Messages in this thread Patch in this message | | | From | Pranith Kumar <> | Subject | [PATCH 06/16] rcu: Clear gp_flags only when actually starting new gp | Date | Wed, 23 Jul 2014 01:09:43 -0400 |
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We are clearing the gp_flags before we check if a grace period is in progress. If a grace period is in progress, we return after incorrectly clearing the gp_flags. The code comments say that this is highly unlikely, but just to be safe this commit moves the clearing of gp_flags to after the check for grace period in progress.
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> --- kernel/rcu/tree.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 044946e..b14cecd 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1605,7 +1605,6 @@ static int rcu_gp_init(struct rcu_state *rsp) raw_spin_unlock_irq(&rnp->lock); return 0; } - ACCESS_ONCE(rsp->gp_flags) = 0; /* Clear all flags: New grace period. */ if (WARN_ON_ONCE(rcu_gp_in_progress(rsp))) { /* @@ -1616,6 +1615,8 @@ static int rcu_gp_init(struct rcu_state *rsp) return 0; } + ACCESS_ONCE(rsp->gp_flags) = 0; /* Clear all flags: New grace period. */ + /* Advance to a new grace period and initialize state. */ record_gp_stall_check_time(rsp); /* Record GP times before starting GP, hence smp_store_release(). */ -- 2.0.0.rc2
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