From 5634cc2aa9aebc77bc862992e7805469dcf83dac Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 18 Aug 2015 14:54:56 -0700 Subject: [PATCH] writeback: update writeback tracepoints to report cgroup The following tracepoints are updated to report the cgroup used during cgroup writeback. * writeback_write_inode[_start] * writeback_queue * writeback_exec * writeback_start * writeback_written * writeback_wait * writeback_nowork * writeback_wake_background * wbc_writepage * writeback_queue_io * bdi_dirty_ratelimit * balance_dirty_pages * writeback_sb_inodes_requeue * writeback_single_inode[_start] Note that writeback_bdi_register is separated out from writeback_class as reporting cgroup doesn't make sense to it. Tracepoints which take bdi are updated to take bdi_writeback instead. Signed-off-by: Tejun Heo Suggested-by: Jan Kara Reviewed-by: Jan Kara Signed-off-by: Jens Axboe --- fs/fs-writeback.c | 14 +-- include/trace/events/writeback.h | 182 ++++++++++++++++++++++++------- mm/page-writeback.c | 6 +- 3 files changed, 152 insertions(+), 50 deletions(-) diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 128404310fc0..f4f0f228a530 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -176,7 +176,7 @@ static void wb_wakeup(struct bdi_writeback *wb) static void wb_queue_work(struct bdi_writeback *wb, struct wb_writeback_work *work) { - trace_writeback_queue(wb->bdi, work); + trace_writeback_queue(wb, work); spin_lock_bh(&wb->work_lock); if (!test_bit(WB_registered, &wb->state)) @@ -883,7 +883,7 @@ void wb_start_writeback(struct bdi_writeback *wb, long nr_pages, */ work = kzalloc(sizeof(*work), GFP_ATOMIC); if (!work) { - trace_writeback_nowork(wb->bdi); + trace_writeback_nowork(wb); wb_wakeup(wb); return; } @@ -913,7 +913,7 @@ void wb_start_background_writeback(struct bdi_writeback *wb) * We just wake up the flusher thread. It will perform background * writeback as soon as there is no other work to do. */ - trace_writeback_wake_background(wb->bdi); + trace_writeback_wake_background(wb); wb_wakeup(wb); } @@ -1616,14 +1616,14 @@ static long wb_writeback(struct bdi_writeback *wb, } else if (work->for_background) oldest_jif = jiffies; - trace_writeback_start(wb->bdi, work); + trace_writeback_start(wb, work); if (list_empty(&wb->b_io)) queue_io(wb, work); if (work->sb) progress = writeback_sb_inodes(work->sb, wb, work); else progress = __writeback_inodes_wb(wb, work); - trace_writeback_written(wb->bdi, work); + trace_writeback_written(wb, work); wb_update_bandwidth(wb, wb_start); @@ -1648,7 +1648,7 @@ static long wb_writeback(struct bdi_writeback *wb, * we'll just busyloop. */ if (!list_empty(&wb->b_more_io)) { - trace_writeback_wait(wb->bdi, work); + trace_writeback_wait(wb, work); inode = wb_inode(wb->b_more_io.prev); spin_lock(&inode->i_lock); spin_unlock(&wb->list_lock); @@ -1754,7 +1754,7 @@ static long wb_do_writeback(struct bdi_writeback *wb) while ((work = get_next_work_item(wb)) != NULL) { struct wb_completion *done = work->done; - trace_writeback_exec(wb->bdi, work); + trace_writeback_exec(wb, work); wrote += wb_writeback(wb, work); diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h index a7aa607a4c55..fff846b512e6 100644 --- a/include/trace/events/writeback.h +++ b/include/trace/events/writeback.h @@ -131,6 +131,66 @@ DEFINE_EVENT(writeback_dirty_inode_template, writeback_dirty_inode, TP_ARGS(inode, flags) ); +#ifdef CREATE_TRACE_POINTS +#ifdef CONFIG_CGROUP_WRITEBACK + +static inline size_t __trace_wb_cgroup_size(struct bdi_writeback *wb) +{ + return kernfs_path_len(wb->memcg_css->cgroup->kn) + 1; +} + +static inline void __trace_wb_assign_cgroup(char *buf, struct bdi_writeback *wb) +{ + struct cgroup *cgrp = wb->memcg_css->cgroup; + char *path; + + path = cgroup_path(cgrp, buf, kernfs_path_len(cgrp->kn) + 1); + WARN_ON_ONCE(path != buf); +} + +static inline size_t __trace_wbc_cgroup_size(struct writeback_control *wbc) +{ + if (wbc->wb) + return __trace_wb_cgroup_size(wbc->wb); + else + return 2; +} + +static inline void __trace_wbc_assign_cgroup(char *buf, + struct writeback_control *wbc) +{ + if (wbc->wb) + __trace_wb_assign_cgroup(buf, wbc->wb); + else + strcpy(buf, "/"); +} + +#else /* CONFIG_CGROUP_WRITEBACK */ + +static inline size_t __trace_wb_cgroup_size(struct bdi_writeback *wb) +{ + return 2; +} + +static inline void __trace_wb_assign_cgroup(char *buf, struct bdi_writeback *wb) +{ + strcpy(buf, "/"); +} + +static inline size_t __trace_wbc_cgroup_size(struct writeback_control *wbc) +{ + return 2; +} + +static inline void __trace_wbc_assign_cgroup(char *buf, + struct writeback_control *wbc) +{ + strcpy(buf, "/"); +} + +#endif /* CONFIG_CGROUP_WRITEBACK */ +#endif /* CREATE_TRACE_POINTS */ + DECLARE_EVENT_CLASS(writeback_write_inode_template, TP_PROTO(struct inode *inode, struct writeback_control *wbc), @@ -141,6 +201,7 @@ DECLARE_EVENT_CLASS(writeback_write_inode_template, __array(char, name, 32) __field(unsigned long, ino) __field(int, sync_mode) + __dynamic_array(char, cgroup, __trace_wbc_cgroup_size(wbc)) ), TP_fast_assign( @@ -148,12 +209,14 @@ DECLARE_EVENT_CLASS(writeback_write_inode_template, dev_name(inode_to_bdi(inode)->dev), 32); __entry->ino = inode->i_ino; __entry->sync_mode = wbc->sync_mode; + __trace_wbc_assign_cgroup(__get_str(cgroup), wbc); ), - TP_printk("bdi %s: ino=%lu sync_mode=%d", + TP_printk("bdi %s: ino=%lu sync_mode=%d cgroup=%s", __entry->name, __entry->ino, - __entry->sync_mode + __entry->sync_mode, + __get_str(cgroup) ) ); @@ -172,8 +235,8 @@ DEFINE_EVENT(writeback_write_inode_template, writeback_write_inode, ); DECLARE_EVENT_CLASS(writeback_work_class, - TP_PROTO(struct backing_dev_info *bdi, struct wb_writeback_work *work), - TP_ARGS(bdi, work), + TP_PROTO(struct bdi_writeback *wb, struct wb_writeback_work *work), + TP_ARGS(wb, work), TP_STRUCT__entry( __array(char, name, 32) __field(long, nr_pages) @@ -183,10 +246,11 @@ DECLARE_EVENT_CLASS(writeback_work_class, __field(int, range_cyclic) __field(int, for_background) __field(int, reason) + __dynamic_array(char, cgroup, __trace_wb_cgroup_size(wb)) ), TP_fast_assign( strncpy(__entry->name, - bdi->dev ? dev_name(bdi->dev) : "(unknown)", 32); + wb->bdi->dev ? dev_name(wb->bdi->dev) : "(unknown)", 32); __entry->nr_pages = work->nr_pages; __entry->sb_dev = work->sb ? work->sb->s_dev : 0; __entry->sync_mode = work->sync_mode; @@ -194,9 +258,10 @@ DECLARE_EVENT_CLASS(writeback_work_class, __entry->range_cyclic = work->range_cyclic; __entry->for_background = work->for_background; __entry->reason = work->reason; + __trace_wb_assign_cgroup(__get_str(cgroup), wb); ), TP_printk("bdi %s: sb_dev %d:%d nr_pages=%ld sync_mode=%d " - "kupdate=%d range_cyclic=%d background=%d reason=%s", + "kupdate=%d range_cyclic=%d background=%d reason=%s cgroup=%s", __entry->name, MAJOR(__entry->sb_dev), MINOR(__entry->sb_dev), __entry->nr_pages, @@ -204,13 +269,14 @@ DECLARE_EVENT_CLASS(writeback_work_class, __entry->for_kupdate, __entry->range_cyclic, __entry->for_background, - __print_symbolic(__entry->reason, WB_WORK_REASON) + __print_symbolic(__entry->reason, WB_WORK_REASON), + __get_str(cgroup) ) ); #define DEFINE_WRITEBACK_WORK_EVENT(name) \ DEFINE_EVENT(writeback_work_class, name, \ - TP_PROTO(struct backing_dev_info *bdi, struct wb_writeback_work *work), \ - TP_ARGS(bdi, work)) + TP_PROTO(struct bdi_writeback *wb, struct wb_writeback_work *work), \ + TP_ARGS(wb, work)) DEFINE_WRITEBACK_WORK_EVENT(writeback_queue); DEFINE_WRITEBACK_WORK_EVENT(writeback_exec); DEFINE_WRITEBACK_WORK_EVENT(writeback_start); @@ -230,6 +296,30 @@ TRACE_EVENT(writeback_pages_written, ); DECLARE_EVENT_CLASS(writeback_class, + TP_PROTO(struct bdi_writeback *wb), + TP_ARGS(wb), + TP_STRUCT__entry( + __array(char, name, 32) + __dynamic_array(char, cgroup, __trace_wb_cgroup_size(wb)) + ), + TP_fast_assign( + strncpy(__entry->name, dev_name(wb->bdi->dev), 32); + __trace_wb_assign_cgroup(__get_str(cgroup), wb); + ), + TP_printk("bdi %s: cgroup=%s", + __entry->name, + __get_str(cgroup) + ) +); +#define DEFINE_WRITEBACK_EVENT(name) \ +DEFINE_EVENT(writeback_class, name, \ + TP_PROTO(struct bdi_writeback *wb), \ + TP_ARGS(wb)) + +DEFINE_WRITEBACK_EVENT(writeback_nowork); +DEFINE_WRITEBACK_EVENT(writeback_wake_background); + +TRACE_EVENT(writeback_bdi_register, TP_PROTO(struct backing_dev_info *bdi), TP_ARGS(bdi), TP_STRUCT__entry( @@ -239,17 +329,9 @@ DECLARE_EVENT_CLASS(writeback_class, strncpy(__entry->name, dev_name(bdi->dev), 32); ), TP_printk("bdi %s", - __entry->name + __entry->name ) ); -#define DEFINE_WRITEBACK_EVENT(name) \ -DEFINE_EVENT(writeback_class, name, \ - TP_PROTO(struct backing_dev_info *bdi), \ - TP_ARGS(bdi)) - -DEFINE_WRITEBACK_EVENT(writeback_nowork); -DEFINE_WRITEBACK_EVENT(writeback_wake_background); -DEFINE_WRITEBACK_EVENT(writeback_bdi_register); DECLARE_EVENT_CLASS(wbc_class, TP_PROTO(struct writeback_control *wbc, struct backing_dev_info *bdi), @@ -265,6 +347,7 @@ DECLARE_EVENT_CLASS(wbc_class, __field(int, range_cyclic) __field(long, range_start) __field(long, range_end) + __dynamic_array(char, cgroup, __trace_wbc_cgroup_size(wbc)) ), TP_fast_assign( @@ -278,11 +361,12 @@ DECLARE_EVENT_CLASS(wbc_class, __entry->range_cyclic = wbc->range_cyclic; __entry->range_start = (long)wbc->range_start; __entry->range_end = (long)wbc->range_end; + __trace_wbc_assign_cgroup(__get_str(cgroup), wbc); ), TP_printk("bdi %s: towrt=%ld skip=%ld mode=%d kupd=%d " "bgrd=%d reclm=%d cyclic=%d " - "start=0x%lx end=0x%lx", + "start=0x%lx end=0x%lx cgroup=%s", __entry->name, __entry->nr_to_write, __entry->pages_skipped, @@ -292,7 +376,9 @@ DECLARE_EVENT_CLASS(wbc_class, __entry->for_reclaim, __entry->range_cyclic, __entry->range_start, - __entry->range_end) + __entry->range_end, + __get_str(cgroup) + ) ) #define DEFINE_WBC_EVENT(name) \ @@ -312,6 +398,7 @@ TRACE_EVENT(writeback_queue_io, __field(long, age) __field(int, moved) __field(int, reason) + __dynamic_array(char, cgroup, __trace_wb_cgroup_size(wb)) ), TP_fast_assign( unsigned long *older_than_this = work->older_than_this; @@ -321,13 +408,15 @@ TRACE_EVENT(writeback_queue_io, (jiffies - *older_than_this) * 1000 / HZ : -1; __entry->moved = moved; __entry->reason = work->reason; + __trace_wb_assign_cgroup(__get_str(cgroup), wb); ), - TP_printk("bdi %s: older=%lu age=%ld enqueue=%d reason=%s", + TP_printk("bdi %s: older=%lu age=%ld enqueue=%d reason=%s cgroup=%s", __entry->name, __entry->older, /* older_than_this in jiffies */ __entry->age, /* older_than_this in relative milliseconds */ __entry->moved, - __print_symbolic(__entry->reason, WB_WORK_REASON) + __print_symbolic(__entry->reason, WB_WORK_REASON), + __get_str(cgroup) ) ); @@ -381,11 +470,11 @@ TRACE_EVENT(global_dirty_state, TRACE_EVENT(bdi_dirty_ratelimit, - TP_PROTO(struct backing_dev_info *bdi, + TP_PROTO(struct bdi_writeback *wb, unsigned long dirty_rate, unsigned long task_ratelimit), - TP_ARGS(bdi, dirty_rate, task_ratelimit), + TP_ARGS(wb, dirty_rate, task_ratelimit), TP_STRUCT__entry( __array(char, bdi, 32) @@ -395,36 +484,39 @@ TRACE_EVENT(bdi_dirty_ratelimit, __field(unsigned long, dirty_ratelimit) __field(unsigned long, task_ratelimit) __field(unsigned long, balanced_dirty_ratelimit) + __dynamic_array(char, cgroup, __trace_wb_cgroup_size(wb)) ), TP_fast_assign( - strlcpy(__entry->bdi, dev_name(bdi->dev), 32); - __entry->write_bw = KBps(bdi->wb.write_bandwidth); - __entry->avg_write_bw = KBps(bdi->wb.avg_write_bandwidth); + strlcpy(__entry->bdi, dev_name(wb->bdi->dev), 32); + __entry->write_bw = KBps(wb->write_bandwidth); + __entry->avg_write_bw = KBps(wb->avg_write_bandwidth); __entry->dirty_rate = KBps(dirty_rate); - __entry->dirty_ratelimit = KBps(bdi->wb.dirty_ratelimit); + __entry->dirty_ratelimit = KBps(wb->dirty_ratelimit); __entry->task_ratelimit = KBps(task_ratelimit); __entry->balanced_dirty_ratelimit = - KBps(bdi->wb.balanced_dirty_ratelimit); + KBps(wb->balanced_dirty_ratelimit); + __trace_wb_assign_cgroup(__get_str(cgroup), wb); ), TP_printk("bdi %s: " "write_bw=%lu awrite_bw=%lu dirty_rate=%lu " "dirty_ratelimit=%lu task_ratelimit=%lu " - "balanced_dirty_ratelimit=%lu", + "balanced_dirty_ratelimit=%lu cgroup=%s", __entry->bdi, __entry->write_bw, /* write bandwidth */ __entry->avg_write_bw, /* avg write bandwidth */ __entry->dirty_rate, /* bdi dirty rate */ __entry->dirty_ratelimit, /* base ratelimit */ __entry->task_ratelimit, /* ratelimit with position control */ - __entry->balanced_dirty_ratelimit /* the balanced ratelimit */ + __entry->balanced_dirty_ratelimit, /* the balanced ratelimit */ + __get_str(cgroup) ) ); TRACE_EVENT(balance_dirty_pages, - TP_PROTO(struct backing_dev_info *bdi, + TP_PROTO(struct bdi_writeback *wb, unsigned long thresh, unsigned long bg_thresh, unsigned long dirty, @@ -437,7 +529,7 @@ TRACE_EVENT(balance_dirty_pages, long pause, unsigned long start_time), - TP_ARGS(bdi, thresh, bg_thresh, dirty, bdi_thresh, bdi_dirty, + TP_ARGS(wb, thresh, bg_thresh, dirty, bdi_thresh, bdi_dirty, dirty_ratelimit, task_ratelimit, dirtied, period, pause, start_time), @@ -456,11 +548,12 @@ TRACE_EVENT(balance_dirty_pages, __field( long, pause) __field(unsigned long, period) __field( long, think) + __dynamic_array(char, cgroup, __trace_wb_cgroup_size(wb)) ), TP_fast_assign( unsigned long freerun = (thresh + bg_thresh) / 2; - strlcpy(__entry->bdi, dev_name(bdi->dev), 32); + strlcpy(__entry->bdi, dev_name(wb->bdi->dev), 32); __entry->limit = global_wb_domain.dirty_limit; __entry->setpoint = (global_wb_domain.dirty_limit + @@ -478,6 +571,7 @@ TRACE_EVENT(balance_dirty_pages, __entry->period = period * 1000 / HZ; __entry->pause = pause * 1000 / HZ; __entry->paused = (jiffies - start_time) * 1000 / HZ; + __trace_wb_assign_cgroup(__get_str(cgroup), wb); ), @@ -486,7 +580,7 @@ TRACE_EVENT(balance_dirty_pages, "bdi_setpoint=%lu bdi_dirty=%lu " "dirty_ratelimit=%lu task_ratelimit=%lu " "dirtied=%u dirtied_pause=%u " - "paused=%lu pause=%ld period=%lu think=%ld", + "paused=%lu pause=%ld period=%lu think=%ld cgroup=%s", __entry->bdi, __entry->limit, __entry->setpoint, @@ -500,7 +594,8 @@ TRACE_EVENT(balance_dirty_pages, __entry->paused, /* ms */ __entry->pause, /* ms */ __entry->period, /* ms */ - __entry->think /* ms */ + __entry->think, /* ms */ + __get_str(cgroup) ) ); @@ -514,6 +609,8 @@ TRACE_EVENT(writeback_sb_inodes_requeue, __field(unsigned long, ino) __field(unsigned long, state) __field(unsigned long, dirtied_when) + __dynamic_array(char, cgroup, + __trace_wb_cgroup_size(inode_to_wb(inode))) ), TP_fast_assign( @@ -522,14 +619,16 @@ TRACE_EVENT(writeback_sb_inodes_requeue, __entry->ino = inode->i_ino; __entry->state = inode->i_state; __entry->dirtied_when = inode->dirtied_when; + __trace_wb_assign_cgroup(__get_str(cgroup), inode_to_wb(inode)); ), - TP_printk("bdi %s: ino=%lu state=%s dirtied_when=%lu age=%lu", + TP_printk("bdi %s: ino=%lu state=%s dirtied_when=%lu age=%lu cgroup=%s", __entry->name, __entry->ino, show_inode_state(__entry->state), __entry->dirtied_when, - (jiffies - __entry->dirtied_when) / HZ + (jiffies - __entry->dirtied_when) / HZ, + __get_str(cgroup) ) ); @@ -585,6 +684,7 @@ DECLARE_EVENT_CLASS(writeback_single_inode_template, __field(unsigned long, writeback_index) __field(long, nr_to_write) __field(unsigned long, wrote) + __dynamic_array(char, cgroup, __trace_wbc_cgroup_size(wbc)) ), TP_fast_assign( @@ -596,10 +696,11 @@ DECLARE_EVENT_CLASS(writeback_single_inode_template, __entry->writeback_index = inode->i_mapping->writeback_index; __entry->nr_to_write = nr_to_write; __entry->wrote = nr_to_write - wbc->nr_to_write; + __trace_wbc_assign_cgroup(__get_str(cgroup), wbc); ), TP_printk("bdi %s: ino=%lu state=%s dirtied_when=%lu age=%lu " - "index=%lu to_write=%ld wrote=%lu", + "index=%lu to_write=%ld wrote=%lu cgroup=%s", __entry->name, __entry->ino, show_inode_state(__entry->state), @@ -607,7 +708,8 @@ DECLARE_EVENT_CLASS(writeback_single_inode_template, (jiffies - __entry->dirtied_when) / HZ, __entry->writeback_index, __entry->nr_to_write, - __entry->wrote + __entry->wrote, + __get_str(cgroup) ) ); diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 22cddd3e5de8..802beeb6b86b 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1289,7 +1289,7 @@ static void wb_update_dirty_ratelimit(struct dirty_throttle_control *dtc, wb->dirty_ratelimit = max(dirty_ratelimit, 1UL); wb->balanced_dirty_ratelimit = balanced_dirty_ratelimit; - trace_bdi_dirty_ratelimit(wb->bdi, dirty_rate, task_ratelimit); + trace_bdi_dirty_ratelimit(wb, dirty_rate, task_ratelimit); } static void __wb_update_bandwidth(struct dirty_throttle_control *gdtc, @@ -1683,7 +1683,7 @@ static void balance_dirty_pages(struct address_space *mapping, * do a reset, as it may be a light dirtier. */ if (pause < min_pause) { - trace_balance_dirty_pages(bdi, + trace_balance_dirty_pages(wb, sdtc->thresh, sdtc->bg_thresh, sdtc->dirty, @@ -1712,7 +1712,7 @@ static void balance_dirty_pages(struct address_space *mapping, } pause: - trace_balance_dirty_pages(bdi, + trace_balance_dirty_pages(wb, sdtc->thresh, sdtc->bg_thresh, sdtc->dirty,