- 23 Mar, 2022 1 commit
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git://git.infradead.org/users/willy/pagecacheLinus Torvalds authored
Pull folio updates from Matthew Wilcox: - Rewrite how munlock works to massively reduce the contention on i_mmap_rwsem (Hugh Dickins): https://lore.kernel.org/linux-mm/8e4356d-9622-a7f0-b2c-f116b5f2efea@google.com/ - Sort out the page refcount mess for ZONE_DEVICE pages (Christoph Hellwig): https://lore.kernel.org/linux-mm/20220210072828.2930359-1-hch@lst.de/ - Convert GUP to use folios and make pincount available for order-1 pages. (Matthew Wilcox) - Convert a few more truncation functions to use folios (Matthew Wilcox) - Convert page_vma_mapped_walk to use PFNs instead of pages (Matthew Wilcox) - Convert rmap_walk to use folios (Matthew Wilcox) - Convert most of shrink_page_list() to use a folio (Matthew Wilcox) - Add support for creating large folios in readahead (Matthew Wilcox) * tag 'folio-5.18c' of git://git.infradead.org/users/willy/pagecache: (114 commits) mm/damon: minor cleanup for damon_pa_young selftests/vm/transhuge-stress: Support file-backed PMD folios mm/filemap: Support VM_HUGEPAGE for file mappings mm/readahead: Switch to page_cache_ra_order mm/readahead: Align file mappings for non-DAX mm/readahead: Add large folio readahead mm: Support arbitrary THP sizes mm: Make large folios depend on THP mm: Fix READ_ONLY_THP warning mm/filemap: Allow large folios to be added to the page cache mm: Turn can_split_huge_page() into can_split_folio() mm/vmscan: Convert pageout() to take a folio mm/vmscan: Turn page_check_references() into folio_check_references() mm/vmscan: Account large folios correctly mm/vmscan: Optimise shrink_page_list for non-PMD-sized folios mm/vmscan: Free non-shmem folios without splitting them mm/rmap: Constify the rmap_walk_control argument mm/rmap: Convert rmap_walk() to take a folio mm: Turn page_anon_vma() into folio_anon_vma() mm/rmap: Turn page_lock_anon_vma_read() into folio_lock_anon_vma_read() ...
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- 22 Mar, 2022 39 commits
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Linus Torvalds authored
Merge updates from Andrew Morton: - A few misc subsystems: kthread, scripts, ntfs, ocfs2, block, and vfs - Most the MM patches which precede the patches in Willy's tree: kasan, pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap, sparsemem, vmalloc, pagealloc, memory-failure, mlock, hugetlb, userfaultfd, vmscan, compaction, mempolicy, oom-kill, migration, thp, cma, autonuma, psi, ksm, page-poison, madvise, memory-hotplug, rmap, zswap, uaccess, ioremap, highmem, cleanups, kfence, hmm, and damon. * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (227 commits) mm/damon/sysfs: remove repeat container_of() in damon_sysfs_kdamond_release() Docs/ABI/testing: add DAMON sysfs interface ABI document Docs/admin-guide/mm/damon/usage: document DAMON sysfs interface selftests/damon: add a test for DAMON sysfs interface mm/damon/sysfs: support DAMOS stats mm/damon/sysfs: support DAMOS watermarks mm/damon/sysfs: support schemes prioritization mm/damon/sysfs: support DAMOS quotas mm/damon/sysfs: support DAMON-based Operation Schemes mm/damon/sysfs: support the physical address space monitoring mm/damon/sysfs: link DAMON for virtual address spaces monitoring mm/damon: implement a minimal stub for sysfs-based DAMON interface mm/damon/core: add number of each enum type values mm/damon/core: allow non-exclusive DAMON start/stop Docs/damon: update outdated term 'regions update interval' Docs/vm/damon/design: update DAMON-Idle Page Tracking interference handling Docs/vm/damon: call low level monitoring primitives the operations mm/damon: remove unnecessary CONFIG_DAMON option mm/damon/paddr,vaddr: remove damon_{p,v}a_{target_valid,set_operations}() mm/damon/dbgfs-test: fix is_target_id() change ... -
Xin Hao authored
In damon_sysfs_kdamond_release(), we have use container_of() to get "kdamond" pointer, so there no need to get it once again. Link: https://lkml.kernel.org/r/20220303075314.22502-1-xhao@linux.alibaba.comSigned-off-by:
Xin Hao <xhao@linux.alibaba.com> Reviewed-by:
SeongJae Park <sj@kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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SeongJae Park authored
This commit adds DAMON sysfs interface ABI document under Documentation/ABI/testing. Link: https://lkml.kernel.org/r/20220228081314.5770-14-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
This commit adds detailed usage of DAMON sysfs interface in the admin-guide document for DAMON. Link: https://lkml.kernel.org/r/20220228081314.5770-13-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
This commit adds a selftest for DAMON sysfs interface. It tests the functionality of 'nr' files and existence of files in each directory of the hierarchy. Link: https://lkml.kernel.org/r/20220228081314.5770-12-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
This commit makes DAMON sysfs interface supports the DAMOS stats feature. Specifically, this commit adds 'stats' directory under each scheme directory, and update the contents of the files under the directory according to the latest monitoring results, when the user writes special keyword, 'update_schemes_stats' to the 'state' file of the kdamond. As a result, the files hierarchy becomes as below: /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 │ │ │ │ │ │ │ regions/nr_regions │ │ │ │ │ │ │ │ 0/start,end │ │ │ │ │ │ │ │ ... │ │ │ │ │ │ ... │ │ │ │ │ schemes/nr_schemes │ │ │ │ │ │ 0/action │ │ │ │ │ │ │ access_pattern/ │ │ │ │ │ │ │ │ sz/min,max │ │ │ │ │ │ │ │ nr_accesses/min,max │ │ │ │ │ │ │ │ age/min,max │ │ │ │ │ │ │ quotas/ms,sz,reset_interval_ms │ │ │ │ │ │ │ │ weights/sz_permil,nr_accesses_permil,age_permil │ │ │ │ │ │ │ watermarks/metric,interval_us,high,mid,low │ │ │ │ │ │ │ stats/ <- NEW DIRECTORY │ │ │ │ │ │ │ │ nr_tried,sz_tried,nr_applied,sz_applied,qt_exceeds │ │ │ │ │ │ ... │ │ │ │ ... │ │ ... Link: https://lkml.kernel.org/r/20220228081314.5770-11-sj@kernel.orgSigned-off-by: -
SeongJae Park authored
This commit makes DAMON sysfs interface supports the DAMOS watermarks feature. Specifically, this commit adds 'watermarks' directory under each scheme directory and makes kdamond 'state' file writing respects the contents in the directory. As a result, the files hierarchy becomes as below: /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 │ │ │ │ │ │ │ regions/nr_regions │ │ │ │ │ │ │ │ 0/start,end │ │ │ │ │ │ │ │ ... │ │ │ │ │ │ ... │ │ │ │ │ schemes/nr_schemes │ │ │ │ │ │ 0/action │ │ │ │ │ │ │ access_pattern/ │ │ │ │ │ │ │ │ sz/min,max │ │ │ │ │ │ │ │ nr_accesses/min,max │ │ │ │ │ │ │ │ age/min,max │ │ │ │ │ │ │ quotas/ms,sz,reset_interval_ms │ │ │ │ │ │ │ │ weights/sz_permil,nr_accesses_permil,age_permil │ │ │ │ │ │ │ watermarks/ <- NEW DIRECTORY │ │ │ │ │ │ │ │ metric,interval_us,high,mid,lo │ │ │ │ │ │ ... │ │ │ │ ... │ │ ... [sj@kernel.org: fix out-of-bound array access for wmark_metric_strs[]] Link: https://lkml.kernel.org/r/20220301185619.2904-1-sj@kernel.org Link: https://lkml.kernel.org/r/20220228081314.5770-10-sj@kernel.orgSigned-off-by: -
SeongJae Park authored
This commit makes DAMON sysfs interface supports the DAMOS' regions prioritization weights feature under quotas limitation. Specifically, this commit adds 'weights' directory under each scheme directory and makes kdamond 'state' file writing respects the contents in the directory. /sys/kernel/mm/damon/admin │ kdamonds/nr │ │ 0/state,pid │ │ │ contexts/nr │ │ │ │ 0/operations │ │ │ │ │ monitoring_attrs/intervals/sample_us,aggr_us,update_us │ │ │ │ │ │ nr_regions/min,max │ │ │ │ │ targets/nr │ │ │ │ │ │ 0/pid │ │ │ │ │ │ │ regions/nr │ │ │ │ │ │ │ │ 0/start,end │ │ │ │ │ │ │ │ ... │ │ │ │ │ │ ... │ │ │ │ │ schemes/nr │ │ │ │ │ │ 0/action │ │ │ │ │ │ │ access_pattern/ │ │ │ │ │ │ │ │ sz/min,max │ │ │ │ │ │ │ │ nr_accesses/min,max │ │ │ │ │ │ │ │ age/min,max │ │ │ │ │ │ │ quotas/ms,bytes,reset_interval_ms │ │ │ │ │ │ │ │ weights/ <- NEW DIRECTORY │ │ │ │ │ │ │ │ │ weights/sz_permil,nr_accesses_permil,age_permil │ │ │ │ │ │ ... │ │ │ │ ... │ │ ... Link: https://lkml.kernel.org/r/20220228081314.5770-9-sj@kernel.orgSigned-off-by: -
SeongJae Park authored
This commit makes DAMON sysfs interface supports the DAMOS quotas feature. Specifically, this commit adds 'quotas' directory under each scheme directory and makes kdamond 'state' file writing respects the contents in the directory. As a result, the files hierarchy becomes as below: /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 │ │ │ │ │ │ │ regions/nr_regions │ │ │ │ │ │ │ │ 0/start,end │ │ │ │ │ │ │ │ ... │ │ │ │ │ │ ... │ │ │ │ │ schemes/nr_schemes │ │ │ │ │ │ 0/action │ │ │ │ │ │ │ access_pattern/ │ │ │ │ │ │ │ │ sz/min,max │ │ │ │ │ │ │ │ nr_accesses/min,max │ │ │ │ │ │ │ │ age/min,max │ │ │ │ │ │ │ quotas/ms,bytes,reset_interval_ms <- NEW DIRECTORY │ │ │ │ │ │ ... │ │ │ │ ... │ │ ... Link: https://lkml.kernel.org/r/20220228081314.5770-8-sj@kernel.orgSigned-off-by: -
SeongJae Park authored
This commit makes DAMON sysfs interface supports the DAMON-based operation schemes (DAMOS) feature. Specifically, this commit adds 'schemes' directory under each context direcotry, and makes kdamond 'state' file writing respects the contents in the directory. Note that this commit doesn't support all features of DAMOS but only the target access pattern and action feature. Supports for quotas, prioritization, watermarks will follow. As a result, the files hierarchy becomes as below: /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 │ │ │ │ │ │ │ regions/nr_regions │ │ │ │ │ │ │ │ 0/start,end │ │ │ │ │ │ │ │ ... │ │ │ │ │ │ ... │ │ │ │ │ schemes/nr_schemes <- NEW DIRECTORY │ │ │ │ │ │ 0/action │ │ │ │ │ │ │ access_pattern/ │ │ │ │ │ │ │ │ sz/min,max │ │ │ │ │ │ │ │ nr_accesses/min,max │ │ │ │ │ │ │ │ age/min,max │ │ │ │ │ │ ... │ │ │ │ ... │ │ ... Link: https://lkml.kernel.org/r/20220228081314.5770-7-sj@kernel.orgSigned-off-by: -
SeongJae Park authored
This commit makes DAMON sysfs interface supports the physical address space monitoring. Specifically, this commit adds support of the initial monitoring regions set feature by adding 'regions' directory under each target directory and makes context operations file to receive 'paddr' in addition to 'vaddr'. As a result, the files hierarchy becomes as below: /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 │ │ │ │ │ │ │ regions/nr_regions <- NEW DIRECTORY │ │ │ │ │ │ │ │ 0/start,end │ │ │ │ │ │ │ │ ... │ │ │ │ │ │ ... │ │ │ │ ... │ │ ... Link: https://lkml.kernel.org/r/20220228081314.5770-6-sj@kernel.orgSigned-off-by: -
SeongJae Park authored
This commit links the DAMON sysfs interface to DAMON so that users can control DAMON via the interface. In detail, this commit makes writing 'on' to 'state' file constructs DAMON contexts based on values that users have written to relevant sysfs files and start the context. It supports only virtual address spaces monitoring at the moment, though. The files hierarchy of DAMON sysfs interface after this commit is shown below. In the below figure, parents-children relations 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 │ │ │ │ │ │ ... │ │ │ │ ... │ │ ... The usage is straightforward. Writing a number ('N') to each 'nr_*' file makes directories named '0' to 'N-1'. Users can construct DAMON contexts by writing proper values to the files in the straightforward manner and start each kdamond by writing 'on' to 'kdamonds/<N>/state'. Link: https://lkml.kernel.org/r/20220228081314.5770-5-sj@kernel.orgSigned-off-by: -
SeongJae Park authored
DAMON's debugfs-based user interface served very well, so far. However, it unnecessarily depends on debugfs, while DAMON is not aimed to be used for only debugging. Also, the interface receives multiple values via one file. For example, schemes file receives 18 values separated by white spaces. As a result, it is ineffient, hard to be used, and difficult to be extended. Especially, keeping backward compatibility of user space tools is getting only challenging. It would be better to implement another reliable and flexible interface and deprecate the debugfs interface in long term. To this end, this commit implements a stub of a part of the new user interface of DAMON using sysfs. Specifically, this commit implements the sysfs control parts for virtual address space monitoring. More specifically, the idea of the new interface is, using directory hierarchies and making one file for one value. The hierarchy that this commit is introducing is as below. In the below figure, parents-children relations 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 <N> to each 'nr' file makes directories of name <0> to <N-1> 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 kdamond will ask DAMON to start the constructed contexts. For a short example, using below commands for monitoring virtual address spaces 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 <workload>) > kdamonds/0/contexts/0/targets/0/pid_target # echo on > kdamonds/0/state Please note that this commit is implementing only the sysfs part stub as abovely 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.com Link: https://lkml.kernel.org/r/20220228081314.5770-4-sj@kernel.orgSigned-off-by:Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Xin Hao <xhao@linux.alibaba.com> Signed-off-by:
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SeongJae Park authored
This commit declares the number of legal values for each DAMON enum types to make traversals of such DAMON enum types easy and safe. Link: https://lkml.kernel.org/r/20220228081314.5770-3-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
Patch series "Introduce DAMON sysfs interface", v3. Introduction ============ DAMON's debugfs-based user interface (DAMON_DBGFS) served very well, so far. However, it unnecessarily depends on debugfs, while DAMON is not aimed to be used for only debugging. Also, the interface receives multiple values via one file. For example, schemes file receives 18 values. As a result, it is inefficient, hard to be used, and difficult to be extended. Especially, keeping backward compatibility of user space tools is getting only challenging. It would be better to implement another reliable and flexible interface and deprecate DAMON_DBGFS in long term. For the reason, this patchset introduces a sysfs-based new user interface of DAMON. The idea of the new interface is, using directory hierarchies and having one dedicated file for each value. For a short example, users can do the virtual address monitoring via the interface as below: # 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 <workload>) > kdamonds/0/contexts/0/targets/0/pid_target # echo on > kdamonds/0/state A brief representation of the files hierarchy of DAMON sysfs interface is as below. Childs are represented with indentation, directories are 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 │ │ │ │ │ │ │ regions/nr_regions │ │ │ │ │ │ │ │ 0/start,end │ │ │ │ │ │ │ │ ... │ │ │ │ │ │ ... │ │ │ │ │ schemes/nr_schemes │ │ │ │ │ │ 0/action │ │ │ │ │ │ │ access_pattern/ │ │ │ │ │ │ │ │ sz/min,max │ │ │ │ │ │ │ │ nr_accesses/min,max │ │ │ │ │ │ │ │ age/min,max │ │ │ │ │ │ │ quotas/ms,bytes,reset_interval_ms │ │ │ │ │ │ │ │ weights/sz_permil,nr_accesses_permil,age_permil │ │ │ │ │ │ │ watermarks/metric,interval_us,high,mid,low │ │ │ │ │ │ │ stats/nr_tried,sz_tried,nr_applied,sz_applied,qt_exceeds │ │ │ │ │ │ ... │ │ │ │ ... │ │ ... Detailed usage of the files will be described in the final Documentation patch of this patchset. Main Difference Between DAMON_DBGFS and DAMON_SYSFS --------------------------------------------------- At the moment, DAMON_DBGFS and DAMON_SYSFS provides same features. One important difference between them is their exclusiveness. DAMON_DBGFS works in an exclusive manner, so that no DAMON worker thread (kdamond) in the system can run concurrently and interfere somehow. For the reason, DAMON_DBGFS asks users to construct all monitoring contexts and start them at once. It's not a big problem but makes the operation a little bit complex and unflexible. For more flexible usage, DAMON_SYSFS moves the responsibility of preventing any possible interference to the admins and work in a non-exclusive manner. That is, users can configure and start contexts one by one. Note that DAMON respects both exclusive groups and non-exclusive groups of contexts, in a manner similar to that of reader-writer locks. That is, if any exclusive monitoring contexts (e.g., contexts that started via DAMON_DBGFS) are running, DAMON_SYSFS does not start new contexts, and vice versa. Future Plan of DAMON_DBGFS Deprecation ====================================== Once this patchset is merged, DAMON_DBGFS development will be frozen. That is, we will maintain it to work as is now so that no users will be break. But, it will not be extended to provide any new feature of DAMON. The support will be continued only until next LTS release. After that, we will drop DAMON_DBGFS. User-space Tooling Compatibility -------------------------------- As DAMON_SYSFS provides all features of DAMON_DBGFS, all user space tooling can move to DAMON_SYSFS. As we will continue supporting DAMON_DBGFS until next LTS kernel release, user space tools would have enough time to move to DAMON_SYSFS. The official user space tool, damo[1], is already supporting both DAMON_SYSFS and DAMON_DBGFS. Both correctness tests[2] and performance tests[3] of DAMON using DAMON_SYSFS also passed. [1] https://github.com/awslabs/damo [2] https://github.com/awslabs/damon-tests/tree/master/corr [3] https://github.com/awslabs/damon-tests/tree/master/perf Sequence of Patches =================== First two patches (patches 1-2) make core changes for DAMON_SYSFS. The first one (patch 1) allows non-exclusive DAMON contexts so that DAMON_SYSFS can work in non-exclusive mode, while the second one (patch 2) adds size of DAMON enum types so that DAMON API users can safely iterate the enums. Third patch (patch 3) implements basic sysfs stub for virtual address spaces monitoring. Note that this implements only sysfs files and DAMON is not linked. Fourth patch (patch 4) links the DAMON_SYSFS to DAMON so that users can control DAMON using the sysfs files. Following six patches (patches 5-10) implements other DAMON features that DAMON_DBGFS supports one by one (physical address space monitoring, DAMON-based operation schemes, schemes quotas, schemes prioritization weights, schemes watermarks, and schemes stats). Following patch (patch 11) adds a simple selftest for DAMON_SYSFS, and the final one (patch 12) documents DAMON_SYSFS. This patch (of 13): To avoid interference between DAMON contexts monitoring overlapping memory regions, damon_start() works in an exclusive manner. That is, damon_start() does nothing bug fails if any context that started by another instance of the function is still running. This makes its usage a little bit restrictive. However, admins could aware each DAMON usage and address such interferences on their own in some cases. This commit hence implements non-exclusive mode of the function and allows the callers to select the mode. Note that the exclusive groups and non-exclusive groups of contexts will respect each other in a manner similar to that of reader-writer locks. Therefore, this commit will not cause any behavioral change to the exclusive groups. Link: https://lkml.kernel.org/r/20220228081314.5770-1-sj@kernel.org Link: https://lkml.kernel.org/r/20220228081314.5770-2-sj@kernel.orgSigned-off-by: -
SeongJae Park authored
Before DAMON is merged in the mainline, the concept of 'regions update interval' has generalized to be used as the time interval for update of any monitoring operations related data structure, but the document has not updated properly. This commit updates the document for better consistency. Link: https://lkml.kernel.org/r/20220222170100.17068-4-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
In DAMON's early development stage before it be merged in the mainline, it was first designed to work exclusively with Idle page tracking to avoid any interference between each other. Later, but still before be merged in the mainline, because Idle page tracking is fully under the control of sysadmins, we made the resolving of conflict as the responsibility of sysadmins. The document is not updated for the change, though. This commit updates the document for that. Link: https://lkml.kernel.org/r/20220222170100.17068-3-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
Patch series "Docs/damon: Update documents for better consistency". Some of DAMON document are not properly updated for latest version. This patchset updates such parts. This patch (of 3): DAMON code calls the low level monitoring primitives implementations the monitoring operations. The documentation would have no problem at still calling those primitives implementation because there is no real difference in the concepts, but making it more consistent with the code would make it better. This commit therefore convert sentences in the doc specifically pointing the implementations of the primitives to call it monitoring operations. Link: https://lkml.kernel.org/r/20220222170100.17068-1-sj@kernel.org Link: https://lkml.kernel.org/r/20220222170100.17068-2-sj@kernel.orgSigned-off-by:
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tangmeng authored
In mm/Makefile has: obj-$(CONFIG_DAMON) += damon/ So that we don't need 'obj-$(CONFIG_DAMON) :=' in mm/damon/Makefile, delete it from mm/damon/Makefile. Link: https://lkml.kernel.org/r/20220221065255.19991-1-tangmeng@uniontech.comSigned-off-by:
tangmeng <tangmeng@uniontech.com> Cc: SeongJae Park <sj@kernel.org> Signed-off-by:
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SeongJae Park authored
Because DAMON debugfs interface and DAMON-based proactive reclaim are now using monitoring operations via registration mechanism, damon_{p,v}a_{target_valid,set_operations}() functions have no user. This commit clean them up. Link: https://lkml.kernel.org/r/20220215184603.1479-9-sj@kernel.orgSigned-off-by: -
SeongJae Park authored
DAMON kunit tests for DAMON debugfs interface fails because it still assumes setting empty monitoring operations makes DAMON debugfs interface believe the target of the context don't have pid. This commit fixes the kunit test fails by explicitly setting the context's monitoring operations with the operations for the physical address space, which let debugfs knows the target will not have pid. Link: https://lkml.kernel.org/r/20220215184603.1479-8-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
DAMON debugfs interface depends on monitoring operations for virtual address spaces because it knows if the target has pid or not by seeing if the context is configured to use one of the virtual address space monitoring operation functions. We can replace that check with 'enum damon_ops_id' now, to make it independent. This commit makes the change. Link: https://lkml.kernel.org/r/20220215184603.1479-7-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
This commit makes DAMON debugfs interface to select the registered monitoring operations for the physical address space or virtual address spaces depending on user requests instead of setting it on its own. Note that DAMON debugfs interface is still dependent to DAMON_VADDR with this change, because it is also using its symbol, 'damon_va_target_valid'. Link: https://lkml.kernel.org/r/20220215184603.1479-6-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
This commit makes DAMON_RECLAIM to select the registered monitoring operations for the physical address space instead of setting it on its own. This allows DAMON_RECLAIM be independent of DAMON_PADDR, but leave the dependency as is, because it's the only one monitoring operations it use, and therefore it makes no sense to build DAMON_RECLAIM without DAMON_PADDR. Link: https://lkml.kernel.org/r/20220215184603.1479-5-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
This commit makes the monitoring operations for the physical address space and virtual address spaces register themselves to DAMON in the subsys_initcall step. Later, in-kernel DAMON user code can use them via damon_select_ops() without have to unnecessarily depend on all possible monitoring operations implementations. Link: https://lkml.kernel.org/r/20220215184603.1479-4-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
In-kernel DAMON user code like DAMON debugfs interface should set 'struct damon_operations' of its 'struct damon_ctx' on its own. Therefore, the client code should depend on all supporting monitoring operations implementations that it could use. For example, DAMON debugfs interface depends on both vaddr and paddr, while some of the users are not always interested in both. To minimize such unnecessary dependencies, this commit makes the monitoring operations can be registered by implementing code and then dynamically selected by the user code without build-time dependency. Link: https://lkml.kernel.org/r/20220215184603.1479-3-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
Patch 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 (struct damon_primitive). This makes the user code dependent to all supporting monitoring primitives. For example, DAMON debugfs interface depends on both DAMON_VADDR and DAMON_PADDR, though some users have interest in only one use case. As more monitoring primitives are introduced, the problem will be bigger. To minimize such unnecessary dependency, this patchset makes monitoring primitives can be registered by the implemnting code and later dynamically searched and selected by the user code. In addition to that, this patchset renames monitoring primitives to monitoring operations, which is more easy to intuitively understand what it means and how it would be structed. This patch (of 8): DAMON has a set of callback functions called monitoring primitives and let it can be configured with various implementations for easy extension for different address spaces and usages. However, the word 'primitive' is not so explicit. Meanwhile, many other structs resembles similar purpose calls themselves 'operations'. To make the code easier to be understood, this commit renames 'damon_primitives' to 'damon_operations' before it is too late to rename. Link: https://lkml.kernel.org/r/20220215184603.1479-1-sj@kernel.org Link: https://lkml.kernel.org/r/20220215184603.1479-2-sj@kernel.orgSigned-off-by:
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Baolin Wang authored
It will never get a NULL page by pte_page() as discussed in thread [1], thus remove the redundant page validation to fix below Smatch static checker warning. mm/damon/vaddr.c:405 damon_hugetlb_mkold() warn: 'page' can't be NULL. [1] https://lore.kernel.org/linux-mm/20220106091200.GA14564@kili/ Link: https://lkml.kernel.org/r/6d32f7d201b8970d53f51b6c5717d472aed2987c.1642386715.git.baolin.wang@linux.alibaba.comSigned-off-by:Baolin Wang <baolin.wang@linux.alibaba.com> Reported-by:
Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by:
David Rientjes <rientjes@google.com> Acked-by:
Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by:
Miaohe Lin <linmiaohe@huawei.com> Signed-off-by:
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SeongJae Park authored
DAMON asks each monitoring target ('struct damon_target') to have one 'unsigned long' integer called 'id', which should be unique among the targets of same monitoring context. Meaning of it is, however, totally up to the monitoring primitives that registered to the monitoring context. For example, the virtual address spaces monitoring primitives treats the id as a 'struct pid' pointer. This makes the code flexible, but ugly, not well-documented, and type-unsafe[1]. Also, identification of each target can be done via its index. For the reason, this commit removes the concept and uses clear type definition. For now, only 'struct pid' pointer is used for the virtual address spaces monitoring. If DAMON is extended in future so that we need to put another identifier field in the struct, we will use a union for such primitives-dependent fields and document which primitives are using which type. [1] https://lore.kernel.org/linux-mm/20211013154535.4aaeaaf9d0182922e405dd1e@linux-foundation.org/ Link: https://lkml.kernel.org/r/20211230100723.2238-5-sj@kernel.orgSigned-off-by: -
SeongJae Park authored
damon_set_targets() function is defined in the core for general use cases, but called from only dbgfs. Also, because the function is for general use cases, dbgfs does additional handling of pid type target id case. To make the situation simpler, this commit moves the function into dbgfs and makes it to do the pid type case handling on its own. Link: https://lkml.kernel.org/r/20211230100723.2238-4-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
A previous commit made init_regions debugfs file to use target index instead of target id for specifying the target of the init regions. This commit updates the usage document to reflect the change. Link: https://lkml.kernel.org/r/20211230100723.2238-3-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
Patch series "Remove the type-unclear target id concept". DAMON asks each monitoring target ('struct damon_target') to have one 'unsigned long' integer called 'id', which should be unique among the targets of same monitoring context. Meaning of it is, however, totally up to the monitoring primitives that registered to the monitoring context. For example, the virtual address spaces monitoring primitives treats the id as a 'struct pid' pointer. This makes the code flexible but ugly, not well-documented, and type-unsafe[1]. Also, identification of each target can be done via its index. For the reason, this patchset removes the concept and uses clear type definition. [1] https://lore.kernel.org/linux-mm/20211013154535.4aaeaaf9d0182922e405dd1e@linux-foundation.org/ This patch (of 4): Target id is a 'unsigned long' data, which can be interpreted differently by each monitoring primitives. For example, it means 'struct pid *' for the virtual address spaces monitoring, while it means nothing but an integer to be displayed to debugfs interface users for the physical address space monitoring. It's flexible but makes code ugly and type-unsafe[1]. To be prepared for eventual removal of the concept, this commit removes a use case of the concept in 'init_regions' debugfs file handling. In detail, this commit replaces use of the id with the index of each target in the context's targets list. [1] https://lore.kernel.org/linux-mm/20211013154535.4aaeaaf9d0182922e405dd1e@linux-foundation.org/ Link: https://lkml.kernel.org/r/20211230100723.2238-1-sj@kernel.org Link: https://lkml.kernel.org/r/20211230100723.2238-2-sj@kernel.orgSigned-off-by: -
Miaohe Lin authored
The local variable ret is always 0. Remove it to make code more tight. Link: https://lkml.kernel.org/r/20220125124833.39718-1-linmiaohe@huawei.comSigned-off-by:
Muchun Song <songmuchun@bytedance.com> Signed-off-by:
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Marco Elver authored
Allow the use of a deferrable timer, which does not force CPU wake-ups when the system is idle. A consequence is that the sample interval becomes very unpredictable, to the point that it is not guaranteed that the KFENCE KUnit test still passes. Nevertheless, on power-constrained systems this may be preferable, so let's give the user the option should they accept the above trade-off. Link: https://lkml.kernel.org/r/20220308141415.3168078-1-elver@google.comSigned-off-by:
Marco Elver <elver@google.com> Reviewed-by:
Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by:
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Peng Liu authored
When CONFIG_KFENCE_NUM_OBJECTS is set to a big number, kfence kunit-test-case test_gfpzero will eat up nearly all the CPU's resources and rcu_stall is reported as the following log which is cut from a physical server. rcu: INFO: rcu_sched self-detected stall on CPU rcu: 68-....: (14422 ticks this GP) idle=6ce/1/0x4000000000000002 softirq=592/592 fqs=7500 (t=15004 jiffies g=10677 q=20019) Task dump for CPU 68: task:kunit_try_catch state:R running task stack: 0 pid: 9728 ppid: 2 flags:0x0000020a Call trace: dump_backtrace+0x0/0x1e4 show_stack+0x20/0x2c sched_show_task+0x148/0x170 ... rcu_sched_clock_irq+0x70/0x180 update_process_times+0x68/0xb0 tick_sched_handle+0x38/0x74 ... gic_handle_irq+0x78/0x2c0 el1_irq+0xb8/0x140 kfree+0xd8/0x53c test_alloc+0x264/0x310 [kfence_test] test_gfpzero+0xf4/0x840 [kfence_test] kunit_try_run_case+0x48/0x20c kunit_generic_run_threadfn_adapter+0x28/0x34 kthread+0x108/0x13c ret_from_fork+0x10/0x18 To avoid rcu_stall and unacceptable latency, a schedule point is added to test_gfpzero. Link: https://lkml.kernel.org/r/20220309083753.1561921-4-liupeng256@huawei.comSigned-off-by:
Peng Liu <liupeng256@huawei.com> Reviewed-by:
Brendan Higgins <brendanhiggins@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Wang Kefeng <wangkefeng.wang@huawei.com> Cc: Daniel Latypov <dlatypov@google.com> Cc: David Gow <davidgow@google.com> Signed-off-by:
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Peng Liu authored
In function kunit_test_timeout, it is declared "300 * MSEC_PER_SEC" represent 5min. However, it is wrong when dealing with arm64 whose default HZ = 250, or some other situations. Use msecs_to_jiffies to fix this, and kunit_test_timeout will work as desired. Link: https://lkml.kernel.org/r/20220309083753.1561921-3-liupeng256@huawei.com Fixes: 5f3e0620 ("kunit: test: add support for test abort") Signed-off-by:
Daniel Latypov <dlatypov@google.com> Reviewed-by:
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Peng Liu authored
Patch series "kunit: fix a UAF bug and do some optimization", v2. This series is to fix UAF (use after free) when running kfence test case test_gfpzero, which is time costly. This UAF bug can be easily triggered by setting CONFIG_KFENCE_NUM_OBJECTS = 65535. Furthermore, some optimization for kunit tests has been done. This patch (of 3): Kunit will create a new thread to run an actual test case, and the main process will wait for the completion of the actual test thread until overtime. The variable "struct kunit test" has local property in function kunit_try_catch_run, and will be used in the test case thread. Task kunit_try_catch_run will free "struct kunit test" when kunit runs overtime, but the actual test case is still run and an UAF bug will be triggered. The above problem has been both observed in a physical machine and qemu platform when running kfence kunit tests. The problem can be triggered when setting CONFIG_KFENCE_NUM_OBJECTS = 65535. Under this setting, the test case test_gfpzero will cost hours and kunit will run to overtime. The follows show the panic log. BUG: unable to handle page fault for address: ffffffff82d882e9 Call Trace: kunit_log_append+0x58/0xd0 ... test_alloc.constprop.0.cold+0x6b/0x8a [kfence_test] test_gfpzero.cold+0x61/0x8ab [kfence_test] kunit_try_run_case+0x4c/0x70 kunit_generic_run_threadfn_adapter+0x11/0x20 kthread+0x166/0x190 ret_from_fork+0x22/0x30 Kernel panic - not syncing: Fatal exception Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 To solve this problem, the test case thread should be stopped when the kunit frame runs overtime. The stop signal will send in function kunit_try_catch_run, and test_gfpzero will handle it. Link: https://lkml.kernel.org/r/20220309083753.1561921-1-liupeng256@huawei.com Link: https://lkml.kernel.org/r/20220309083753.1561921-2-liupeng256@huawei.comSigned-off-by:
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Tianchen Ding authored
Allow enabling KFENCE after system startup by allocating its pool via the page allocator. This provides the flexibility to enable KFENCE even if it wasn't enabled at boot time. Link: https://lkml.kernel.org/r/20220307074516.6920-3-dtcccc@linux.alibaba.comSigned-off-by:
Tianchen Ding <dtcccc@linux.alibaba.com> Reviewed-by:
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Tianchen Ding authored
Patch series "provide the flexibility to enable KFENCE", v3. If CONFIG_CONTIG_ALLOC is not supported, we fallback to try alloc_pages_exact(). Allocating pages in this way has limits about MAX_ORDER (default 11). So we will not support allocating kfence pool after system startup with a large KFENCE_NUM_OBJECTS. When handling failures in kfence_init_pool_late(), we pair free_pages_exact() to alloc_pages_exact() for compatibility consideration, though it actually does the same as free_contig_range(). This patch (of 2): If once KFENCE is disabled by: echo 0 > /sys/module/kfence/parameters/sample_interval KFENCE could never be re-enabled until next rebooting. Allow re-enabling it by writing a positive num to sample_interval. Link: https://lkml.kernel.org/r/20220307074516.6920-1-dtcccc@linux.alibaba.com Link: https://lkml.kernel.org/r/20220307074516.6920-2-dtcccc@linux.alibaba.comSigned-off-by:
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