on throtl_pending_timer_fn(), the number of queued rw bios of sq and dispatched bios are logged, but the numbers are meaningless, because the dispatched bios are NOT queued on sq->queued[] instead theses bios are queued on the sq of tg queued on sq->pending_tree, so move these two throtl_log() to throtl_select_dispatch.
before patch: 1. throttle on / throtl / [R] bio. bdisp=18432 sz=262144 bps=512000 ... queued=1/0 throtl dispatch nr_queued=0 read=0 write=0 ...... throtl bios disp=1 2. throttle on / and /1 throtl /1 [R] bio. bdisp=40960 sz=262144 bps=1024000 ... queued=1/0 throtl dispatch nr_queued=0 read=0 write=0 ...... throtl bios disp=1 after patch: 1. throttle on / throtl / [R] bio. bdisp=26624 sz=262144 bps=512000 ... queued=1/0 throtl / dispatch queued=2/0 ...... throtl / dispatch disp=1 2. throttle on / and /1 throtl /1 [R] bio. bdisp=81920 sz=262144 bps=1024000 ... queued=1/0 throtl /1 dispatch queued=2/0 ...... throtl /1 dispatch disp=1 Signed-off-by: Hou Tao <[email protected]> --- block/blk-throttle.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 47a3e54..c724c97 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -974,11 +974,12 @@ static int throtl_dispatch_tg(struct throtl_grp *tg) static int throtl_select_dispatch(struct throtl_service_queue *parent_sq) { - unsigned int nr_disp = 0; + unsigned int sum_disp = 0; while (1) { struct throtl_grp *tg = throtl_rb_first(parent_sq); struct throtl_service_queue *sq = &tg->service_queue; + unsigned int nr_disp; if (!tg) break; @@ -988,16 +989,23 @@ static int throtl_select_dispatch(struct throtl_service_queue *parent_sq) throtl_dequeue_tg(tg); - nr_disp += throtl_dispatch_tg(tg); + throtl_log(sq, "dispatch queued=%u/%u", + sq->nr_queued[READ], sq->nr_queued[WRITE]); + + nr_disp = throtl_dispatch_tg(tg); + + throtl_log(sq, "dispatch disp=%u", nr_disp); + + sum_disp += nr_disp; if (sq->nr_queued[0] || sq->nr_queued[1]) tg_update_disptime(tg); - if (nr_disp >= throtl_quantum) + if (sum_disp >= throtl_quantum) break; } - return nr_disp; + return sum_disp; } /** @@ -1031,13 +1039,8 @@ again: dispatched = false; while (true) { - throtl_log(sq, "dispatch nr_queued=%u read=%u write=%u", - sq->nr_queued[READ] + sq->nr_queued[WRITE], - sq->nr_queued[READ], sq->nr_queued[WRITE]); - ret = throtl_select_dispatch(sq); if (ret) { - throtl_log(sq, "bios disp=%u", ret); dispatched = true; } -- 2.5.5
