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| author | Oleg Nesterov <oleg@tv-sign.ru> | 2006-03-24 03:15:50 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-24 07:33:20 -0800 |
| commit | caa9ee771de3195ae85ac6f8cb550f53e9ecdd82 (patch) | |
| tree | 8aa692f337e071718e698baefc631b58b446beff /kernel | |
| parent | cba9f33d13a8ca3125b2a30abe2425ce562d8a83 (diff) | |
| download | lwn-caa9ee771de3195ae85ac6f8cb550f53e9ecdd82.tar.gz lwn-caa9ee771de3195ae85ac6f8cb550f53e9ecdd82.zip | |
[PATCH] rcu_process_callbacks: don't cli() while testing ->nxtlist
__rcu_process_callbacks() disables interrupts to protect itself from
call_rcu() which adds new entries to ->nxtlist.
However we can check "->nxtlist != NULL" with interrupts enabled, we can't
get "false positives" because call_rcu() can only change this condition
from 0 to 1.
Tested with rcutorture.ko.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Dipankar Sarma <dipankar@in.ibm.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcupdate.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c index 6df1559b1c02..13458bbaa1be 100644 --- a/kernel/rcupdate.c +++ b/kernel/rcupdate.c @@ -416,8 +416,8 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp, rdp->curtail = &rdp->curlist; } - local_irq_disable(); if (rdp->nxtlist && !rdp->curlist) { + local_irq_disable(); rdp->curlist = rdp->nxtlist; rdp->curtail = rdp->nxttail; rdp->nxtlist = NULL; @@ -442,9 +442,8 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp, rcu_start_batch(rcp); spin_unlock(&rcp->lock); } - } else { - local_irq_enable(); } + rcu_check_quiescent_state(rcp, rdp); if (rdp->donelist) rcu_do_batch(rdp); |