diff options
| author | Manfred Spraul <manfred@colorfullife.com> | 2005-01-04 05:31:02 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-01-04 05:31:02 -0800 |
| commit | 17b3fed12daae4af3b970beac31a182dc6cee044 (patch) | |
| tree | fe7f40fde16aa74c85a512bf9e789b49e44a5735 /kernel/rcupdate.c | |
| parent | 2f803905de112869f6f45ba52bd266254053a912 (diff) | |
[PATCH] rcu: simplify quiescent state detection
Based on an initial patch from Oleg Nesterov <oleg@tv-sign.ru>
rcu_data.last_qsctr is not needed. Actually, not even a counter is needed,
just a flag that indicates that there was a quiescent state.
Signed-Off-By: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/rcupdate.c')
| -rw-r--r-- | kernel/rcupdate.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c index ebe7e5d96b35..f0ae3c3c013e 100644 --- a/kernel/rcupdate.c +++ b/kernel/rcupdate.c @@ -219,9 +219,9 @@ static void rcu_check_quiescent_state(struct rcu_ctrlblk *rcp, struct rcu_state *rsp, struct rcu_data *rdp) { if (rdp->quiescbatch != rcp->cur) { - /* new grace period: record qsctr value. */ + /* start new grace period: */ rdp->qs_pending = 1; - rdp->last_qsctr = rdp->qsctr; + rdp->passed_quiesc = 0; rdp->quiescbatch = rcp->cur; return; } @@ -234,11 +234,10 @@ static void rcu_check_quiescent_state(struct rcu_ctrlblk *rcp, return; /* - * Races with local timer interrupt - in the worst case - * we may miss one quiescent state of that CPU. That is - * tolerable. So no need to disable interrupts. + * Was there a quiescent state since the beginning of the grace + * period? If no, then exit and wait for the next call. */ - if (rdp->qsctr == rdp->last_qsctr) + if (!rdp->passed_quiesc) return; rdp->qs_pending = 0; |