1. 14 Apr, 2010 2 commits
    • Paul E. McKenney's avatar
      rcu: Add rcu_access_pointer and rcu_dereference_protected · b62730ba
      Paul E. McKenney authored
      This patch adds variants of rcu_dereference() that handle
      situations where the RCU-protected data structure cannot change,
      perhaps due to our holding the update-side lock, or where the
      RCU-protected pointer is only to be fetched, not dereferenced.
      These are needed due to some performance concerns with using
      rcu_dereference() where it is not required, aside from the need
      for lockdep/sparse checking.
      
      The new rcu_access_pointer() primitive is for the case where the
      pointer is be fetch and not dereferenced.  This primitive may be
      used without protection, RCU or otherwise, due to the fact that
      it uses ACCESS_ONCE().
      
      The new rcu_dereference_protected() primitive is for the case
      where updates are prevented, for example, due to holding the
      update-side lock.  This primitive does neither ACCESS_ONCE() nor
      smp_read_barrier_depends(), so can only be used when updates are
      somehow prevented.
      Suggested-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: laijs@cn.fujitsu.com
      Cc: dipankar@in.ibm.com
      Cc: mathieu.desnoyers@polymtl.ca
      Cc: josh@joshtriplett.org
      Cc: dvhltc@us.ibm.com
      Cc: niv@us.ibm.com
      Cc: peterz@infradead.org
      Cc: rostedt@goodmis.org
      Cc: Valdis.Kletnieks@vt.edu
      Cc: dhowells@redhat.com
      Cc: eric.dumazet@gmail.com
      LKML-Reference: <1270852752-25278-1-git-send-email-paulmck@linux.vnet.ibm.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      b62730ba
    • Linus Torvalds's avatar
      Merge branch 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6 · 2ba3abd8
      Linus Torvalds authored
      * 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
        PM / Hibernate: user.c, fix SNAPSHOT_SET_SWAP_AREA handling
      2ba3abd8
  2. 13 Apr, 2010 35 commits
  3. 12 Apr, 2010 3 commits