Commit 7cd54aa8 authored by Jens Axboe's avatar Jens Axboe
Browse files

blk-stat: fix a few cases of missing batch flushing 



Everytime we need to read ->nr_samples, we should have flushed
the batch first. The non-mq read path also needs to flush the
batch.

Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent c8e52ba5

block/blk-stat.c

+8 −0
Original line number Diff line number Diff line
@@ -64,6 +64,9 @@ static void blk_mq_stat_get(struct request_queue *q, struct blk_rq_stat *dst) 


		queue_for_each_hw_ctx(q, hctx, i) {

			hctx_for_each_ctx(hctx, ctx, j) {

				blk_stat_flush_batch(&ctx->stat[BLK_STAT_READ]);

				blk_stat_flush_batch(&ctx->stat[BLK_STAT_WRITE]);



				if (!ctx->stat[BLK_STAT_READ].nr_samples &&

				    !ctx->stat[BLK_STAT_WRITE].nr_samples)

					continue;
@@ -111,6 +114,8 @@ void blk_queue_stat_get(struct request_queue *q, struct blk_rq_stat *dst) 
	if (q->mq_ops)

		blk_mq_stat_get(q, dst);

	else {

		blk_stat_flush_batch(&q->rq_stats[BLK_STAT_READ]);

		blk_stat_flush_batch(&q->rq_stats[BLK_STAT_WRITE]);

		memcpy(&dst[BLK_STAT_READ], &q->rq_stats[BLK_STAT_READ],

				sizeof(struct blk_rq_stat));

		memcpy(&dst[BLK_STAT_WRITE], &q->rq_stats[BLK_STAT_WRITE],
@@ -128,6 +133,9 @@ void blk_hctx_stat_get(struct blk_mq_hw_ctx *hctx, struct blk_rq_stat *dst) 
		uint64_t newest = 0;



		hctx_for_each_ctx(hctx, ctx, i) {

			blk_stat_flush_batch(&ctx->stat[BLK_STAT_READ]);

			blk_stat_flush_batch(&ctx->stat[BLK_STAT_WRITE]);



			if (!ctx->stat[BLK_STAT_READ].nr_samples &&

			    !ctx->stat[BLK_STAT_WRITE].nr_samples)

				continue;

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