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author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-15 13:59:31 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-15 13:59:31 -0700 |
commit | 64fd52a52077d3cd5a778ca031c0aaecf885eaa6 (patch) | |
tree | 00d72f4aac587eeeff89b8af369250725bf83c6a /kernel/rcuclassic.c | |
parent | fe1a6875fcaaac2041945008a9875d2c07be1d9b (diff) | |
parent | 6c9fcaf2eec1b9f85226a694230dd957dd7926b3 (diff) |
Merge branch 'core/rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core/rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (23 commits)
rcu classic: update qlen when cpu offline
rcu: make rcutorture even more vicious: invoke RCU readers from irq handlers (timers)
rcu: make quiescent rcutorture less power-hungry
rcu, rcutorture: make quiescent rcutorture less power-hungry
rcu: make rcutorture more vicious: reinstate boot-time testing
rcu: make rcutorture more vicious: add stutter feature
rcutorture: WARN_ON_ONCE(1) when detecting an error
rcu: remove unused field struct rcu_data::rcu_tasklet
Revert "prohibit rcutorture from being compiled into the kernel"
rcu: fix nf_conntrack_helper.c build bug
rculist.h: fix include in net/netfilter/nf_conntrack_netlink.c
rcu: remove duplicated include in kernel/rcupreempt.c
rcu: remove duplicated include in kernel/rcupreempt_trace.c
RCU, rculist.h: fix list iterators
rcu: fix rcu_try_flip_waitack_needed() to prevent grace-period stall
rculist.h: use the rcu API
rcu: split list.h and move rcu-protected lists into rculist.h
sched: 1Q08 RCU doc update, add call_rcu_sched()
rcu: add call_rcu_sched() and friends to rcutorture
rcu: add rcu_barrier_sched() and rcu_barrier_bh()
...
Diffstat (limited to 'kernel/rcuclassic.c')
-rw-r--r-- | kernel/rcuclassic.c | 34 |
1 files changed, 33 insertions, 1 deletions
diff --git a/kernel/rcuclassic.c b/kernel/rcuclassic.c index 65c0906080e..16eeeaa9d61 100644 --- a/kernel/rcuclassic.c +++ b/kernel/rcuclassic.c @@ -387,6 +387,10 @@ static void __rcu_offline_cpu(struct rcu_data *this_rdp, rcu_move_batch(this_rdp, rdp->donelist, rdp->donetail); rcu_move_batch(this_rdp, rdp->curlist, rdp->curtail); rcu_move_batch(this_rdp, rdp->nxtlist, rdp->nxttail); + + local_irq_disable(); + this_rdp->qlen += rdp->qlen; + local_irq_enable(); } static void rcu_offline_cpu(int cpu) @@ -516,10 +520,38 @@ void rcu_check_callbacks(int cpu, int user) if (user || (idle_cpu(cpu) && !in_softirq() && hardirq_count() <= (1 << HARDIRQ_SHIFT))) { + + /* + * Get here if this CPU took its interrupt from user + * mode or from the idle loop, and if this is not a + * nested interrupt. In this case, the CPU is in + * a quiescent state, so count it. + * + * Also do a memory barrier. This is needed to handle + * the case where writes from a preempt-disable section + * of code get reordered into schedule() by this CPU's + * write buffer. The memory barrier makes sure that + * the rcu_qsctr_inc() and rcu_bh_qsctr_inc() are see + * by other CPUs to happen after any such write. + */ + + smp_mb(); /* See above block comment. */ rcu_qsctr_inc(cpu); rcu_bh_qsctr_inc(cpu); - } else if (!in_softirq()) + + } else if (!in_softirq()) { + + /* + * Get here if this CPU did not take its interrupt from + * softirq, in other words, if it is not interrupting + * a rcu_bh read-side critical section. This is an _bh + * critical section, so count it. The memory barrier + * is needed for the same reason as is the above one. + */ + + smp_mb(); /* See above block comment. */ rcu_bh_qsctr_inc(cpu); + } raise_rcu_softirq(); } |