lwn.git/kernel/trace, branch docs-5.17-3

Merge tag 'trace-v5.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2022-01-23T06:07:02+00:00

Pull ftrace fix from Steven Rostedt: "Fix s390 breakage from sorting mcount tables. The latest merge of the tracing tree sorts the mcount table at build time. But s390 appears to do things differently (like always) and replaces the sorted table back to the original unsorted one. As the ftrace algorithm depends on it being sorted, bad things happen when it is not, and s390 experienced those bad things. Add a new config to tell the boot if the mcount table is sorted or not, and allow s390 to opt out of it" * tag 'trace-v5.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace: Fix assuming build time sort works for s390

ftrace: Fix assuming build time sort works for s390

2022-01-23T05:10:09+00:00

To speed up the boot process, as mcount_loc needs to be sorted for ftrace to work properly, sorting it at build time is more efficient than boot up and can save milliseconds of time. Unfortunately, this change broke s390 as it will modify the mcount_loc location after the sorting takes place and will put back the unsorted locations. Since the sorting is skipped at boot up if it is believed that it was sorted at run time, ftrace can crash as its algorithms are dependent on the list being sorted. Add a new config BUILDTIME_MCOUNT_SORT that is set when BUILDTIME_TABLE_SORT but not if S390 is set. Use this config to determine if sorting should take place at boot up. Link: https://lore.kernel.org/all/yt9dee51ctfn.fsf@linux.ibm.com/ Fixes: 72b3942a173c ("scripts: ftrace - move the sort-processing in ftrace_init") Reported-by: Sven Schnelle Tested-by: Heiko Carstens Signed-off-by: Steven Rostedt (Google)

Merge tag 'trace-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2022-01-16T08:15:32+00:00

Pull tracing updates from Steven Rostedt: "New: - The Real Time Linux Analysis (RTLA) tool is added to the tools directory. - Can safely filter on user space pointers with: field.ustring ~ "match-string" - eprobes can now be filtered like any other event. - trace_marker(_raw) now uses stream_open() to allow multiple threads to safely write to it. Note, this could possibly break existing user space, but we will not know until we hear about it, and then can revert the change if need be. - New field in events to display when bottom halfs are disabled. - Sorting of the ftrace functions are now done at compile time instead of at bootup. Infrastructure changes to support future efforts: - Added __rel_loc type for trace events. Similar to __data_loc but the offset to the dynamic data is based off of the location of the descriptor and not the beginning of the event. Needed for user defined events. - Some simplification of event trigger code. - Make synthetic events process its callback better to not hinder other event callbacks that are registered. Needed for user defined events. And other small fixes and cleanups" * tag 'trace-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (50 commits) tracing: Add ustring operation to filtering string pointers rtla: Add rtla timerlat hist documentation rtla: Add rtla timerlat top documentation rtla: Add rtla timerlat documentation rtla: Add rtla osnoise hist documentation rtla: Add rtla osnoise top documentation rtla: Add rtla osnoise man page rtla: Add Documentation rtla/timerlat: Add timerlat hist mode rtla: Add timerlat tool and timelart top mode rtla/osnoise: Add the hist mode rtla/osnoise: Add osnoise top mode rtla: Add osnoise tool rtla: Helper functions for rtla rtla: Real-Time Linux Analysis tool tracing/osnoise: Properly unhook events if start_per_cpu_kthreads() fails tracing: Remove duplicate warnings when calling trace_create_file() tracing/kprobes: 'nmissed' not showed correctly for kretprobe tracing: Add test for user space strings when filtering on string pointers tracing: Have syscall trace events use trace_event_buffer_lock_reserve() ...

Merge branch 'akpm' (patches from Andrew)

2022-01-15T18:37:06+00:00

Merge misc updates from Andrew Morton: "146 patches. Subsystems affected by this patch series: kthread, ia64, scripts, ntfs, squashfs, ocfs2, vfs, and mm (slab-generic, slab, kmemleak, dax, kasan, debug, pagecache, gup, shmem, frontswap, memremap, memcg, selftests, pagemap, dma, vmalloc, memory-failure, hugetlb, userfaultfd, vmscan, mempolicy, oom-kill, hugetlbfs, migration, thp, ksm, page-poison, percpu, rmap, zswap, zram, cleanups, hmm, and damon)" * emailed patches from Andrew Morton : (146 commits) mm/damon: hide kernel pointer from tracepoint event mm/damon/vaddr: hide kernel pointer from damon_va_three_regions() failure log mm/damon/vaddr: use pr_debug() for damon_va_three_regions() failure logging mm/damon/dbgfs: remove an unnecessary variable mm/damon: move the implementation of damon_insert_region to damon.h mm/damon: add access checking for hugetlb pages Docs/admin-guide/mm/damon/usage: update for schemes statistics mm/damon/dbgfs: support all DAMOS stats Docs/admin-guide/mm/damon/reclaim: document statistics parameters mm/damon/reclaim: provide reclamation statistics mm/damon/schemes: account how many times quota limit has exceeded mm/damon/schemes: account scheme actions that successfully applied mm/damon: remove a mistakenly added comment for a future feature Docs/admin-guide/mm/damon/usage: update for kdamond_pid and (mk|rm)_contexts Docs/admin-guide/mm/damon/usage: mention tracepoint at the beginning Docs/admin-guide/mm/damon/usage: remove redundant information Docs/admin-guide/mm/damon/usage: update for scheme quotas and watermarks mm/damon: convert macro functions to static inline functions mm/damon: modify damon_rand() macro to static inline function mm/damon: move damon_rand() definition into damon.h ...

trace/hwlat: make use of the helper function kthread_run_on_cpu()

2022-01-15T14:30:24+00:00

Replace kthread_create_on_cpu/wake_up_process() with kthread_run_on_cpu() to simplify the code. Link: https://lkml.kernel.org/r/20211022025711.3673-7-caihuoqing@baidu.com Signed-off-by: Cai Huoqing Cc: Bernard Metzler Cc: Daniel Bristot de Oliveira Cc: Davidlohr Bueso Cc: Doug Ledford Cc: Ingo Molnar Cc: Jason Gunthorpe Cc: Joel Fernandes (Google) Cc: Josh Triplett Cc: Lai Jiangshan Cc: Mathieu Desnoyers Cc: "Paul E . McKenney" Cc: Steven Rostedt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

trace/osnoise: make use of the helper function kthread_run_on_cpu()

2022-01-15T14:30:24+00:00

Replace kthread_create_on_cpu/wake_up_process() with kthread_run_on_cpu() to simplify the code. Link: https://lkml.kernel.org/r/20211022025711.3673-6-caihuoqing@baidu.com Signed-off-by: Cai Huoqing Cc: Bernard Metzler Cc: Daniel Bristot de Oliveira Cc: Davidlohr Bueso Cc: Doug Ledford Cc: Ingo Molnar Cc: Jason Gunthorpe Cc: Joel Fernandes (Google) Cc: Josh Triplett Cc: Lai Jiangshan Cc: Mathieu Desnoyers Cc: "Paul E . McKenney" Cc: Steven Rostedt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ring-buffer: make use of the helper function kthread_run_on_cpu()

2022-01-15T14:30:23+00:00

Replace kthread_create/kthread_bind/wake_up_process() with kthread_run_on_cpu() to simplify the code. Link: https://lkml.kernel.org/r/20211022025711.3673-4-caihuoqing@baidu.com Signed-off-by: Cai Huoqing Cc: Bernard Metzler Cc: Daniel Bristot de Oliveira Cc: Davidlohr Bueso Cc: Doug Ledford Cc: Ingo Molnar Cc: Jason Gunthorpe Cc: Joel Fernandes (Google) Cc: Josh Triplett Cc: Lai Jiangshan Cc: Mathieu Desnoyers Cc: "Paul E . McKenney" Cc: Steven Rostedt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

tracing: Add ustring operation to filtering string pointers

2022-01-14T08:42:24+00:00

Since referencing user space pointers is special, if the user wants to filter on a field that is a pointer to user space, then they need to specify it. Add a ".ustring" attribute to the field name for filters to state that the field is pointing to user space such that the kernel can take the appropriate action to read that pointer. Link: https://lore.kernel.org/all/yt9d8rvmt2jq.fsf@linux.ibm.com/ Fixes: 77360f9bbc7e ("tracing: Add test for user space strings when filtering on string pointers") Tested-by: Sven Schnelle Signed-off-by: Steven Rostedt

tracing/osnoise: Properly unhook events if start_per_cpu_kthreads() fails

2022-01-13T22:02:42+00:00

If start_per_cpu_kthreads() called from osnoise_workload_start() returns error, event hooks are left in broken state: unhook_irq_events() called but unhook_thread_events() and unhook_softirq_events() not called, and trace_osnoise_callback_enabled flag not cleared. On the next tracer enable, hooks get not installed due to trace_osnoise_callback_enabled flag. And on the further tracer disable an attempt to remove non-installed hooks happened, hitting a WARN_ON_ONCE() in tracepoint_remove_func(). Fix the error path by adding the missing part of cleanup. While at this, introduce osnoise_unhook_events() to avoid code duplication between this error path and normal tracer disable. Link: https://lkml.kernel.org/r/20220109153459.3701773-1-nikita.yushchenko@virtuozzo.com Cc: stable@vger.kernel.org Fixes: bce29ac9ce0b ("trace: Add osnoise tracer") Acked-by: Daniel Bristot de Oliveira Signed-off-by: Nikita Yushchenko Signed-off-by: Steven Rostedt

tracing: Remove duplicate warnings when calling trace_create_file()

2022-01-13T22:02:42+00:00

Since the same warning message is already printed in the trace_create_file() function, there is no need to print it again. Link: https://lkml.kernel.org/r/20220109162232.361747-1-ytcoode@gmail.com Signed-off-by: Yuntao Wang Signed-off-by: Steven Rostedt