Commit c3077b5d authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

blk-mq: merge blk-softirq.c into blk-mq.c 



__blk_complete_request is only called from the blk-mq code, and
duplicates a lot of code from blk-mq.c.  Move it there to prepare
for better code sharing and simplifications.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDaniel Wagner <dwagner@suse.de>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 48778464

block/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -5,7 +5,7 @@ 


obj-$(CONFIG_BLOCK) := bio.o elevator.o blk-core.o blk-sysfs.o \

			blk-flush.o blk-settings.o blk-ioc.o blk-map.o \

			blk-exec.o blk-merge.o blk-softirq.o blk-timeout.o \

			blk-exec.o blk-merge.o blk-timeout.o \

			blk-lib.o blk-mq.o blk-mq-tag.o blk-stat.o \

			blk-mq-sysfs.o blk-mq-cpumap.o blk-mq-sched.o ioctl.o \

			genhd.o ioprio.o badblocks.o partitions/ blk-rq-qos.o

block/blk-mq.c

+135 −0
Original line number Diff line number Diff line
@@ -41,6 +41,8 @@ 
#include "blk-mq-sched.h"

#include "blk-rq-qos.h"



static DEFINE_PER_CPU(struct list_head, blk_cpu_done);



static void blk_mq_poll_stats_start(struct request_queue *q);

static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb);
@@ -574,6 +576,130 @@ void blk_mq_end_request(struct request *rq, blk_status_t error) 
}

EXPORT_SYMBOL(blk_mq_end_request);



/*

 * Softirq action handler - move entries to local list and loop over them

 * while passing them to the queue registered handler.

 */

static __latent_entropy void blk_done_softirq(struct softirq_action *h)

{

	struct list_head *cpu_list, local_list;



	local_irq_disable();

	cpu_list = this_cpu_ptr(&blk_cpu_done);

	list_replace_init(cpu_list, &local_list);

	local_irq_enable();



	while (!list_empty(&local_list)) {

		struct request *rq;



		rq = list_entry(local_list.next, struct request, ipi_list);

		list_del_init(&rq->ipi_list);

		rq->q->mq_ops->complete(rq);

	}

}



#ifdef CONFIG_SMP

static void trigger_softirq(void *data)

{

	struct request *rq = data;

	struct list_head *list;



	list = this_cpu_ptr(&blk_cpu_done);

	list_add_tail(&rq->ipi_list, list);



	if (list->next == &rq->ipi_list)

		raise_softirq_irqoff(BLOCK_SOFTIRQ);

}



/*

 * Setup and invoke a run of 'trigger_softirq' on the given cpu.

 */

static int raise_blk_irq(int cpu, struct request *rq)

{

	if (cpu_online(cpu)) {

		call_single_data_t *data = &rq->csd;



		data->func = trigger_softirq;

		data->info = rq;

		data->flags = 0;



		smp_call_function_single_async(cpu, data);

		return 0;

	}



	return 1;

}

#else /* CONFIG_SMP */

static int raise_blk_irq(int cpu, struct request *rq)

{

	return 1;

}

#endif



static int blk_softirq_cpu_dead(unsigned int cpu)

{

	/*

	 * If a CPU goes away, splice its entries to the current CPU

	 * and trigger a run of the softirq

	 */

	local_irq_disable();

	list_splice_init(&per_cpu(blk_cpu_done, cpu),

			 this_cpu_ptr(&blk_cpu_done));

	raise_softirq_irqoff(BLOCK_SOFTIRQ);

	local_irq_enable();



	return 0;

}



static void __blk_complete_request(struct request *req)

{

	struct request_queue *q = req->q;

	int cpu, ccpu = req->mq_ctx->cpu;

	unsigned long flags;

	bool shared = false;



	BUG_ON(!q->mq_ops->complete);



	local_irq_save(flags);

	cpu = smp_processor_id();



	/*

	 * Select completion CPU

	 */

	if (test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags) && ccpu != -1) {

		if (!test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags))

			shared = cpus_share_cache(cpu, ccpu);

	} else

		ccpu = cpu;



	/*

	 * If current CPU and requested CPU share a cache, run the softirq on

	 * the current CPU. One might concern this is just like

	 * QUEUE_FLAG_SAME_FORCE, but actually not. blk_complete_request() is

	 * running in interrupt handler, and currently I/O controller doesn't

	 * support multiple interrupts, so current CPU is unique actually. This

	 * avoids IPI sending from current CPU to the first CPU of a group.

	 */

	if (ccpu == cpu || shared) {

		struct list_head *list;

do_local:

		list = this_cpu_ptr(&blk_cpu_done);

		list_add_tail(&req->ipi_list, list);



		/*

		 * if the list only contains our just added request,

		 * signal a raise of the softirq. If there are already

		 * entries there, someone already raised the irq but it

		 * hasn't run yet.

		 */

		if (list->next == &req->ipi_list)

			raise_softirq_irqoff(BLOCK_SOFTIRQ);

	} else if (raise_blk_irq(ccpu, req))

		goto do_local;



	local_irq_restore(flags);

}



static void __blk_mq_complete_request_remote(void *data)

{

	struct request *rq = data;
@@ -3760,6 +3886,15 @@ EXPORT_SYMBOL(blk_mq_rq_cpu); 


static int __init blk_mq_init(void)

{

	int i;



	for_each_possible_cpu(i)

		INIT_LIST_HEAD(&per_cpu(blk_cpu_done, i));

	open_softirq(BLOCK_SOFTIRQ, blk_done_softirq);



	cpuhp_setup_state_nocalls(CPUHP_BLOCK_SOFTIRQ_DEAD,

				  "block/softirq:dead", NULL,

				  blk_softirq_cpu_dead);

	cpuhp_setup_state_multi(CPUHP_BLK_MQ_DEAD, "block/mq:dead", NULL,

				blk_mq_hctx_notify_dead);

	cpuhp_setup_state_multi(CPUHP_AP_BLK_MQ_ONLINE, "block/mq:online",

block/blk-softirq.c

deleted100644 → 0
+0 −156
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * Functions related to softirq rq completions

 */

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/bio.h>

#include <linux/blkdev.h>

#include <linux/interrupt.h>

#include <linux/cpu.h>

#include <linux/sched.h>

#include <linux/sched/topology.h>



#include "blk.h"



static DEFINE_PER_CPU(struct list_head, blk_cpu_done);



/*

 * Softirq action handler - move entries to local list and loop over them

 * while passing them to the queue registered handler.

 */

static __latent_entropy void blk_done_softirq(struct softirq_action *h)

{

	struct list_head *cpu_list, local_list;



	local_irq_disable();

	cpu_list = this_cpu_ptr(&blk_cpu_done);

	list_replace_init(cpu_list, &local_list);

	local_irq_enable();



	while (!list_empty(&local_list)) {

		struct request *rq;



		rq = list_entry(local_list.next, struct request, ipi_list);

		list_del_init(&rq->ipi_list);

		rq->q->mq_ops->complete(rq);

	}

}



#ifdef CONFIG_SMP

static void trigger_softirq(void *data)

{

	struct request *rq = data;

	struct list_head *list;



	list = this_cpu_ptr(&blk_cpu_done);

	list_add_tail(&rq->ipi_list, list);



	if (list->next == &rq->ipi_list)

		raise_softirq_irqoff(BLOCK_SOFTIRQ);

}



/*

 * Setup and invoke a run of 'trigger_softirq' on the given cpu.

 */

static int raise_blk_irq(int cpu, struct request *rq)

{

	if (cpu_online(cpu)) {

		call_single_data_t *data = &rq->csd;



		data->func = trigger_softirq;

		data->info = rq;

		data->flags = 0;



		smp_call_function_single_async(cpu, data);

		return 0;

	}



	return 1;

}

#else /* CONFIG_SMP */

static int raise_blk_irq(int cpu, struct request *rq)

{

	return 1;

}

#endif



static int blk_softirq_cpu_dead(unsigned int cpu)

{

	/*

	 * If a CPU goes away, splice its entries to the current CPU

	 * and trigger a run of the softirq

	 */

	local_irq_disable();

	list_splice_init(&per_cpu(blk_cpu_done, cpu),

			 this_cpu_ptr(&blk_cpu_done));

	raise_softirq_irqoff(BLOCK_SOFTIRQ);

	local_irq_enable();



	return 0;

}



void __blk_complete_request(struct request *req)

{

	struct request_queue *q = req->q;

	int cpu, ccpu = req->mq_ctx->cpu;

	unsigned long flags;

	bool shared = false;



	BUG_ON(!q->mq_ops->complete);



	local_irq_save(flags);

	cpu = smp_processor_id();



	/*

	 * Select completion CPU

	 */

	if (test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags) && ccpu != -1) {

		if (!test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags))

			shared = cpus_share_cache(cpu, ccpu);

	} else

		ccpu = cpu;



	/*

	 * If current CPU and requested CPU share a cache, run the softirq on

	 * the current CPU. One might concern this is just like

	 * QUEUE_FLAG_SAME_FORCE, but actually not. blk_complete_request() is

	 * running in interrupt handler, and currently I/O controller doesn't

	 * support multiple interrupts, so current CPU is unique actually. This

	 * avoids IPI sending from current CPU to the first CPU of a group.

	 */

	if (ccpu == cpu || shared) {

		struct list_head *list;

do_local:

		list = this_cpu_ptr(&blk_cpu_done);

		list_add_tail(&req->ipi_list, list);



		/*

		 * if the list only contains our just added request,

		 * signal a raise of the softirq. If there are already

		 * entries there, someone already raised the irq but it

		 * hasn't run yet.

		 */

		if (list->next == &req->ipi_list)

			raise_softirq_irqoff(BLOCK_SOFTIRQ);

	} else if (raise_blk_irq(ccpu, req))

		goto do_local;



	local_irq_restore(flags);

}



static __init int blk_softirq_init(void)

{

	int i;



	for_each_possible_cpu(i)

		INIT_LIST_HEAD(&per_cpu(blk_cpu_done, i));



	open_softirq(BLOCK_SOFTIRQ, blk_done_softirq);

	cpuhp_setup_state_nocalls(CPUHP_BLOCK_SOFTIRQ_DEAD,

				  "block/softirq:dead", NULL,

				  blk_softirq_cpu_dead);

	return 0;

}

subsys_initcall(blk_softirq_init);

include/linux/blkdev.h

+0 −1
Original line number Diff line number Diff line
@@ -1078,7 +1078,6 @@ void blk_steal_bios(struct bio_list *list, struct request *rq); 
extern bool blk_update_request(struct request *rq, blk_status_t error,

			       unsigned int nr_bytes);



extern void __blk_complete_request(struct request *);

extern void blk_abort_request(struct request *);



/*

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