commit c82199061009d1561e31e17fca5e47a87cb7ff4c
author Eric Dumazet <edumazet@google.com> Fri Aug 28 19:42:30 2015 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> Sat Sep 05 13:46:58 2015 -0700
tree 547ec8ef61b4d70c57ff478d9d1de4853c373d92
parent f377ea88b862bf7151be96d276f4cb740f8e1c41

task_work: remove fifo ordering guarantee

In commit f341861fb0b ("task_work: add a scheduling point in
task_work_run()") I fixed a latency problem adding a cond_resched()
call.

Later, commit ac3d0da8f329 added yet another loop to reverse a list,
bringing back the latency spike :

I've seen in some cases this loop taking 275 ms, if for example a
process with 2,000,000 files is killed.

We could add yet another cond_resched() in the reverse loop, or we
can simply remove the reversal, as I do not think anything
would depend on order of task_work_add() submitted works.

Fixes: ac3d0da8f329 ("task_work: Make task_work_add() lockless")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Maciej Żenczykowski <maze@google.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>