Commit 1d156646 authored by Tejun Heo's avatar Tejun Heo Committed by Jens Axboe
Browse files

blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTAT 



blkg_rwstat is now only used by bfq-iosched and blk-throtl when on
cgroup1.  Let's move it into its own files and gate it behind a config
option.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent f7331648

block/Kconfig

+4 −0
Original line number Diff line number Diff line
@@ -32,6 +32,9 @@ config BLK_RQ_ALLOC_TIME 
config BLK_SCSI_REQUEST

	bool



config BLK_CGROUP_RWSTAT

	bool



config BLK_DEV_BSG

	bool "Block layer SG support v4"

	default y
@@ -86,6 +89,7 @@ config BLK_DEV_ZONED 
config BLK_DEV_THROTTLING

	bool "Block layer bio throttling support"

	depends on BLK_CGROUP=y

	select BLK_CGROUP_RWSTAT

	---help---

	Block layer bio throttling support. It can be used to limit

	the IO rate to a device. IO rate policies are per cgroup and

block/Kconfig.iosched

+1 −0
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ config IOSCHED_BFQ 
config BFQ_GROUP_IOSCHED

       bool "BFQ hierarchical scheduling support"

       depends on IOSCHED_BFQ && BLK_CGROUP

       select BLK_CGROUP_RWSTAT

       ---help---



       Enable hierarchical scheduling in BFQ, using the blkio

block/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ obj-$(CONFIG_BLK_SCSI_REQUEST) += scsi_ioctl.o 
obj-$(CONFIG_BLK_DEV_BSG)	+= bsg.o

obj-$(CONFIG_BLK_DEV_BSGLIB)	+= bsg-lib.o

obj-$(CONFIG_BLK_CGROUP)	+= blk-cgroup.o

obj-$(CONFIG_BLK_CGROUP_RWSTAT)	+= blk-cgroup-rwstat.o

obj-$(CONFIG_BLK_DEV_THROTTLING)	+= blk-throttle.o

obj-$(CONFIG_BLK_CGROUP_IOLATENCY)	+= blk-iolatency.o

obj-$(CONFIG_BLK_CGROUP_IOCOST)	+= blk-iocost.o

block/bfq-iosched.h

+2 −0
Original line number Diff line number Diff line
@@ -10,6 +10,8 @@ 
#include <linux/hrtimer.h>

#include <linux/blk-cgroup.h>



#include "blk-cgroup-rwstat.h"



#define BFQ_IOPRIO_CLASSES	3

#define BFQ_CL_IDLE_TIMEOUT	(HZ/5)

block/blk-cgroup-rwstat.c

0 → 100644
+129 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0

 *

 * Legacy blkg rwstat helpers enabled by CONFIG_BLK_CGROUP_RWSTAT.

 * Do not use in new code.

 */

#include "blk-cgroup-rwstat.h"



int blkg_rwstat_init(struct blkg_rwstat *rwstat, gfp_t gfp)

{

	int i, ret;



	for (i = 0; i < BLKG_RWSTAT_NR; i++) {

		ret = percpu_counter_init(&rwstat->cpu_cnt[i], 0, gfp);

		if (ret) {

			while (--i >= 0)

				percpu_counter_destroy(&rwstat->cpu_cnt[i]);

			return ret;

		}

		atomic64_set(&rwstat->aux_cnt[i], 0);

	}

	return 0;

}

EXPORT_SYMBOL_GPL(blkg_rwstat_init);



void blkg_rwstat_exit(struct blkg_rwstat *rwstat)

{

	int i;



	for (i = 0; i < BLKG_RWSTAT_NR; i++)

		percpu_counter_destroy(&rwstat->cpu_cnt[i]);

}

EXPORT_SYMBOL_GPL(blkg_rwstat_exit);



/**

 * __blkg_prfill_rwstat - prfill helper for a blkg_rwstat

 * @sf: seq_file to print to

 * @pd: policy private data of interest

 * @rwstat: rwstat to print

 *

 * Print @rwstat to @sf for the device assocaited with @pd.

 */

u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,

			 const struct blkg_rwstat_sample *rwstat)

{

	static const char *rwstr[] = {

		[BLKG_RWSTAT_READ]	= "Read",

		[BLKG_RWSTAT_WRITE]	= "Write",

		[BLKG_RWSTAT_SYNC]	= "Sync",

		[BLKG_RWSTAT_ASYNC]	= "Async",

		[BLKG_RWSTAT_DISCARD]	= "Discard",

	};

	const char *dname = blkg_dev_name(pd->blkg);

	u64 v;

	int i;



	if (!dname)

		return 0;



	for (i = 0; i < BLKG_RWSTAT_NR; i++)

		seq_printf(sf, "%s %s %llu\n", dname, rwstr[i],

			   rwstat->cnt[i]);



	v = rwstat->cnt[BLKG_RWSTAT_READ] +

		rwstat->cnt[BLKG_RWSTAT_WRITE] +

		rwstat->cnt[BLKG_RWSTAT_DISCARD];

	seq_printf(sf, "%s Total %llu\n", dname, v);

	return v;

}

EXPORT_SYMBOL_GPL(__blkg_prfill_rwstat);



/**

 * blkg_prfill_rwstat - prfill callback for blkg_rwstat

 * @sf: seq_file to print to

 * @pd: policy private data of interest

 * @off: offset to the blkg_rwstat in @pd

 *

 * prfill callback for printing a blkg_rwstat.

 */

u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,

		       int off)

{

	struct blkg_rwstat_sample rwstat = { };



	blkg_rwstat_read((void *)pd + off, &rwstat);

	return __blkg_prfill_rwstat(sf, pd, &rwstat);

}

EXPORT_SYMBOL_GPL(blkg_prfill_rwstat);



/**

 * blkg_rwstat_recursive_sum - collect hierarchical blkg_rwstat

 * @blkg: blkg of interest

 * @pol: blkcg_policy which contains the blkg_rwstat

 * @off: offset to the blkg_rwstat in blkg_policy_data or @blkg

 * @sum: blkg_rwstat_sample structure containing the results

 *

 * Collect the blkg_rwstat specified by @blkg, @pol and @off and all its

 * online descendants and their aux counts.  The caller must be holding the

 * queue lock for online tests.

 *

 * If @pol is NULL, blkg_rwstat is at @off bytes into @blkg; otherwise, it

 * is at @off bytes into @blkg's blkg_policy_data of the policy.

 */

void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol,

		int off, struct blkg_rwstat_sample *sum)

{

	struct blkcg_gq *pos_blkg;

	struct cgroup_subsys_state *pos_css;

	unsigned int i;



	lockdep_assert_held(&blkg->q->queue_lock);



	rcu_read_lock();

	blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) {

		struct blkg_rwstat *rwstat;



		if (!pos_blkg->online)

			continue;



		if (pol)

			rwstat = (void *)blkg_to_pd(pos_blkg, pol) + off;

		else

			rwstat = (void *)pos_blkg + off;



		for (i = 0; i < BLKG_RWSTAT_NR; i++)

			sum->cnt[i] = blkg_rwstat_read_counter(rwstat, i);

	}

	rcu_read_unlock();

}

EXPORT_SYMBOL_GPL(blkg_rwstat_recursive_sum);