| Message ID | 20240815171549.3260003-1-csander@purestorage.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | e68ac2b488495fa4d127d6105ce633849859957a |
| Headers | show |
| Series | [v2] softirq: remove parameter from action callback | expand |
On 8/15/24 11:15 AM, Caleb Sander Mateos wrote: > When softirq actions are called, they are passed a pointer to the entry > in the softirq_vec table containing the action's function pointer. This > pointer isn't very useful, as the action callback already knows what > function it is. And since each callback handles a specific softirq, the > callback also knows which softirq number is running. > > No softirq action callbacks actually use this parameter, so remove it > from the function pointer signature. This clarifies that softirq actions > are global routines and makes it slightly cheaper to call them. > > v2: use full 72 characters in commit description lines, add Reviewed-by No need to resend because of it, but the changelog bits go below the --- line, not in the commit message. Whoever applies can just take care of that.
On Thu, Aug 15, 2024 at 11:15:40AM -0600, Caleb Sander Mateos wrote: > When softirq actions are called, they are passed a pointer to the entry > in the softirq_vec table containing the action's function pointer. This > pointer isn't very useful, as the action callback already knows what > function it is. And since each callback handles a specific softirq, the > callback also knows which softirq number is running. > > No softirq action callbacks actually use this parameter, so remove it > from the function pointer signature. This clarifies that softirq actions > are global routines and makes it slightly cheaper to call them. > > v2: use full 72 characters in commit description lines, add Reviewed-by > > Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> > Reviewed-by: Jens Axboe <axboe@kernel.dk> For the RCU pieces: Reviewed-by: Paul E. McKenney <paulmck@kernel.org> > --- > block/blk-mq.c | 2 +- > include/linux/interrupt.h | 4 ++-- > kernel/rcu/tiny.c | 2 +- > kernel/rcu/tree.c | 2 +- > kernel/sched/fair.c | 2 +- > kernel/softirq.c | 15 +++++++-------- > kernel/time/hrtimer.c | 2 +- > kernel/time/timer.c | 2 +- > lib/irq_poll.c | 2 +- > net/core/dev.c | 4 ++-- > 10 files changed, 18 insertions(+), 19 deletions(-) > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index e3c3c0c21b55..aa28157b1aaf 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -1126,11 +1126,11 @@ static void blk_complete_reqs(struct llist_head *list) > > llist_for_each_entry_safe(rq, next, entry, ipi_list) > rq->q->mq_ops->complete(rq); > } > > -static __latent_entropy void blk_done_softirq(struct softirq_action *h) > +static __latent_entropy void blk_done_softirq(void) > { > blk_complete_reqs(this_cpu_ptr(&blk_cpu_done)); > } > > static int blk_softirq_cpu_dead(unsigned int cpu) > diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h > index 3f30c88e0b4c..694de61e0b38 100644 > --- a/include/linux/interrupt.h > +++ b/include/linux/interrupt.h > @@ -592,11 +592,11 @@ extern const char * const softirq_to_name[NR_SOFTIRQS]; > * asm/hardirq.h to get better cache usage. KAO > */ > > struct softirq_action > { > - void (*action)(struct softirq_action *); > + void (*action)(void); > }; > > asmlinkage void do_softirq(void); > asmlinkage void __do_softirq(void); > > @@ -607,11 +607,11 @@ static inline void do_softirq_post_smp_call_flush(unsigned int unused) > { > do_softirq(); > } > #endif > > -extern void open_softirq(int nr, void (*action)(struct softirq_action *)); > +extern void open_softirq(int nr, void (*action)(void)); > extern void softirq_init(void); > extern void __raise_softirq_irqoff(unsigned int nr); > > extern void raise_softirq_irqoff(unsigned int nr); > extern void raise_softirq(unsigned int nr); > diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c > index 4402d6f5f857..b3b3ce34df63 100644 > --- a/kernel/rcu/tiny.c > +++ b/kernel/rcu/tiny.c > @@ -103,11 +103,11 @@ static inline bool rcu_reclaim_tiny(struct rcu_head *head) > rcu_lock_release(&rcu_callback_map); > return false; > } > > /* Invoke the RCU callbacks whose grace period has elapsed. */ > -static __latent_entropy void rcu_process_callbacks(struct softirq_action *unused) > +static __latent_entropy void rcu_process_callbacks(void) > { > struct rcu_head *next, *list; > unsigned long flags; > > /* Move the ready-to-invoke callbacks to a local list. */ > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > index e641cc681901..93bd665637c0 100644 > --- a/kernel/rcu/tree.c > +++ b/kernel/rcu/tree.c > @@ -2853,11 +2853,11 @@ static __latent_entropy void rcu_core(void) > // If strict GPs, schedule an RCU reader in a clean environment. > if (IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD)) > queue_work_on(rdp->cpu, rcu_gp_wq, &rdp->strict_work); > } > > -static void rcu_core_si(struct softirq_action *h) > +static void rcu_core_si(void) > { > rcu_core(); > } > > static void rcu_wake_cond(struct task_struct *t, int status) > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index 9057584ec06d..8dc9385f6da4 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -12481,11 +12481,11 @@ static int sched_balance_newidle(struct rq *this_rq, struct rq_flags *rf) > * - directly from the local scheduler_tick() for periodic load balancing > * > * - indirectly from a remote scheduler_tick() for NOHZ idle balancing > * through the SMP cross-call nohz_csd_func() > */ > -static __latent_entropy void sched_balance_softirq(struct softirq_action *h) > +static __latent_entropy void sched_balance_softirq(void) > { > struct rq *this_rq = this_rq(); > enum cpu_idle_type idle = this_rq->idle_balance; > /* > * If this CPU has a pending NOHZ_BALANCE_KICK, then do the > diff --git a/kernel/softirq.c b/kernel/softirq.c > index 02582017759a..d082e7840f88 100644 > --- a/kernel/softirq.c > +++ b/kernel/softirq.c > @@ -549,11 +549,11 @@ static void handle_softirqs(bool ksirqd) > prev_count = preempt_count(); > > kstat_incr_softirqs_this_cpu(vec_nr); > > trace_softirq_entry(vec_nr); > - h->action(h); > + h->action(); > trace_softirq_exit(vec_nr); > if (unlikely(prev_count != preempt_count())) { > pr_err("huh, entered softirq %u %s %p with preempt_count %08x, exited with %08x?\n", > vec_nr, softirq_to_name[vec_nr], h->action, > prev_count, preempt_count()); > @@ -698,11 +698,11 @@ void __raise_softirq_irqoff(unsigned int nr) > lockdep_assert_irqs_disabled(); > trace_softirq_raise(nr); > or_softirq_pending(1UL << nr); > } > > -void open_softirq(int nr, void (*action)(struct softirq_action *)) > +void open_softirq(int nr, void (*action)(void)) > { > softirq_vec[nr].action = action; > } > > /* > @@ -758,12 +758,11 @@ static bool tasklet_clear_sched(struct tasklet_struct *t) > t->use_callback ? (void *)t->callback : (void *)t->func); > > return false; > } > > -static void tasklet_action_common(struct softirq_action *a, > - struct tasklet_head *tl_head, > +static void tasklet_action_common(struct tasklet_head *tl_head, > unsigned int softirq_nr) > { > struct tasklet_struct *list; > > local_irq_disable(); > @@ -803,20 +802,20 @@ static void tasklet_action_common(struct softirq_action *a, > __raise_softirq_irqoff(softirq_nr); > local_irq_enable(); > } > } > > -static __latent_entropy void tasklet_action(struct softirq_action *a) > +static __latent_entropy void tasklet_action(void) > { > workqueue_softirq_action(false); > - tasklet_action_common(a, this_cpu_ptr(&tasklet_vec), TASKLET_SOFTIRQ); > + tasklet_action_common(this_cpu_ptr(&tasklet_vec), TASKLET_SOFTIRQ); > } > > -static __latent_entropy void tasklet_hi_action(struct softirq_action *a) > +static __latent_entropy void tasklet_hi_action(void) > { > workqueue_softirq_action(true); > - tasklet_action_common(a, this_cpu_ptr(&tasklet_hi_vec), HI_SOFTIRQ); > + tasklet_action_common(this_cpu_ptr(&tasklet_hi_vec), HI_SOFTIRQ); > } > > void tasklet_setup(struct tasklet_struct *t, > void (*callback)(struct tasklet_struct *)) > { > diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c > index b8ee320208d4..836157e09e25 100644 > --- a/kernel/time/hrtimer.c > +++ b/kernel/time/hrtimer.c > @@ -1755,11 +1755,11 @@ static void __hrtimer_run_queues(struct hrtimer_cpu_base *cpu_base, ktime_t now, > hrtimer_sync_wait_running(cpu_base, flags); > } > } > } > > -static __latent_entropy void hrtimer_run_softirq(struct softirq_action *h) > +static __latent_entropy void hrtimer_run_softirq(void) > { > struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases); > unsigned long flags; > ktime_t now; > > diff --git a/kernel/time/timer.c b/kernel/time/timer.c > index 64b0d8a0aa0f..760bbeb1f331 100644 > --- a/kernel/time/timer.c > +++ b/kernel/time/timer.c > @@ -2438,11 +2438,11 @@ static void run_timer_base(int index) > } > > /* > * This function runs timers and the timer-tq in bottom half context. > */ > -static __latent_entropy void run_timer_softirq(struct softirq_action *h) > +static __latent_entropy void run_timer_softirq(void) > { > run_timer_base(BASE_LOCAL); > if (IS_ENABLED(CONFIG_NO_HZ_COMMON)) { > run_timer_base(BASE_GLOBAL); > run_timer_base(BASE_DEF); > diff --git a/lib/irq_poll.c b/lib/irq_poll.c > index 2d5329a42105..08b242bbdbdf 100644 > --- a/lib/irq_poll.c > +++ b/lib/irq_poll.c > @@ -73,11 +73,11 @@ void irq_poll_complete(struct irq_poll *iop) > __irq_poll_complete(iop); > local_irq_restore(flags); > } > EXPORT_SYMBOL(irq_poll_complete); > > -static void __latent_entropy irq_poll_softirq(struct softirq_action *h) > +static void __latent_entropy irq_poll_softirq(void) > { > struct list_head *list = this_cpu_ptr(&blk_cpu_iopoll); > int rearm = 0, budget = irq_poll_budget; > unsigned long start_time = jiffies; > > diff --git a/net/core/dev.c b/net/core/dev.c > index 751d9b70e6ad..3ac02b0ca29e 100644 > --- a/net/core/dev.c > +++ b/net/core/dev.c > @@ -5246,11 +5246,11 @@ int netif_rx(struct sk_buff *skb) > local_bh_enable(); > return ret; > } > EXPORT_SYMBOL(netif_rx); > > -static __latent_entropy void net_tx_action(struct softirq_action *h) > +static __latent_entropy void net_tx_action(void) > { > struct softnet_data *sd = this_cpu_ptr(&softnet_data); > > if (sd->completion_queue) { > struct sk_buff *clist; > @@ -6919,11 +6919,11 @@ static int napi_threaded_poll(void *data) > napi_threaded_poll_loop(napi); > > return 0; > } > > -static __latent_entropy void net_rx_action(struct softirq_action *h) > +static __latent_entropy void net_rx_action(void) > { > struct softnet_data *sd = this_cpu_ptr(&softnet_data); > unsigned long time_limit = jiffies + > usecs_to_jiffies(READ_ONCE(net_hotdata.netdev_budget_usecs)); > struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx; > -- > 2.45.2 >
diff --git a/block/blk-mq.c b/block/blk-mq.c index e3c3c0c21b55..aa28157b1aaf 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1126,11 +1126,11 @@ static void blk_complete_reqs(struct llist_head *list) llist_for_each_entry_safe(rq, next, entry, ipi_list) rq->q->mq_ops->complete(rq); } -static __latent_entropy void blk_done_softirq(struct softirq_action *h) +static __latent_entropy void blk_done_softirq(void) { blk_complete_reqs(this_cpu_ptr(&blk_cpu_done)); } static int blk_softirq_cpu_dead(unsigned int cpu) diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 3f30c88e0b4c..694de61e0b38 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -592,11 +592,11 @@ extern const char * const softirq_to_name[NR_SOFTIRQS]; * asm/hardirq.h to get better cache usage. KAO */ struct softirq_action { - void (*action)(struct softirq_action *); + void (*action)(void); }; asmlinkage void do_softirq(void); asmlinkage void __do_softirq(void); @@ -607,11 +607,11 @@ static inline void do_softirq_post_smp_call_flush(unsigned int unused) { do_softirq(); } #endif -extern void open_softirq(int nr, void (*action)(struct softirq_action *)); +extern void open_softirq(int nr, void (*action)(void)); extern void softirq_init(void); extern void __raise_softirq_irqoff(unsigned int nr); extern void raise_softirq_irqoff(unsigned int nr); extern void raise_softirq(unsigned int nr); diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c index 4402d6f5f857..b3b3ce34df63 100644 --- a/kernel/rcu/tiny.c +++ b/kernel/rcu/tiny.c @@ -103,11 +103,11 @@ static inline bool rcu_reclaim_tiny(struct rcu_head *head) rcu_lock_release(&rcu_callback_map); return false; } /* Invoke the RCU callbacks whose grace period has elapsed. */ -static __latent_entropy void rcu_process_callbacks(struct softirq_action *unused) +static __latent_entropy void rcu_process_callbacks(void) { struct rcu_head *next, *list; unsigned long flags; /* Move the ready-to-invoke callbacks to a local list. */ diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index e641cc681901..93bd665637c0 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2853,11 +2853,11 @@ static __latent_entropy void rcu_core(void) // If strict GPs, schedule an RCU reader in a clean environment. if (IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD)) queue_work_on(rdp->cpu, rcu_gp_wq, &rdp->strict_work); } -static void rcu_core_si(struct softirq_action *h) +static void rcu_core_si(void) { rcu_core(); } static void rcu_wake_cond(struct task_struct *t, int status) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 9057584ec06d..8dc9385f6da4 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -12481,11 +12481,11 @@ static int sched_balance_newidle(struct rq *this_rq, struct rq_flags *rf) * - directly from the local scheduler_tick() for periodic load balancing * * - indirectly from a remote scheduler_tick() for NOHZ idle balancing * through the SMP cross-call nohz_csd_func() */ -static __latent_entropy void sched_balance_softirq(struct softirq_action *h) +static __latent_entropy void sched_balance_softirq(void) { struct rq *this_rq = this_rq(); enum cpu_idle_type idle = this_rq->idle_balance; /* * If this CPU has a pending NOHZ_BALANCE_KICK, then do the diff --git a/kernel/softirq.c b/kernel/softirq.c index 02582017759a..d082e7840f88 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -549,11 +549,11 @@ static void handle_softirqs(bool ksirqd) prev_count = preempt_count(); kstat_incr_softirqs_this_cpu(vec_nr); trace_softirq_entry(vec_nr); - h->action(h); + h->action(); trace_softirq_exit(vec_nr); if (unlikely(prev_count != preempt_count())) { pr_err("huh, entered softirq %u %s %p with preempt_count %08x, exited with %08x?\n", vec_nr, softirq_to_name[vec_nr], h->action, prev_count, preempt_count()); @@ -698,11 +698,11 @@ void __raise_softirq_irqoff(unsigned int nr) lockdep_assert_irqs_disabled(); trace_softirq_raise(nr); or_softirq_pending(1UL << nr); } -void open_softirq(int nr, void (*action)(struct softirq_action *)) +void open_softirq(int nr, void (*action)(void)) { softirq_vec[nr].action = action; } /* @@ -758,12 +758,11 @@ static bool tasklet_clear_sched(struct tasklet_struct *t) t->use_callback ? (void *)t->callback : (void *)t->func); return false; } -static void tasklet_action_common(struct softirq_action *a, - struct tasklet_head *tl_head, +static void tasklet_action_common(struct tasklet_head *tl_head, unsigned int softirq_nr) { struct tasklet_struct *list; local_irq_disable(); @@ -803,20 +802,20 @@ static void tasklet_action_common(struct softirq_action *a, __raise_softirq_irqoff(softirq_nr); local_irq_enable(); } } -static __latent_entropy void tasklet_action(struct softirq_action *a) +static __latent_entropy void tasklet_action(void) { workqueue_softirq_action(false); - tasklet_action_common(a, this_cpu_ptr(&tasklet_vec), TASKLET_SOFTIRQ); + tasklet_action_common(this_cpu_ptr(&tasklet_vec), TASKLET_SOFTIRQ); } -static __latent_entropy void tasklet_hi_action(struct softirq_action *a) +static __latent_entropy void tasklet_hi_action(void) { workqueue_softirq_action(true); - tasklet_action_common(a, this_cpu_ptr(&tasklet_hi_vec), HI_SOFTIRQ); + tasklet_action_common(this_cpu_ptr(&tasklet_hi_vec), HI_SOFTIRQ); } void tasklet_setup(struct tasklet_struct *t, void (*callback)(struct tasklet_struct *)) { diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index b8ee320208d4..836157e09e25 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -1755,11 +1755,11 @@ static void __hrtimer_run_queues(struct hrtimer_cpu_base *cpu_base, ktime_t now, hrtimer_sync_wait_running(cpu_base, flags); } } } -static __latent_entropy void hrtimer_run_softirq(struct softirq_action *h) +static __latent_entropy void hrtimer_run_softirq(void) { struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases); unsigned long flags; ktime_t now; diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 64b0d8a0aa0f..760bbeb1f331 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -2438,11 +2438,11 @@ static void run_timer_base(int index) } /* * This function runs timers and the timer-tq in bottom half context. */ -static __latent_entropy void run_timer_softirq(struct softirq_action *h) +static __latent_entropy void run_timer_softirq(void) { run_timer_base(BASE_LOCAL); if (IS_ENABLED(CONFIG_NO_HZ_COMMON)) { run_timer_base(BASE_GLOBAL); run_timer_base(BASE_DEF); diff --git a/lib/irq_poll.c b/lib/irq_poll.c index 2d5329a42105..08b242bbdbdf 100644 --- a/lib/irq_poll.c +++ b/lib/irq_poll.c @@ -73,11 +73,11 @@ void irq_poll_complete(struct irq_poll *iop) __irq_poll_complete(iop); local_irq_restore(flags); } EXPORT_SYMBOL(irq_poll_complete); -static void __latent_entropy irq_poll_softirq(struct softirq_action *h) +static void __latent_entropy irq_poll_softirq(void) { struct list_head *list = this_cpu_ptr(&blk_cpu_iopoll); int rearm = 0, budget = irq_poll_budget; unsigned long start_time = jiffies; diff --git a/net/core/dev.c b/net/core/dev.c index 751d9b70e6ad..3ac02b0ca29e 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5246,11 +5246,11 @@ int netif_rx(struct sk_buff *skb) local_bh_enable(); return ret; } EXPORT_SYMBOL(netif_rx); -static __latent_entropy void net_tx_action(struct softirq_action *h) +static __latent_entropy void net_tx_action(void) { struct softnet_data *sd = this_cpu_ptr(&softnet_data); if (sd->completion_queue) { struct sk_buff *clist; @@ -6919,11 +6919,11 @@ static int napi_threaded_poll(void *data) napi_threaded_poll_loop(napi); return 0; } -static __latent_entropy void net_rx_action(struct softirq_action *h) +static __latent_entropy void net_rx_action(void) { struct softnet_data *sd = this_cpu_ptr(&softnet_data); unsigned long time_limit = jiffies + usecs_to_jiffies(READ_ONCE(net_hotdata.netdev_budget_usecs)); struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx;