linux/tools/testing/selftests/user_events
Linus Torvalds 31e5f934ff Tracing updates for v6.7:
- Remove eventfs_file descriptor
 
   This is the biggest change, and the second part of making eventfs
   create its files dynamically.
 
   In 6.6 the first part was added, and that maintained a one to one
   mapping between eventfs meta descriptors and the directories and
   file inodes and dentries that were dynamically created. The
   directories were represented by a eventfs_inode and the files
   were represented by a eventfs_file.
 
   In v6.7 the eventfs_file is removed. As all events have the same
   directory make up (sched_switch has an "enable", "id", "format",
   etc files), the handing of what files are underneath each leaf
   eventfs directory is moved back to the tracing subsystem via a
   callback. When a event is added to the eventfs, it registers
   an array of evenfs_entry's. These hold the names of the files and
   the callbacks to call when the file is referenced. The callback gets
   the name so that the same callback may be used by multiple files.
   The callback then supplies the filesystem_operations structure needed
   to create this file.
 
   This has brought the memory footprint of creating multiple eventfs
   instances down by 2 megs each!
 
 - User events now has persistent events that are not associated
   to a single processes. These are privileged events that hang around
   even if no process is attached to them.
 
 - Clean up of seq_buf.
   There's talk about using seq_buf more to replace strscpy() and friends.
   But this also requires some minor modifications of seq_buf to be
   able to do this.
 
 - Expand instance ring buffers individually
   Currently if boot up creates an instance, and a trace event is
   enabled on that instance, the ring buffer for that instance and the
   top level ring buffer are expanded (1.4 MB per CPU). This wastes
   memory as this happens when nothing is using the top level instance.
 
 - Other minor clean ups and fixes.
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Merge tag 'trace-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing updates from Steven Rostedt:

 - Remove eventfs_file descriptor

   This is the biggest change, and the second part of making eventfs
   create its files dynamically.

   In 6.6 the first part was added, and that maintained a one to one
   mapping between eventfs meta descriptors and the directories and file
   inodes and dentries that were dynamically created. The directories
   were represented by a eventfs_inode and the files were represented by
   a eventfs_file.

   In v6.7 the eventfs_file is removed. As all events have the same
   directory make up (sched_switch has an "enable", "id", "format", etc
   files), the handing of what files are underneath each leaf eventfs
   directory is moved back to the tracing subsystem via a callback.

   When an event is added to the eventfs, it registers an array of
   evenfs_entry's. These hold the names of the files and the callbacks
   to call when the file is referenced. The callback gets the name so
   that the same callback may be used by multiple files. The callback
   then supplies the filesystem_operations structure needed to create
   this file.

   This has brought the memory footprint of creating multiple eventfs
   instances down by 2 megs each!

 - User events now has persistent events that are not associated to a
   single processes. These are privileged events that hang around even
   if no process is attached to them

 - Clean up of seq_buf

   There's talk about using seq_buf more to replace strscpy() and
   friends. But this also requires some minor modifications of seq_buf
   to be able to do this

 - Expand instance ring buffers individually

   Currently if boot up creates an instance, and a trace event is
   enabled on that instance, the ring buffer for that instance and the
   top level ring buffer are expanded (1.4 MB per CPU). This wastes
   memory as this happens when nothing is using the top level instance

 - Other minor clean ups and fixes

* tag 'trace-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (34 commits)
  seq_buf: Export seq_buf_puts()
  seq_buf: Export seq_buf_putc()
  eventfs: Use simple_recursive_removal() to clean up dentries
  eventfs: Remove special processing of dput() of events directory
  eventfs: Delete eventfs_inode when the last dentry is freed
  eventfs: Hold eventfs_mutex when calling callback functions
  eventfs: Save ownership and mode
  eventfs: Test for ei->is_freed when accessing ei->dentry
  eventfs: Have a free_ei() that just frees the eventfs_inode
  eventfs: Remove "is_freed" union with rcu head
  eventfs: Fix kerneldoc of eventfs_remove_rec()
  tracing: Have the user copy of synthetic event address use correct context
  eventfs: Remove extra dget() in eventfs_create_events_dir()
  tracing: Have trace_event_file have ref counters
  seq_buf: Introduce DECLARE_SEQ_BUF and seq_buf_str()
  eventfs: Fix typo in eventfs_inode union comment
  eventfs: Fix WARN_ON() in create_file_dentry()
  powerpc: Remove initialisation of readpos
  tracing/histograms: Simplify last_cmd_set()
  seq_buf: fix a misleading comment
  ...
2023-11-03 07:41:18 -10:00
..
.gitignore selftests/user_events: add gitignore file 2023-10-05 14:22:46 -06:00
abi_test.c Tracing updates for v6.7: 2023-11-03 07:41:18 -10:00
config selftests: user_events: create test-specific Kconfig fragments 2023-09-11 17:06:48 -06:00
dyn_test.c selftests/user_events: Test persist flag cases 2023-10-03 22:29:43 -04:00
ftrace_test.c selftests/user_events: Fix to unmount tracefs when test created mount 2023-09-18 11:04:52 -06:00
Makefile selftests/user_events: Reenable build 2023-08-16 10:29:57 -06:00
perf_test.c selftests/user_events: Fix to unmount tracefs when test created mount 2023-09-18 11:04:52 -06:00
settings
user_events_selftests.h selftests/user_events: Fix to unmount tracefs when test created mount 2023-09-18 11:04:52 -06:00