Messages in this thread | | | Date | Fri, 22 Jun 2007 15:53:23 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [RFC PATCH 1/5 v2] Convert the RCU tasklet into a softirq |
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On Fri, Jun 22, 2007 at 02:20:52PM -0400, Steven Rostedt wrote: > I believe this was originally done by Dipankar Sarma. I pulled these > changes from the -rt kernel. > > For better preformance, RCU should use a softirq instead of a > tasklet. > > From: Dipankar Sarma <dipankar@in.ibm.com> > Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> Index: linux-2.6-test/include/linux/interrupt.h > =================================================================== > --- linux-2.6-test.orig/include/linux/interrupt.h > +++ linux-2.6-test/include/linux/interrupt.h > @@ -245,6 +245,9 @@ enum > #ifdef CONFIG_HIGH_RES_TIMERS > HRTIMER_SOFTIRQ, > #endif > + RCU_SOFTIRQ, /* Preferable RCU should always be the last softirq */ > + /* Entries after this are ignored in split softirq mode */ > + MAX_SOFTIRQ, > }; > > /* softirq mask and active fields moved to irq_cpustat_t in > Index: linux-2.6-test/kernel/rcupdate.c > =================================================================== > --- linux-2.6-test.orig/kernel/rcupdate.c > +++ linux-2.6-test/kernel/rcupdate.c > @@ -67,7 +67,6 @@ DEFINE_PER_CPU(struct rcu_data, rcu_data > DEFINE_PER_CPU(struct rcu_data, rcu_bh_data) = { 0L }; > > /* Fake initialization required by compiler */ > -static DEFINE_PER_CPU(struct tasklet_struct, rcu_tasklet) = {NULL}; > static int blimit = 10; > static int qhimark = 10000; > static int qlowmark = 100; > @@ -253,7 +252,7 @@ static void rcu_do_batch(struct rcu_data > if (!rdp->donelist) > rdp->donetail = &rdp->donelist; > else > - tasklet_schedule(&per_cpu(rcu_tasklet, rdp->cpu)); > + raise_softirq(RCU_SOFTIRQ); > } > > /* > @@ -405,7 +404,6 @@ static void rcu_offline_cpu(int cpu) > &per_cpu(rcu_bh_data, cpu)); > put_cpu_var(rcu_data); > put_cpu_var(rcu_bh_data); > - tasklet_kill_immediate(&per_cpu(rcu_tasklet, cpu), cpu); > } > > #else > @@ -417,7 +415,7 @@ static void rcu_offline_cpu(int cpu) > #endif > > /* > - * This does the RCU processing work from tasklet context. > + * This does the RCU processing work from softirq context. > */ > static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp, > struct rcu_data *rdp) > @@ -462,7 +460,7 @@ static void __rcu_process_callbacks(stru > rcu_do_batch(rdp); > } > > -static void rcu_process_callbacks(unsigned long unused) > +static void rcu_process_callbacks(struct softirq_action *unused) > { > __rcu_process_callbacks(&rcu_ctrlblk, &__get_cpu_var(rcu_data)); > __rcu_process_callbacks(&rcu_bh_ctrlblk, &__get_cpu_var(rcu_bh_data)); > @@ -526,7 +524,7 @@ void rcu_check_callbacks(int cpu, int us > rcu_bh_qsctr_inc(cpu); > } else if (!in_softirq()) > rcu_bh_qsctr_inc(cpu); > - tasklet_schedule(&per_cpu(rcu_tasklet, cpu)); > + raise_softirq(RCU_SOFTIRQ); > } > > static void rcu_init_percpu_data(int cpu, struct rcu_ctrlblk *rcp, > @@ -549,7 +547,7 @@ static void __devinit rcu_online_cpu(int > > rcu_init_percpu_data(cpu, &rcu_ctrlblk, rdp); > rcu_init_percpu_data(cpu, &rcu_bh_ctrlblk, bh_rdp); > - tasklet_init(&per_cpu(rcu_tasklet, cpu), rcu_process_callbacks, 0UL); > + open_softirq(RCU_SOFTIRQ, rcu_process_callbacks, NULL); > } > > static int __cpuinit rcu_cpu_notify(struct notifier_block *self, > > -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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