It helps understand how various throttle bandwidths are updated. Signed-off-by: Wu Fengguang --- include/trace/events/writeback.h | 46 +++++++++++++++++++++++++++++ mm/page-writeback.c | 3 + 2 files changed, 49 insertions(+) --- linux-next.orig/mm/page-writeback.c 2011-08-29 19:51:30.000000000 +0800 +++ linux-next/mm/page-writeback.c 2011-08-29 19:52:11.000000000 +0800 @@ -864,6 +864,9 @@ static void bdi_update_dirty_ratelimit(s dirty_ratelimit -= step; bdi->dirty_ratelimit = max(dirty_ratelimit, 1UL); + + trace_dirty_ratelimit(bdi, dirty_rate, task_ratelimit, + balanced_dirty_ratelimit); } void __bdi_update_bandwidth(struct backing_dev_info *bdi, --- linux-next.orig/include/trace/events/writeback.h 2011-08-29 19:51:30.000000000 +0800 +++ linux-next/include/trace/events/writeback.h 2011-08-29 19:52:11.000000000 +0800 @@ -226,6 +226,52 @@ TRACE_EVENT(global_dirty_state, ) ); +#define KBps(x) ((x) << (PAGE_SHIFT - 10)) + +TRACE_EVENT(dirty_ratelimit, + + TP_PROTO(struct backing_dev_info *bdi, + unsigned long dirty_rate, + unsigned long task_ratelimit, + unsigned long balanced_dirty_ratelimit), + + TP_ARGS(bdi, dirty_rate, task_ratelimit, balanced_dirty_ratelimit), + + TP_STRUCT__entry( + __array(char, bdi, 32) + __field(unsigned long, write_bw) + __field(unsigned long, avg_write_bw) + __field(unsigned long, dirty_rate) + __field(unsigned long, dirty_ratelimit) + __field(unsigned long, task_ratelimit) + __field(unsigned long, balanced_dirty_ratelimit) + ), + + TP_fast_assign( + strlcpy(__entry->bdi, dev_name(bdi->dev), 32); + __entry->write_bw = KBps(bdi->write_bandwidth); + __entry->avg_write_bw = KBps(bdi->avg_write_bandwidth); + __entry->dirty_rate = KBps(dirty_rate); + __entry->dirty_ratelimit = KBps(bdi->dirty_ratelimit); + __entry->task_ratelimit = KBps(task_ratelimit); + __entry->balanced_dirty_ratelimit = + KBps(balanced_dirty_ratelimit); + ), + + TP_printk("bdi %s: " + "write_bw=%lu awrite_bw=%lu dirty_rate=%lu " + "dirty_ratelimit=%lu task_ratelimit=%lu " + "balanced_dirty_ratelimit=%lu", + __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 */ + ) +); + DECLARE_EVENT_CLASS(writeback_congest_waited_template, TP_PROTO(unsigned int usec_timeout, unsigned int usec_delayed), -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/