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2022-04-22printk: add functions to prefer direct printingJohn Ogness9-2/+78
Once kthread printing is available, console printing will no longer occur in the context of the printk caller. However, there are some special contexts where it is desirable for the printk caller to directly print out kernel messages. Using pr_flush() to wait for threaded printers is only possible if the caller is in a sleepable context and the kthreads are active. That is not always the case. Introduce printk_prefer_direct_enter() and printk_prefer_direct_exit() functions to explicitly (and globally) activate/deactivate preferred direct console printing. The term "direct console printing" refers to printing to all enabled consoles from the context of the printk caller. The term "prefer" is used because this type of printing is only best effort. If the console is currently locked or other printers are already actively printing, the printk caller will need to rely on the other contexts to handle the printing. This preferred direct printing is how all printing has been handled until now (unless it was explicitly deferred). When kthread printing is introduced, there may be some unanticipated problems due to kthreads being unable to flush important messages. In order to minimize such risks, preferred direct printing is activated for the primary important messages when the system experiences general types of major errors. These are: - emergency reboot/shutdown - cpu and rcu stalls - hard and soft lockups - hung tasks - warn - sysrq Note that since kthread printing does not yet exist, no behavior changes result from this commit. This is only implementing the counter and marking the various places where preferred direct printing is active. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> # for RCU Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220421212250.565456-13-john.ogness@linutronix.de
2022-04-22printk: add pr_flush()John Ogness2-0/+90
Provide a might-sleep function to allow waiting for console printers to catch up to the latest logged message. Use pr_flush() whenever it is desirable to get buffered messages printed before continuing: suspend_console(), resume_console(), console_stop(), console_start(), console_unblank(). Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220421212250.565456-12-john.ogness@linutronix.de
2022-04-22printk: move buffer definitions into console_emit_next_record() callerJohn Ogness1-17/+43
Extended consoles print extended messages and do not print messages about dropped records. Non-extended consoles print "normal" messages as well as extra messages about dropped records. Currently the buffers for these various message types are defined within the functions that might use them and their usage is based upon the CON_EXTENDED flag. This will be a problem when moving to kthread printers because each printer must be able to provide its own buffers. Move all the message buffer definitions outside of console_emit_next_record(). The caller knows if extended or dropped messages should be printed and can specify the appropriate buffers to use. The console_emit_next_record() and call_console_driver() functions can know what to print based on whether specified buffers are non-NULL. With this change, buffer definition/allocation/specification is separated from the code that does the various types of string printing. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220421212250.565456-11-john.ogness@linutronix.de
2022-04-22printk: refactor and rework printing logicJohn Ogness2-213/+230
Refactor/rework printing logic in order to prepare for moving to threaded console printing. - Move @console_seq into struct console so that the current "position" of each console can be tracked individually. - Move @console_dropped into struct console so that the current drop count of each console can be tracked individually. - Modify printing logic so that each console independently loads, prepares, and prints its next record. - Remove exclusive_console logic. Since console positions are handled independently, replaying past records occurs naturally. - Update the comments explaining why preemption is disabled while printing from printk() context. With these changes, there is a change in behavior: the console replaying the log (formerly exclusive console) will no longer block other consoles. New messages appear on the other consoles while the newly added console is still replaying. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220421212250.565456-10-john.ogness@linutronix.de
2022-04-22printk: add con_printk() macro for console detailsJohn Ogness1-6/+7
It is useful to generate log messages that include details about the related console. Rather than duplicate the code to assemble the details, put that code into a macro con_printk(). Once console printers become threaded, this macro will find more users. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220421212250.565456-9-john.ogness@linutronix.de
2022-04-22printk: call boot_delay_msec() in printk_delay()John Ogness1-3/+4
boot_delay_msec() is always called immediately before printk_delay() so just call it from within printk_delay(). Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220421212250.565456-8-john.ogness@linutronix.de
2022-04-22printk: get caller_id/timestamp after migration disableJohn Ogness1-4/+6
Currently the local CPU timestamp and caller_id for the record are collected while migration is enabled. Since this information is CPU-specific, it should be collected with migration disabled. Migration is disabled immediately after collecting this information anyway, so just move the information collection to after the migration disabling. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220421212250.565456-7-john.ogness@linutronix.de
2022-04-22printk: wake waiters for safe and NMI contextsJohn Ogness1-12/+16
When printk() is called from safe or NMI contexts, it will directly store the record (vprintk_store()) and then defer the console output. However, defer_console_output() only causes console printing and does not wake any waiters of new records. Wake waiters from defer_console_output() so that they also are aware of the new records from safe and NMI contexts. Fixes: 03fc7f9c99c1 ("printk/nmi: Prevent deadlock when accessing the main log buffer in NMI") Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220421212250.565456-6-john.ogness@linutronix.de
2022-04-22printk: wake up all waitersJohn Ogness1-1/+1
There can be multiple tasks waiting for new records. They should all be woken. Use wake_up_interruptible_all() instead of wake_up_interruptible(). Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220421212250.565456-5-john.ogness@linutronix.de
2022-04-22printk: add missing memory barrier to wake_up_klogd()John Ogness1-3/+36
It is important that any new records are visible to preparing waiters before the waker checks if the wait queue is empty. Otherwise it is possible that: - there are new records available - the waker sees an empty wait queue and does not wake - the preparing waiter sees no new records and begins to wait This is exactly the problem that the function description of waitqueue_active() warns about. Use wq_has_sleeper() instead of waitqueue_active() because it includes the necessary full memory barrier. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220421212250.565456-4-john.ogness@linutronix.de
2022-04-22printk: cpu sync always disable interruptsJohn Ogness1-9/+9
The CPU sync functions are a NOP for !CONFIG_SMP. But for !CONFIG_SMP they still need to disable interrupts in order to preserve context within the CPU sync sections. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220421212250.565456-3-john.ogness@linutronix.de
2022-04-22printk: rename cpulock functionsJohn Ogness4-60/+73
Since the printk cpulock is CPU-reentrant and since it is used in all contexts, its usage must be carefully considered and most likely will require programming locklessly. To avoid mistaking the printk cpulock as a typical lock, rename it to cpu_sync. The main functions then become: printk_cpu_sync_get_irqsave(flags); printk_cpu_sync_put_irqrestore(flags); Add extra notes of caution in the function description to help developers understand the requirements for correct usage. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220421212250.565456-2-john.ogness@linutronix.de
2022-03-23Merge tag 'printk-for-5.18' of ↵Linus Torvalds5-36/+161
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk updates from Petr Mladek: - Make %pK behave the same as %p for kptr_restrict == 0 also with no_hash_pointers parameter - Ignore the default console in the device tree also when console=null or console="" is used on the command line - Document console=null and console="" behavior - Prevent a deadlock and a livelock caused by console_lock in panic() - Make console_lock available for panicking CPU - Fast query for the next to-be-used sequence number - Use the expected return values in printk.devkmsg __setup handler - Use the correct atomic operations in wake_up_klogd() irq_work handler - Avoid possible unaligned access when handling %4cc printing format * tag 'printk-for-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: printk: fix return value of printk.devkmsg __setup handler vsprintf: Fix %pK with kptr_restrict == 0 printk: make suppress_panic_printk static printk: Set console_set_on_cmdline=1 when __add_preferred_console() is called with user_specified == true Docs: printk: add 'console=null|""' to admin/kernel-parameters printk: use atomic updates for klogd work printk: Drop console_sem during panic printk: Avoid livelock with heavy printk during panic printk: disable optimistic spin during panic printk: Add panic_in_progress helper vsprintf: Move space out of string literals in fourcc_string() vsprintf: Fix potential unaligned access printk: ringbuffer: Improve prb_next_seq() performance
2022-03-23cacheflush.h: Add forward declaration for struct folioHerbert Xu1-0/+2
The struct folio is not declared in cacheflush.h so we need to provide a forward declaration as otherwise users of this header file may get warnings. Reported-by: Guenter Roeck <linux@roeck-us.net> Fixes: 522a0032af00 ("Add linux/cacheflush.h") Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22Merge tag 'folio-5.18b' of git://git.infradead.org/users/willy/pagecacheLinus Torvalds94-875/+849
Pull filesystem folio updates from Matthew Wilcox: "Primarily this series converts some of the address_space operations to take a folio instead of a page. Notably: - a_ops->is_partially_uptodate() takes a folio instead of a page and changes the type of the 'from' and 'count' arguments to make it obvious they're bytes. - a_ops->invalidatepage() becomes ->invalidate_folio() and has a similar type change. - a_ops->launder_page() becomes ->launder_folio() - a_ops->set_page_dirty() becomes ->dirty_folio() and adds the address_space as an argument. There are a couple of other misc changes up front that weren't worth separating into their own pull request" * tag 'folio-5.18b' of git://git.infradead.org/users/willy/pagecache: (53 commits) fs: Remove aops ->set_page_dirty fb_defio: Use noop_dirty_folio() fs: Convert __set_page_dirty_no_writeback to noop_dirty_folio fs: Convert __set_page_dirty_buffers to block_dirty_folio nilfs: Convert nilfs_set_page_dirty() to nilfs_dirty_folio() mm: Convert swap_set_page_dirty() to swap_dirty_folio() ubifs: Convert ubifs_set_page_dirty to ubifs_dirty_folio f2fs: Convert f2fs_set_node_page_dirty to f2fs_dirty_node_folio f2fs: Convert f2fs_set_data_page_dirty to f2fs_dirty_data_folio f2fs: Convert f2fs_set_meta_page_dirty to f2fs_dirty_meta_folio afs: Convert afs_dir_set_page_dirty() to afs_dir_dirty_folio() btrfs: Convert extent_range_redirty_for_io() to use folios fs: Convert trivial uses of __set_page_dirty_nobuffers to filemap_dirty_folio btrfs: Convert from set_page_dirty to dirty_folio fscache: Convert fscache_set_page_dirty() to fscache_dirty_folio() fs: Add aops->dirty_folio fs: Remove aops->launder_page orangefs: Convert launder_page to launder_folio nfs: Convert from launder_page to launder_folio fuse: Convert from launder_page to launder_folio ...
2022-03-22Merge tag 'folio-5.18c' of git://git.infradead.org/users/willy/pagecacheLinus Torvalds100-3020/+2900
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() ...
2022-03-22Merge branch 'akpm' (patches from Andrew)Linus Torvalds262-2646/+6762
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 ...
2022-03-22mm/damon/sysfs: remove repeat container_of() in damon_sysfs_kdamond_release()Xin Hao1-1/+1
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.com Signed-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>
2022-03-22Docs/ABI/testing: add DAMON sysfs interface ABI documentSeongJae Park2-0/+275
This commit adds DAMON sysfs interface ABI document under Documentation/ABI/testing. Link: https://lkml.kernel.org/r/20220228081314.5770-14-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22Docs/admin-guide/mm/damon/usage: document DAMON sysfs interfaceSeongJae Park1-6/+344
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.org Signed-off-by: SeongJae Park <sj@kernel.org> 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22selftests/damon: add a test for DAMON sysfs interfaceSeongJae Park2-0/+307
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.org Signed-off-by: SeongJae Park <sj@kernel.org> 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon/sysfs: support DAMOS statsSeongJae Park1-0/+150
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.org Signed-off-by: SeongJae Park <sj@kernel.org> 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon/sysfs: support DAMOS watermarksSeongJae Park1-5/+215
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.org Signed-off-by: SeongJae Park <sj@kernel.org> 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> Cc: Colin Ian King <colin.i.king@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon/sysfs: support schemes prioritizationSeongJae Park1-3/+149
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.org Signed-off-by: SeongJae Park <sj@kernel.org> 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon/sysfs: support DAMOS quotasSeongJae Park1-1/+145
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.org Signed-off-by: SeongJae Park <sj@kernel.org> 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon/sysfs: support DAMON-based Operation SchemesSeongJae Park1-0/+410
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.org Signed-off-by: SeongJae Park <sj@kernel.org> 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon/sysfs: support the physical address space monitoringSeongJae Park1-5/+271
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.org Signed-off-by: SeongJae Park <sj@kernel.org> 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon/sysfs: link DAMON for virtual address spaces monitoringSeongJae Park1-3/+189
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.org Signed-off-by: SeongJae Park <sj@kernel.org> 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon: implement a minimal stub for sysfs-based DAMON interfaceSeongJae Park3-0/+1092
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.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon/core: add number of each enum type valuesSeongJae Park1-0/+4
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.org Signed-off-by: SeongJae Park <sj@kernel.org> 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon/core: allow non-exclusive DAMON start/stopSeongJae Park4-11/+18
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.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: David Rientjes <rientjes@google.com> Cc: Xin Hao <xhao@linux.alibaba.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22Docs/damon: update outdated term 'regions update interval'SeongJae Park2-8/+10
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.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22Docs/vm/damon/design: update DAMON-Idle Page Tracking interference handlingSeongJae Park1-3/+4
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.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22Docs/vm/damon: call low level monitoring primitives the operationsSeongJae Park2-13/+13
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.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon: remove unnecessary CONFIG_DAMON optiontangmeng1-1/+1
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.com Signed-off-by: tangmeng <tangmeng@uniontech.com> Cc: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon/paddr,vaddr: remove damon_{p,v}a_{target_valid,set_operations}()SeongJae Park3-43/+2
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.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Xin Hao <xhao@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon/dbgfs-test: fix is_target_id() changeSeongJae Park1-1/+3
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.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Xin Hao <xhao@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon/dbgfs: use operations id for knowing if the target has pidSeongJae Park1-3/+3
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.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Xin Hao <xhao@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon/dbgfs: use damon_select_ops() instead of damon_{v,p}a_set_operations()SeongJae Park1-3/+13
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.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Xin Hao <xhao@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon/reclaim: use damon_select_ops() instead of ↵SeongJae Park1-1/+3
damon_{v,p}a_set_operations() 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.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Xin Hao <xhao@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon/paddr,vaddr: register themselves to DAMON in subsys_initcallSeongJae Park2-0/+40
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.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Xin Hao <xhao@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon: let monitoring operations can be registered and selectedSeongJae Park2-0/+84
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.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Xin Hao <xhao@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon: rename damon_primitives to damon_operationsSeongJae Park12-95/+96
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.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Xin Hao <xhao@linux.alibaba.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon: remove redundant page validationBaolin Wang1-6/+0
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.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: SeongJae Park <sj@kernel.org> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon: remove the target id conceptSeongJae Park8-128/+133
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.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon/core: move damon_set_targets() into dbgfsSeongJae Park5-54/+52
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.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22Docs/admin-guide/mm/damon/usage: update for changed initail_regions file inputSeongJae Park1-10/+14
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.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/damon/dbgfs/init_regions: use target index instead of target idSeongJae Park2-23/+22
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.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm/hmm.c: remove unneeded local variable retMiaohe Lin1-2/+1
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.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22kfence: allow use of a deferrable timerMarco Elver3-2/+37
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.com Signed-off-by: Marco Elver <elver@google.com> Reviewed-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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