Skip to content

K
kernel_linux

OpenHarmony / kernel_linux
上一次同步 3 年多

通知 13
Star 8
Fork 2
K
kernel_linux
切换分支/标签
  1. 04 7月, 2006 2 次提交
    • I
      [PATCH] sched: cleanup, remove task_t, convert to struct task_struct · 36c8b586
      由 Ingo Molnar 提交于 
      cleanup: remove task_t and convert all the uses to struct task_struct. I
introduced it for the scheduler anno and it was a mistake.

Conversion was mostly scripted, the result was reviewed and all
secondary whitespace and style impact (if any) was fixed up by hand.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      36c8b586
    • I
      [PATCH] lockdep: better lock debugging · 9a11b49a
      由 Ingo Molnar 提交于 
      Generic lock debugging:

 - generalized lock debugging framework. For example, a bug in one lock
   subsystem turns off debugging in all lock subsystems.

 - got rid of the caller address passing (__IP__/__IP_DECL__/etc.) from
   the mutex/rtmutex debugging code: it caused way too much prototype
   hackery, and lockdep will give the same information anyway.

 - ability to do silent tests

 - check lock freeing in vfree too.

 - more finegrained debugging options, to allow distributions to
   turn off more expensive debugging features.

There's no separate 'held mutexes' list anymore - but there's a 'held locks'
stack within lockdep, which unifies deadlock detection across all lock
classes.  (this is independent of the lockdep validation stuff - lockdep first
checks whether we are holding a lock already)

Here are the current debugging options:

CONFIG_DEBUG_MUTEXES=y
CONFIG_DEBUG_LOCK_ALLOC=y

which do:

 config DEBUG_MUTEXES
          bool "Mutex debugging, basic checks"

 config DEBUG_LOCK_ALLOC
         bool "Detect incorrect freeing of live mutexes"
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      9a11b49a
  3. 01 7月, 2006 1 次提交
  5. 28 6月, 2006 2 次提交
  7. 27 6月, 2006 1 次提交
  9. 26 6月, 2006 4 次提交
  11. 23 6月, 2006 1 次提交
  13. 18 6月, 2006 1 次提交
  15. 01 5月, 2006 1 次提交
  17. 20 4月, 2006 1 次提交
  19. 11 4月, 2006 1 次提交
    • J
      [PATCH] splice: add direct fd <-> fd splicing support · b92ce558
      由 Jens Axboe 提交于 
      It's more efficient for sendfile() emulation. Basically we cache an
internal private pipe and just use that as the intermediate area for
pages. Direct splicing is not available from sys_splice(), it is only
meant to be used for sendfile() emulation.

Additional patch from Ingo Molnar to avoid the PIPE_BUFFERS loop at
exit for the normal fast path.
Signed-off-by: NJens Axboe <axboe@suse.de>
      b92ce558
  21. 01 4月, 2006 1 次提交
    • E
      [PATCH] task: RCU protect task->usage · 8c7904a0
      由 Eric W. Biederman 提交于 
      A big problem with rcu protected data structures that are also reference
counted is that you must jump through several hoops to increase the reference
count.  I think someone finally implemented atomic_inc_not_zero(&count) to
automate the common case.  Unfortunately this means you must special case the
rcu access case.

When data structures are only visible via rcu in a manner that is not
determined by the reference count on the object (i.e.  tasks are visible until
their zombies are reaped) there is a much simpler technique we can employ.
Simply delaying the decrement of the reference count until the rcu interval is
over.

What that means is that the proc code that looks up a task and later
wants to sleep can now do:

rcu_read_lock();
task = find_task_by_pid(some_pid);
if (task) {
	get_task_struct(task);
}
rcu_read_unlock();

The effect on the rest of the kernel is that put_task_struct becomes cheaper
and immediate, and in the case where the task has been reaped it frees the
task immediate instead of unnecessarily waiting an until the rcu interval is
over.

Cleanup of task_struct does not happen when its reference count drops to
zero, instead cleanup happens when release_task is called.  Tasks can only
be looked up via rcu before release_task is called.  All rcu protected
members of task_struct are freed by release_task.

Therefore we can move call_rcu from put_task_struct into release_task.  And
we can modify release_task to not immediately release the reference count
but instead have it call put_task_struct from the function it gives to
call_rcu.

The end result:

- get_task_struct is safe in an rcu context where we have just looked
  up the task.

- put_task_struct() simplifies into its old pre rcu self.

This reorganization also makes put_task_struct uncallable from modules as
it is not exported but it does not appear to be called from any modules so
this should not be an issue, and is trivially fixed.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      8c7904a0
  23. 29 3月, 2006 14 次提交
  25. 28 3月, 2006 2 次提交
  27. 23 3月, 2006 1 次提交
  29. 19 3月, 2006 1 次提交
  31. 21 2月, 2006 1 次提交
  33. 15 1月, 2006 2 次提交
  35. 12 1月, 2006 1 次提交
  37. 11 1月, 2006 2 次提交