Changes in Kconfig

62f058287558af11f6d1af3d7597ff8599998b43 - mm/damon: add CONFIG_DAMON_DEBUG_SANITY

Fri, 06 Mar 2026 16:29:04 +0100

mm/damon: add CONFIG_DAMON_DEBUG_SANITYPatch series "mm/damon: add optional debugging-purpose sanity checks".DAMON code has a few assumptions that can be critical if violated. Validating the assumptions in code can be useful at finding such criticalbugs. I was actually adding some such additional sanity checks in mypersonal tree, and those were useful at finding bugs that I made duringthe development of new patches. We also found [1] sometimes theassumptions are misunderstood. The validation can work as gooddocumentation for such cases.Add some of such debugging purpose sanity checks. Because thoseadditional checks can impose more overhead, make those only optional vianew config, CONFIG_DAMON_DEBUG_SANITY, that is recommended for onlydevelopment and test setups. And as recommended, enable it for DAMONkunit tests and selftests.Note that the verification only WARN_ON() for each of the insanity. Thedeveloper or tester may better to set panic_on_oops together, likedamon-tests/corr did [2].This patch (of 10):Add a new build config that will enable additional DAMON sanity checks. It is recommended to be enabled on only development and test setups, sinceit can impose additional overhead.Link: https://lkml.kernel.org/r/20260306152914.86303-1-sj@kernel.orgLink: https://lkml.kernel.org/r/20260306152914.86303-2-sj@kernel.orgLink: https://lore.kernel.org/20251231070029.79682-1-sj@kernel.org [1]Link: https://github.com/damonitor/damon-tests/commit/a80fbee55e272f151b4e5809ee85898aea33e6ff [2]Signed-off-by: SeongJae Park Cc: Brendan Higgins Cc: David Gow Cc: Shuah Khan Signed-off-by: Andrew Morton List of files: /linux/mm/damon/Kconfig

4e915656a38afe8aeebb283493f49c22d675a9fc - mm/damon/Kconfig: make DAMON_STAT_ENABLED_DEFAULT depend on DAMON_STAT

Fri, 15 Aug 2025 11:21:10 +0200

mm/damon/Kconfig: make DAMON_STAT_ENABLED_DEFAULT depend on DAMON_STATThe DAMON_STAT_ENABLED_DEFAULT option is strongly tied to DAMON_STAToption -- enabling it alone is meaningless. This patch makesDAMON_STAT_ENABLED_DEFAULT depend on DAMON_STAT, ensuring functionalconsistency.Link: https://lkml.kernel.org/r/20250815092110.811757-1-lienze@kylinos.cnFixes: 369c415e6073 ("mm/damon: introduce DAMON_STAT module")Signed-off-by: Enze Li Reviewed-by: SeongJae Park Signed-off-by: Andrew Morton List of files: /linux/mm/damon/Kconfig

369c415e60732b7c8ed33368891581246f580d7a - mm/damon: introduce DAMON_STAT module

Wed, 04 Jun 2025 20:31:24 +0200

mm/damon: introduce DAMON_STAT modulePatch series "mm/damon: introduce DAMON_STAT for simple and practicalaccess monitoring", v2.DAMON-based access monitoring is not simple due to required DAMON controland results visualizations. Introduce a static kernel module for makingit simple. The module can be enabled without manual setup and providesaccess pattern metrics that easy to fetch and understand the practicalaccess pattern information, namely estimated memory bandwidth and memoryidle time percentiles.Background and Problems=======================DAMON can be used for monitoring data access patterns of the system andworkloads. Specifically, users can start DAMON to monitor access eventson specific address space with fine controls including address ranges tomonitor and time intervals between samplings and aggregations. Theresulting access information snapshot contains access frequency(nr_accesses) and how long the frequency was kept (age) for each byte.The monitoring usage is not simple and practical enough for productionusage. Users should first start DAMON with a number of parameters, andwait until DAMON's monitoring results capture a reasonable amount of thetime data (age). In production, such manual start and wait is impracticalto capture useful information from a high number of machines in a timelymanner.The monitoring result is also too detailed to be used on productionenvironments. The raw results are hard to be aggregated and/or comparedfor production environments having a large scale of time, space andmachines fleet.Users have to implement and use their own automation of DAMON control andresults processing. It is repetitive and challenging since there is nogood reference or guideline for such automation.Solution: DAMON_STAT====================Implement such automation in kernel space as a static kernel module,namely DAMON_STAT. It can be enabled at build, boot, or run time via itsbuild configuration or module parameter. It monitors the entire physicaladdress space with monitoring intervals that auto-tuned for a reasonableamount of access observations and minimum overhead. It converts the rawmonitoring results into simpler metrics that can easily be aggregated andcompared, namely estimated memory bandwidth and idle time percentiles.Understanding of the metrics and the user interface of DAMON_STAT isessential. Refer to the commit messages of the second and the thirdpatches of this patch series for more details about the metrics. For theuser interface, the standard module parameters system is used. Refer tothe fourth patch of this patch series for details of the user interface.Discussions===========The module aims to be useful on production environments constructed with alarge number of machines that run a long time. The auto-tuned monitoringintervals ensure a reasonable quality of the outputs. The auto-tuningalso ensures its overhead be reasonable and low enough to be enabledalways on the production. The simplified monitoring results metrics canbe useful for showing both coldness (idle time percentiles) and hotness(memory bandwidth) of the system's access pattern. We expect theinformation can be useful for assessing system memory utilization andinspiring optimizations or investigations on both kernel and user spacememory management logics for large scale fleets.We hence expect the module is good enough to be just used in mostenvironments. For special cases that require a custom access monitoringautomation, users will still benefit by using DAMON_STAT as a reference ora guideline for their specialized automation.This patch (of 4):To use DAMON for monitoring access patterns of the system, users shouldmanually start DAMON via DAMON sysfs ABI with a number of parameters forspecifying the monitoring target address space, address ranges, andmonitoring intervals. After that, users should also wait until desiredamount of time data is captured into DAMON's monitoring results. It isbothersome and take a long time to be practical for access monitoring onlarge fleet level production environments.For access-aware system operations use cases like proactive cold memoryreclamation, similar problems existed. We we solved those by introducingdedicated static kernel modules such as DAMON_RECLAIM.Implement such static kernel module for access monitoring, namelyDAMON_STAT. It monitors the entire physical address space with auto-tunedmonitoring intervals. The auto-tuning is set to capture 4 % of observableaccess events in each snapshot while keeping the sampling intervals 5milliseconds in minimum and 10 seconds in maximum. From a few productionenvironments, we confirmed this setup provides high quality monitoringresults with minimum overheads. The module therefore receives only oneuser input, whether to enable or disable it. It can be set on build orboot time via build configuration or kernel boot command line. It canalso be overridden at runtime.Note that this commit only implements the DAMON control part of themodule. Users could get the monitoring results via damon:damon_aggregatedtracepoint, but that's of course not the recommended way. Followingcommits will implement convenient and optimized ways for serving themonitoring results to users.[sj@kernel.org: use IS_ENABLED() for enabled initial value] Link: https://lkml.kernel.org/r/20250604205619.18929-1-sj@kernel.org[sj@kernel.org: reset enabled when DAMON start failed] Link: https://lkml.kernel.org/r/20250706184750.36588-1-sj@kernel.orgLink: https://lkml.kernel.org/r/20250604183127.13968-1-sj@kernel.orgLink: https://lkml.kernel.org/r/20250604183127.13968-2-sj@kernel.orgSigned-off-by: SeongJae Park Cc: Jonathan Corbet Signed-off-by: Andrew Morton List of files: /linux/mm/damon/Kconfig

aef17cb3d3c43854002956f24c24ec8e1a0e3546 - Revert "mm/damon/Kconfig: enable CONFIG_DAMON by default"

Tue, 10 Jun 2025 19:22:15 +0200

Revert "mm/damon/Kconfig: enable CONFIG_DAMON by default"This reverts commit 28615e6eed152f2fda5486680090b74aeed7b554.No, we don't make random features default to being on.Reported-by: Geert Uytterhoeven Cc: Andrew Morton Cc: SeongJae Park Signed-off-by: Linus Torvalds List of files: /linux/mm/damon/Kconfig

28615e6eed152f2fda5486680090b74aeed7b554 - mm/damon/Kconfig: enable CONFIG_DAMON by default

Wed, 21 May 2025 06:27:55 +0200

mm/damon/Kconfig: enable CONFIG_DAMON by defaultAs of this writing, multiple major distros including Alma, Amazon,Android, CentOS, Debian, Fedora, and Oracle are build-enabling DAMON (setCONFIG_DAMON[1]). Enabling it by default will save configuration setuptime for the current and future DAMON users.Build-enabling DAMON does not introduce a real risk since it makes nobehavioral change by default. It requires explicit user requests to doanything. Only one potential risk is making the size of the kernel alittle bit larger. On a production-purpose configuration, it increasesthe resulting kernel package size by about 0.1 % of the final packagefile. I believe that's too small to be a real problem in common setups.Hence, the benefit of enabling CONFIG_DAMON outweighs the potential risk. Set CONFIG_DAMON by default.Link: https://oracle.github.io/kconfigs/?config=UTS_RELEASE&config=DAMON [1]Link: https://lkml.kernel.org/r/20250521042755.39653-3-sj@kernel.orgSigned-off-by: SeongJae Park Acked-by: Honggyu Kim Signed-off-by: Andrew Morton List of files: /linux/mm/damon/Kconfig

0acfc656df50403cbd9dcb2d7b2a04fce161e6e4 - mm/damon/Kconfig: set DAMON_{VADDR,PADDR,SYSFS} default to DAMON

Wed, 21 May 2025 06:27:54 +0200

mm/damon/Kconfig: set DAMON_{VADDR,PADDR,SYSFS} default to DAMONPatch series "mm/damon: build-enable essential DAMON components bydefault".As of this writing, multiple major distros including Alma, Amazon,Android, CentOS, Debian, Fedora, and Oracle are build-enabling DAMON (setCONFIG_DAMON[1]). Configuring DAMON is not very easy, since it isdisabled by default, and there are multiple essential options that need tobe manually turned on, one by one. Make it easier, by grouping essentialconfigurations to be enabled with one selection, and enabling build of theessential parts of DAMON by default.Note that build-enabling DAMON does not introduce any real risk, since itmakes no behavioral change by default. It requires explicit user requeststo do anything. Only one potential risk is making the size of the kernela little bit larger. On a production-purpose configuration, it increasesthe resulting kernel package binary size by about 0.1 % of the finalpackage file. I believe that's too small to be a real problem in commonsetups.DAMON_{VADDR,PADDR,SYSFS} are de-facto essential parts of DAMON for normalusages. Because those need to be enabled one by one, however, and thereare other test-purpose or non-essential configurations, it is easy to beconfused and make mistakes at setup. Make the essential configurationsdefault to CONFIG_DAMON, so that those can be enabled by default with asingle change.Link: https://oracle.github.io/kconfigs/?config=UTS_RELEASE&config=DAMON [1]Link: https://lkml.kernel.org/r/20250521042755.39653-1-sj@kernel.orgLink: https://lkml.kernel.org/r/20250521042755.39653-2-sj@kernel.orgSigned-off-by: SeongJae Park Acked-by: Honggyu Kim Signed-off-by: Andrew Morton List of files: /linux/mm/damon/Kconfig

5ec4333b1967cab7607bd9e863b47a81eb30b250 - mm/damon: remove DAMON debugfs interface

Mon, 06 Jan 2025 20:19:41 +0100

mm/damon: remove DAMON debugfs interfaceIt's time to remove DAMON debugfs interface, which has deprecated longbefore in February 2023. Read the cover letter of this patch series formore details.All documents and related tests are also removed. Finally remove theinterface.Link: https://lkml.kernel.org/r/20250106191941.107070-9-sj@kernel.orgSigned-off-by: SeongJae Park Cc: Alex Shi Cc: Brendan Higgins Cc: David Gow Cc: Hu Haowen <2023002089@link.tyut.edu.cn>Cc: Jonathan Corbet Cc: Rae Moar Cc: Shuah Khan Cc: Yanteng Si Signed-off-by: Andrew Morton List of files: /linux/mm/damon/Kconfig

4d047d4f8ab4bbbd0b017fb287fcdad083e081ea - mm/damon: remove DAMON debugfs interface kunit tests

Mon, 06 Jan 2025 20:19:40 +0100

mm/damon: remove DAMON debugfs interface kunit testsIt's time to remove DAMON debugfs interface, which has deprecated longbefore in February 2023. Read the cover letter of this patch series formore details.Remove kunit tests for the interface, to prevent unnecessary testfailures.Link: https://lkml.kernel.org/r/20250106191941.107070-8-sj@kernel.orgSigned-off-by: SeongJae Park Cc: Alex Shi Cc: Brendan Higgins Cc: David Gow Cc: Hu Haowen <2023002089@link.tyut.edu.cn>Cc: Jonathan Corbet Cc: Rae Moar Cc: Shuah Khan Cc: Yanteng Si Signed-off-by: Andrew Morton List of files: /linux/mm/damon/Kconfig

12d021659c7aa5059835e671e57c4a163a64d2e9 - mm/damon/Kconfig: update DBGFS_KUNIT prompt copy for SYSFS_KUNIT

Tue, 29 Oct 2024 00:30:57 +0100

mm/damon/Kconfig: update DBGFS_KUNIT prompt copy for SYSFS_KUNITCONFIG_DAMON_SYSFS_KUNIT_TEST prompt is copied from that for DAMON debugfsinterface kunit tests, and not correctly updated. Fix it.Link: https://lkml.kernel.org/r/20241028233058.283381-6-sj@kernel.orgFixes: b8ee5575f763 ("mm/damon/sysfs-test: add a unit test for damon_sysfs_set_targets()")Signed-off-by: SeongJae Park Cc: Andrew Paniakin Cc: Brendan Higgins Cc: David Gow Cc: Shuah Khan Signed-off-by: Andrew Morton List of files: /linux/mm/damon/Kconfig

6901cf55de224b2ca51a5675b86c8ef241ae640c - mm/damon/Kconfig: update DAMON doc URL

Tue, 24 Sep 2024 10:21:46 +0200

mm/damon/Kconfig: update DAMON doc URLThe old URL doesn't really work anymore and as the documentation has beenintegrated in the main kernel documentation site, change the URL to pointto that.Link: https://lkml.kernel.org/r/20240924082331.11499-1-didi.debian@cknow.orgSigned-off-by: Diederik de Haas Reviewed-by: SeongJae Park Signed-off-by: Andrew Morton List of files: /linux/mm/damon/Kconfig

f4cba4bf6777b15d934a354e8aa07059112bf2e8 - mm/damon: rename CONFIG_DAMON_DBGFS to DAMON_DBGFS_DEPRECATED

Tue, 30 Jan 2024 02:35:41 +0100

mm/damon: rename CONFIG_DAMON_DBGFS to DAMON_DBGFS_DEPRECATEDDAMON debugfs interface is deprecated. The fact has documented by commit5445fcbc4cda ("Docs/admin-guide/mm/damon/usage: add DAMON debugfsinterface deprecation notice"). Commit 620932cd2852 ("mm/damon/dbgfs:print DAMON debugfs interface deprecation message") further startedprinting a warning message when users still use it. Many people don'tread documentation or kernel log, though.Make the deprecation harder to be ignored using the approach of commiteb07c4f39c3e ("mm/slab: rename CONFIG_SLAB to CONFIG_SLAB_DEPRECATED"). 'make oldconfig' with 'CONFIG_DAMON_DBGFS=y' will get a new prompt withthe explicit deprecation notice on the name. 'make olddefconfig' with'CONFIG_DAMON_DBGFS=y' will result in not building DAMON debugfsinterface. If there is a real user of DAMON debugfs interface, they willcomplain the change to the builder.Link: https://lkml.kernel.org/r/20240130013549.89538-3-sj@kernel.orgSigned-off-by: SeongJae Park Cc: Alex Shi Cc: Hu Haowen <2023002089@link.tyut.edu.cn>Cc: Jonathan Corbet Cc: Shuah Khan Cc: Yanteng Si Signed-off-by: Andrew Morton List of files: /linux/mm/damon/Kconfig

b8ee5575f763c239902f8523d82103a45c153b29 - mm/damon/sysfs-test: add a unit test for damon_sysfs_set_targets()

Sun, 22 Oct 2023 23:07:34 +0200

mm/damon/sysfs-test: add a unit test for damon_sysfs_set_targets()damon_sysfs_set_targets() had a bug that can result in unexpected memoryusage and monitoring overhead increase. The bug has fixed by a previouscommit. Add a unit test for avoiding a similar bug of future.Link: https://lkml.kernel.org/r/20231022210735.46409-3-sj@kernel.orgSigned-off-by: SeongJae Park Cc: Brendan Higgins Signed-off-by: Andrew Morton List of files: /linux/mm/damon/Kconfig

61e88a2f66580d7488bbf7454423c81886d2e8cd - mm/damon/Kconfig: add DAMON debugfs interface deprecation notice

Thu, 09 Feb 2023 20:20:08 +0100

mm/damon/Kconfig: add DAMON debugfs interface deprecation noticeDAMON debugfs interface has announced to be deprecated after >v5.15 LTSkernel is released. And, v6.1.y has announced to be an LTS[1].Though the announcement was there for a while, some people might notnoticed that so far. Also, some users could depend on it and haveproblems at movng to the alternative (DAMON sysfs interface).For such cases, note DAMON debugfs interface as deprecated, and contactsto ask helps on the Kconfig.[1] https://git.kernel.org/pub/scm/docs/kernel/website.git/commit/?id=332e9121320bc7461b2d3a79665caf153e51732cLink: https://lkml.kernel.org/r/20230209192009.7885-3-sj@kernel.orgSigned-off-by: SeongJae Park Cc: Jonathan Corbet Signed-off-by: Andrew Morton List of files: /linux/mm/damon/Kconfig

e8600ce2d2e6ad1df4d0717beb362ee4cd39aaa3 - mm/damon/Kconfig: notify debugfs deprecation plan

Fri, 09 Sep 2022 22:28:59 +0200

mm/damon/Kconfig: notify debugfs deprecation planCommit b18402726bd1 ("Docs/admin-guide/mm/damon/usage: document DAMONsysfs interface") announced the DAMON debugfs interface deprecation plan,but it is not so aggressively announced. As the deprecation time iscoming, this commit makes the announce more easy to be found by adding thenote to the config menu of DAMON debugfs interface.Link: https://lkml.kernel.org/r/20220909202901.57977-6-sj@kernel.orgSigned-off-by: SeongJae Park Cc: Brendan Higgins Cc: Jonathan Corbet Cc: Shuah Khan Cc: Yun Levi Signed-off-by: Andrew Morton List of files: /linux/mm/damon/Kconfig

40e983cca9274e177bd5b9379299b44d9536ac68 - mm/damon: introduce DAMON-based LRU-lists Sorting

Mon, 13 Jun 2022 21:23:00 +0200

mm/damon: introduce DAMON-based LRU-lists SortingUsers can do data access-aware LRU-lists sorting using 'LRU_PRIO' and'LRU_DEPRIO' DAMOS actions. However, finding best parameters includingthe hotness/coldness thresholds, CPU quota, and watermarks could bechallenging for some users. To make the scheme easy to be used withoutcomplex tuning for common situations, this commit implements a statickernel module called 'DAMON_LRU_SORT' using the 'LRU_PRIO' and'LRU_DEPRIO' DAMOS actions.It proactively sorts LRU-lists using DAMON with conservatively chosendefault values of the parameters. That is, the module under its defaultparameters will make no harm for common situations but provide some levelof efficiency improvements for systems having clear hot/cold accesspattern under a level of memory pressure while consuming only a limitedsmall portion of CPU time.Link: https://lkml.kernel.org/r/20220613192301.8817-9-sj@kernel.orgSigned-off-by: SeongJae Park Cc: Jonathan Corbet Signed-off-by: Andrew Morton List of files: /linux/mm/damon/Kconfig

c951cd3b89010c7a4751b9d4ea074007e44851e6 - mm/damon: implement a minimal stub for sysfs-based DAMON interface

Tue, 22 Mar 2022 22:49:27 +0100

mm/damon: implement a minimal stub for sysfs-based DAMON interfaceDAMON's debugfs-based user interface served very well, so far. However,it unnecessarily depends on debugfs, while DAMON is not aimed to be usedfor only debugging. Also, the interface receives multiple values via onefile. For example, schemes file receives 18 values separated by whitespaces. As a result, it is ineffient, hard to be used, and difficult tobe extended. Especially, keeping backward compatibility of user spacetools is getting only challenging. It would be better to implementanother reliable and flexible interface and deprecate the debugfsinterface in long term.To this end, this commit implements a stub of a part of the new userinterface of DAMON using sysfs. Specifically, this commit implements thesysfs control parts for virtual address space monitoring.More specifically, the idea of the new interface is, using directoryhierarchies and making one file for one value. The hierarchy that thiscommit is introducing is as below. In the below figure, parents-childrenrelations are represented with indentations, each directory is having``/`` suffix, and files in each directory are separated by comma (","). /sys/kernel/mm/damon/admin │ kdamonds/nr_kdamonds │ │ 0/state,pid │ │ │ contexts/nr_contexts │ │ │ │ 0/operations │ │ │ │ │ monitoring_attrs/ │ │ │ │ │ │ intervals/sample_us,aggr_us,update_us │ │ │ │ │ │ nr_regions/min,max │ │ │ │ │ targets/nr_targets │ │ │ │ │ │ 0/pid_target │ │ │ │ │ │ ... │ │ │ │ ... │ │ ...Writing a number to each 'nr' file makes directories of name <0> to in the directory of the 'nr' file. That's all this commit does.Writing proper values to relevant files will construct the DAMON contexts,and writing a special keyword, 'on', to 'state' files for each kdamondwill ask DAMON to start the constructed contexts.For a short example, using below commands for monitoring virtual addressspaces of a given workload is imaginable: # cd /sys/kernel/mm/damon/admin/ # echo 1 > kdamonds/nr_kdamonds # echo 1 > kdamonds/0/contexts/nr_contexts # echo vaddr > kdamonds/0/contexts/0/operations # echo 1 > kdamonds/0/contexts/0/targets/nr_targets # echo $(pidof ) > kdamonds/0/contexts/0/targets/0/pid_target # echo on > kdamonds/0/statePlease note that this commit is implementing only the sysfs part stub asabovely mentioned. This commit doesn't implement the special keywords for'state' files. Following commits will do that.[jiapeng.chong@linux.alibaba.com: fix missing error code in damon_sysfs_attrs_add_dirs()] Link: https://lkml.kernel.org/r/20220302111120.24984-1-jiapeng.chong@linux.alibaba.comLink: https://lkml.kernel.org/r/20220228081314.5770-4-sj@kernel.orgSigned-off-by: SeongJae Park Signed-off-by: Jiapeng Chong Cc: David Rientjes Cc: Greg Kroah-Hartman Cc: Jonathan Corbet Cc: Shuah Khan Cc: Xin Hao Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds List of files: /linux/mm/damon/Kconfig

f7d911c39cbbb88d625216a0cfd0517a3047c46e - mm/damon: rename damon_primitives to damon_operations

Tue, 22 Mar 2022 22:48:46 +0100

mm/damon: rename damon_primitives to damon_operationsPatch series "Allow DAMON user code independent of monitoring primitives".In-kernel DAMON user code is required to configure the monitoring context(struct damon_ctx) with proper monitoring primitives (structdamon_primitive). This makes the user code dependent to all supportingmonitoring primitives. For example, DAMON debugfs interface depends onboth DAMON_VADDR and DAMON_PADDR, though some users have interest in onlyone use case. As more monitoring primitives are introduced, the problemwill be bigger.To minimize such unnecessary dependency, this patchset makes monitoringprimitives can be registered by the implemnting code and later dynamicallysearched and selected by the user code.In addition to that, this patchset renames monitoring primitives tomonitoring operations, which is more easy to intuitively understand whatit means and how it would be structed.This patch (of 8):DAMON has a set of callback functions called monitoring primitives and letit can be configured with various implementations for easy extension fordifferent address spaces and usages. However, the word 'primitive' is notso explicit. Meanwhile, many other structs resembles similar purposecalls themselves 'operations'. To make the code easier to be understood,this commit renames 'damon_primitives' to 'damon_operations' before it istoo late to rename.Link: https://lkml.kernel.org/r/20220215184603.1479-1-sj@kernel.orgLink: https://lkml.kernel.org/r/20220215184603.1479-2-sj@kernel.orgSigned-off-by: SeongJae Park Cc: Xin Hao Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds List of files: /linux/mm/damon/Kconfig

43b0536cb4710e7bb591edfda7e68a1c327a3409 - mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM)

Fri, 05 Nov 2021 21:47:57 +0100

mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM)This implements a new kernel subsystem that finds cold memory regionsusing DAMON and reclaims those immediately. It is intended to be usedas proactive lightweigh reclamation logic for light memory pressure.For heavy memory pressure, it could be inactivated and fall back to thetraditional page-scanning based reclamation.It's implemented on top of DAMON framework to use the DAMON-basedOperation Schemes (DAMOS) feature. It utilizes all the DAMOS featuresincluding speed limit, prioritization, and watermarks.It could be enabled and tuned in boot time via the kernel bootparameter, and in run time via its module parameters('/sys/module/damon_reclaim/parameters/') interface.[yangyingliang@huawei.com: fix error return code in damon_reclaim_turn()] Link: https://lkml.kernel.org/r/20211025124500.2758060-1-yangyingliang@huawei.comLink: https://lkml.kernel.org/r/20211019150731.16699-15-sj@kernel.orgSigned-off-by: SeongJae Park Signed-off-by: Yang Yingliang Cc: Amit Shah Cc: Benjamin Herrenschmidt Cc: David Hildenbrand Cc: David Rientjes Cc: David Woodhouse Cc: Greg Thelen Cc: Jonathan Cameron Cc: Jonathan Corbet Cc: Leonard Foerster Cc: Marco Elver Cc: Markus Boehme Cc: Shakeel Butt Cc: Shuah Khan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds List of files: /linux/mm/damon/Kconfig

c026291ab88f02247999959d01182cb8eb6e6a5b - mm/damon/dbgfs: support physical memory monitoring

Fri, 05 Nov 2021 21:47:00 +0100

mm/damon/dbgfs: support physical memory monitoringThis makes the 'damon-dbgfs' to support the physical memory monitoring,in addition to the virtual memory monitoring.Users can do the physical memory monitoring by writing a specialkeyword, 'paddr' to the 'target_ids' debugfs file. Then, DAMON willcheck the special keyword and configure the monitoring context to runwith the primitives for the physical address space.Unlike the virtual memory monitoring, the monitoring target region willnot be automatically set. Therefore, users should also set themonitoring target address region using the 'init_regions' debugfs file.Also, note that the physical memory monitoring will not automaticallyterminated. The user should explicitly turn off the monitoring bywriting 'off' to the 'monitor_on' debugfs file.Link: https://lkml.kernel.org/r/20211012205711.29216-7-sj@kernel.orgSigned-off-by: SeongJae Park Cc: Amit Shah Cc: Benjamin Herrenschmidt Cc: Brendan Higgins Cc: David Hildenbrand Cc: David Rienjes Cc: David Woodhouse Cc: Greg Thelen Cc: Jonathan Cameron Cc: Jonathan Corbet Cc: Leonard Foerster Cc: Marco Elver Cc: Markus Boehme Cc: Shakeel Butt Cc: Shuah Khan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds List of files: /linux/mm/damon/Kconfig

a28397beb55b68bd0f15c6778540e8ae1bc26d21 - mm/damon: implement primitives for physical address space monitoring

Fri, 05 Nov 2021 21:46:56 +0100

mm/damon: implement primitives for physical address space monitoringThis implements the monitoring primitives for the physical memoryaddress space. Internally, it uses the PTE Accessed bit, similar tothat of the virtual address spaces monitoring primitives. It supportsonly user memory pages, as idle pages tracking does. If the monitoringtarget physical memory address range contains non-user memory pages,access check of the pages will do nothing but simply treat the pages asnot accessed.Link: https://lkml.kernel.org/r/20211012205711.29216-6-sj@kernel.orgSigned-off-by: SeongJae Park Cc: Amit Shah Cc: Benjamin Herrenschmidt Cc: Brendan Higgins Cc: David Hildenbrand Cc: David Rienjes Cc: David Woodhouse Cc: Greg Thelen Cc: Jonathan Cameron Cc: Jonathan Corbet Cc: Leonard Foerster Cc: Marco Elver Cc: Markus Boehme Cc: Shakeel Butt Cc: Shuah Khan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds List of files: /linux/mm/damon/Kconfig