From 2868ef7b39490e6b41c2c61cd9a5cd891e778b54 Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Thu, 3 Dec 2009 12:59:48 -0500 Subject: [PATCH] blkio: Some debugging aids for CFQ o Some debugging aids for CFQ. Signed-off-by: Vivek Goyal Signed-off-by: Jens Axboe --- block/Kconfig | 9 +++++++++ block/Kconfig.iosched | 9 +++++++++ block/blk-cgroup.c | 4 ++++ block/blk-cgroup.h | 13 +++++++++++++ block/cfq-iosched.c | 19 ++++++++++++++++++- 5 files changed, 53 insertions(+), 1 deletion(-) diff --git a/block/Kconfig b/block/Kconfig index 6ba1a8e3388..e20fbde0875 100644 --- a/block/Kconfig +++ b/block/Kconfig @@ -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 diff --git a/block/Kconfig.iosched b/block/Kconfig.iosched index fa95fa77057..b71abfb0d72 100644 --- a/block/Kconfig.iosched +++ b/block/Kconfig.iosched @@ -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 diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 0426ab692fd..6bc99a3865b 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -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) diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index cd50a2f8733..3573199b298 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -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); diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 8bc31a50a57..662d4e55b3c 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -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);