[RFC V2 PATCH 0/3] timer: patchset focus on del_timer_sync()

[Yong Zhang <yong.zhang0@gmail.com>]

From: Yong Zhang <yong.zhang@windriver.com>

This is inspired by http://lkml.org/lkml/2010/8/16/291
which catch a lockdep false positive on fake_timer_lock.
When I go into del_timer_sync(), but don't find anything
which prevent del_timer_sync() from using in softirq context,
and indeed it's been used in softirq for some timer(such as
__dst_free()).

Thus, tell others it can't be used in softirq context, and
teach lockdep about that. It's realized by patch-0002.

Your comments are very appreciated.

Thanks,
Yong

V2 <- V1
  Update patch 0001, the new version make try_to_del_timer_sync()
  safe on both hardirq context and UP. Thanks Oleg.

---
Yong Zhang (3):
      timer: make try_to_del_timer_sync() safe on both hardirq context and UP
      timer: del_timer_sync() can be used in softirq context
      timer: warn when del_timer_sync() used in hardirq context

 include/linux/timer.h |    4 ++--
 kernel/timer.c        |   20 +++++++++-----------
 2 files changed, 11 insertions(+), 13 deletions(-)