Commit 6198221f authored by Keith Busch's avatar Keith Busch Committed by Matthew Wilcox
Browse files

NVMe: Disk IO statistics 



Add io stats accounting for bio requests so nvme block devices show
useful disk stats.

Signed-off-by: default avatarKeith Busch <keith.busch@intel.com>
Signed-off-by: default avatarMatthew Wilcox <matthew.r.wilcox@intel.com>
parent 063a8096

drivers/block/nvme-core.c

+28 −0
Original line number Diff line number Diff line
@@ -285,6 +285,7 @@ nvme_alloc_iod(unsigned nseg, unsigned nbytes, gfp_t gfp) 
		iod->npages = -1;

		iod->length = nbytes;

		iod->nents = 0;

		iod->start_time = jiffies;

	}



	return iod;
@@ -308,6 +309,30 @@ void nvme_free_iod(struct nvme_dev *dev, struct nvme_iod *iod) 
	kfree(iod);

}



static void nvme_start_io_acct(struct bio *bio)

{

	struct gendisk *disk = bio->bi_bdev->bd_disk;

	const int rw = bio_data_dir(bio);

	int cpu = part_stat_lock();

	part_round_stats(cpu, &disk->part0);

	part_stat_inc(cpu, &disk->part0, ios[rw]);

	part_stat_add(cpu, &disk->part0, sectors[rw], bio_sectors(bio));

	part_inc_in_flight(&disk->part0, rw);

	part_stat_unlock();

}



static void nvme_end_io_acct(struct bio *bio, unsigned long start_time)

{

	struct gendisk *disk = bio->bi_bdev->bd_disk;

	const int rw = bio_data_dir(bio);

	unsigned long duration = jiffies - start_time;

	int cpu = part_stat_lock();

	part_stat_add(cpu, &disk->part0, ticks[rw], duration);

	part_round_stats(cpu, &disk->part0);

	part_dec_in_flight(&disk->part0, rw);

	part_stat_unlock();

}



static void bio_completion(struct nvme_dev *dev, void *ctx,

						struct nvme_completion *cqe)

{
@@ -318,6 +343,8 @@ static void bio_completion(struct nvme_dev *dev, void *ctx, 
	if (iod->nents)

		dma_unmap_sg(&dev->pci_dev->dev, iod->sg, iod->nents,

			bio_data_dir(bio) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);



	nvme_end_io_acct(bio, iod->start_time);

	nvme_free_iod(dev, iod);

	if (status)

		bio_endio(bio, -EIO);
@@ -695,6 +722,7 @@ static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns, 
	cmnd->rw.control = cpu_to_le16(control);

	cmnd->rw.dsmgmt = cpu_to_le32(dsmgmt);



	nvme_start_io_acct(bio);

	if (++nvmeq->sq_tail == nvmeq->q_depth)

		nvmeq->sq_tail = 0;

	writel(nvmeq->sq_tail, nvmeq->q_db);

include/linux/nvme.h

+1 −0
Original line number Diff line number Diff line
@@ -572,6 +572,7 @@ struct nvme_iod { 
	int offset;		/* Of PRP list */

	int nents;		/* Used in scatterlist */

	int length;		/* Of data, in bytes */

	unsigned long start_time;

	dma_addr_t first_dma;

	struct scatterlist sg[0];

};