diff options
| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2010-01-04 15:09:09 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2010-01-13 09:06:05 +0100 |
| commit | 46a1e34eda805501a8b32f26394faa435149f6d1 (patch) | |
| tree | 56359434e348fce6ffc8701fb4948dee1cb4c91f /kernel/rcutree.h | |
| parent | 45f014c52eef022873b19d6a20eb0ec9668f2b09 (diff) | |
| download | lwn-46a1e34eda805501a8b32f26394faa435149f6d1.tar.gz lwn-46a1e34eda805501a8b32f26394faa435149f6d1.zip | |
rcu: Make force_quiescent_state() start grace period if needed
Grace periods cannot be started while force_quiescent_state() is
active. This is OK in that the affected CPUs will try again
later, but it does induce needless grace-period delays. This
patch causes rcu_start_gp() to record a failed attempt to start
a grace period. When force_quiescent_state() prepares to return,
it then starts the grace period if there was such a failed
attempt.
Signed-off-by: Paul 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
LKML-Reference: <12626465501854-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/rcutree.h')
| -rw-r--r-- | kernel/rcutree.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/rcutree.h b/kernel/rcutree.h index edb6fae0fa94..bd5d78ad1c48 100644 --- a/kernel/rcutree.h +++ b/kernel/rcutree.h @@ -278,6 +278,11 @@ struct rcu_state { /* Force QS state. */ u8 fqs_active; /* force_quiescent_state() */ /* is running. */ + u8 fqs_need_gp; /* A CPU was prevented from */ + /* starting a new grace */ + /* period because */ + /* force_quiescent_state() */ + /* was running. */ long gpnum; /* Current gp number. */ long completed; /* # of last completed gp. */ |