams - one per online CPU - thus
83 become offline. There is no single-compression-stream mode anymore,
115 attribute which provides a per-algorithm params configuration.
118 In addition, certain compression algorithms support pre-trained dictionaries,
120 compression algorithm to use external pre-trained dictionary, pass full
123 #pass path to pre-trained zstd dictionary
130 #pass path to pre-trained zstd dictionary and compression level
134 Parameters are algorithm specific: not all algorithms support pre-trained
194 zram provides a control interface, which enables dynamic (on-demand) device
203 cat /sys/class/zram-control/hot_add
209 echo X > /sys/class/zram-control/hot_remove
214 Per-device statistics are exported as various nodes under /sys/block/zram<id>/
217 please read Documentation/ABI/testing/sysfs-block-zram.
220 Name access description
223 initstate RO shows the initialization state of the device
238 idle WO mark allocated slot as idle
259 invalid_io The number of non-page-size-aligned I/O requests
337 ---------
339 With CONFIG_ZRAM_WRITEBACK, zram can write idle/incompressible page
350 To use idle page writeback, first, user need to declare zram pages
351 as idle::
353 echo all > /sys/block/zramX/idle
355 From now on, any pages on zram are idle pages. The idle mark
357 IOW, unless there is access request, those pages are still idle pages.
359 marked as idle based on how long (in seconds) it's been since they were
362 echo 86400 > /sys/block/zramX/idle
365 seconds (one day) will be marked idle.
367 Admin can request writeback of those idle pages at right timing via::
369 echo idle > /sys/block/zramX/writeback
371 With the command, zram will writeback idle pages from memory to the storage.
373 Additionally, if a user choose to writeback only huge and idle pages
405 If admin wants to limit writeback as per-day 400M, they could do it
437 -------------
444 that default algorithm failed to compress). Another application is idle pages
445 recompression - pages that are cold and sit in the memory can be recompressed
457 #1: lzo lzo-rle lz4 lz4hc [zstd]
458 #2: lzo lzo-rle lz4 [lz4hc] zstd
477 #IDLE pages recompression is activated by `idle` mode
478 echo "type=idle" > /sys/block/zramX/recompress
486 The number of idle pages can be significant, so user-space can pass a size
493 #recompress idle pages larger than 2000 bytes
494 echo "type=idle threshold=2000" > /sys/block/zramX/recompress
496 It is also possible to limit the number of pages zram re-compression will
501 Recompression of idle pages requires memory tracking.
503 During re-compression for every page, that matches re-compression criteria,
505 order of their priorities. ZRAM stops either when re-compression was
506 successful (re-compressed object is smaller in size than the original one)
507 and matches re-compression criteria (e.g. size threshold) or when there are
509 successfully re-compressed the page such a page is marked as incompressible,
510 so ZRAM will not attempt to re-compress it in the future.
512 This re-compression behaviour, when it iterates through the list of
532 If you enable the feature, you could see block state via
546 state of the block:
555 idle page
562 and the block's state is huge so it is written back to the backing