blkio: Some debugging aids for CFQ (2868ef7b) · Commits · 戴 / test

block/Kconfig

+9 −0

Original line number	Diff line number	Diff line
		@@ -90,6 +90,15 @@ config BLK_CGROUP
		control disk bandwidth allocation (proportional time slice allocation)
		to such task groups.

		config DEBUG_BLK_CGROUP
		bool
		depends on BLK_CGROUP
		default n
		---help---
		Enable some debugging help. Currently it stores the cgroup path
		in the blk group which can be used by cfq for tracing various
		group related activity.

		endif # BLOCK

		config BLOCK_COMPAT

block/Kconfig.iosched

+9 −0

Original line number	Diff line number	Diff line
		@@ -40,6 +40,15 @@ config CFQ_GROUP_IOSCHED
		---help---
		Enable group IO scheduling in CFQ.

		config DEBUG_CFQ_IOSCHED
		bool "Debug CFQ Scheduling"
		depends on CFQ_GROUP_IOSCHED
		select DEBUG_BLK_CGROUP
		default n
		---help---
		Enable CFQ IO scheduling debugging in CFQ. Currently it makes
		blktrace output more verbose.

		choice
		prompt "Default I/O scheduler"
		default DEFAULT_CFQ

block/blk-cgroup.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -33,6 +33,10 @@ void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
		blkg->blkcg_id = css_id(&blkcg->css);
		hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list);
		spin_unlock_irqrestore(&blkcg->lock, flags);
		#ifdef CONFIG_DEBUG_BLK_CGROUP
		/* Need to take css reference ? */
		cgroup_path(blkcg->css.cgroup, blkg->path, sizeof(blkg->path));
		#endif
		}

		static void __blkiocg_del_blkio_group(struct blkio_group *blkg)

block/blk-cgroup.h

+13 −0

Original line number	Diff line number	Diff line
		@@ -27,12 +27,25 @@ struct blkio_group {
		void *key;
		struct hlist_node blkcg_node;
		unsigned short blkcg_id;
		#ifdef CONFIG_DEBUG_BLK_CGROUP
		/* Store cgroup path */
		char path[128];
		#endif
		};

		#define BLKIO_WEIGHT_MIN 100
		#define BLKIO_WEIGHT_MAX 1000
		#define BLKIO_WEIGHT_DEFAULT 500

		#ifdef CONFIG_DEBUG_BLK_CGROUP
		static inline char blkg_path(struct blkio_group blkg)
		{
		return blkg->path;
		}
		#else
		static inline char blkg_path(struct blkio_group blkg) { return NULL; }
		#endif

		#ifdef CONFIG_BLK_CGROUP
		extern struct blkio_cgroup blkio_root_cgroup;
		extern struct blkio_cgroup cgroup_to_blkio_cgroup(struct cgroup cgroup);

block/cfq-iosched.c

+18 −1

Original line number	Diff line number	Diff line
		@@ -341,8 +341,21 @@ CFQ_CFQQ_FNS(coop);
		CFQ_CFQQ_FNS(deep);
		#undef CFQ_CFQQ_FNS

		#ifdef CONFIG_DEBUG_CFQ_IOSCHED
		#define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \
		blk_add_trace_msg((cfqd)->queue, "cfq%d%c %s " fmt, (cfqq)->pid, \
		cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \
		blkg_path(&(cfqq)->cfqg->blkg), ##args);

		#define cfq_log_cfqg(cfqd, cfqg, fmt, args...) \
		blk_add_trace_msg((cfqd)->queue, "%s " fmt, \
		blkg_path(&(cfqg)->blkg), ##args); \

		#else
		#define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \
		blk_add_trace_msg((cfqd)->queue, "cfq%d " fmt, (cfqq)->pid, ##args)
		#define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do {} while (0);
		#endif
		#define cfq_log(cfqd, fmt, args...) \
		blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args)

		@@ -832,6 +845,7 @@ cfq_group_service_tree_del(struct cfq_data cfqd, struct cfq_group cfqg)
		if (cfqg->nr_cfqq)
		return;

		cfq_log_cfqg(cfqd, cfqg, "del_from_rr group");
		cfqg->on_st = false;
		cfqd->nr_groups--;
		st->total_weight -= cfqg->weight;
		@@ -889,6 +903,9 @@ static void cfq_group_served(struct cfq_data cfqd, struct cfq_group cfqg,
		cfqg->saved_serving_prio = cfqd->serving_prio;
		} else
		cfqg->saved_workload_slice = 0;

		cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime,
		st->min_vdisktime);
		}

		#ifdef CONFIG_CFQ_GROUP_IOSCHED
		@@ -3102,7 +3119,7 @@ static void cfq_completed_request(struct request_queue q, struct request rq)
		unsigned long now;

		now = jiffies;
		cfq_log_cfqq(cfqd, cfqq, "complete");
		cfq_log_cfqq(cfqd, cfqq, "complete rqnoidle %d", !!rq_noidle(rq));

		cfq_update_hw_tag(cfqd);

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