[PATCH v2 11/17] libnvdimm: enable iostat

From: Dan Williams
Date: Thu Jun 25 2015 - 05:45:45 EST


This is disabled by default as the overhead is prohibitive, but if the
user takes the action to turn it on we'll oblige.

Reviewed-by: Vishal Verma <vishal.l.verma@xxxxxxxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/nvdimm/blk.c | 7 ++++++-
drivers/nvdimm/btt.c | 7 ++++++-
drivers/nvdimm/core.c | 29 +++++++++++++++++++++++++++++
drivers/nvdimm/nd.h | 13 +++++++++++++
drivers/nvdimm/pmem.c | 5 +++++
5 files changed, 59 insertions(+), 2 deletions(-)

diff --git a/drivers/nvdimm/blk.c b/drivers/nvdimm/blk.c
index 5c44e067652f..96ef38ceeceb 100644
--- a/drivers/nvdimm/blk.c
+++ b/drivers/nvdimm/blk.c
@@ -168,8 +168,10 @@ static void nd_blk_make_request(struct request_queue *q, struct bio *bio)
struct bio_integrity_payload *bip;
struct nd_blk_device *blk_dev;
struct bvec_iter iter;
+ unsigned long start;
struct bio_vec bvec;
int err = 0, rw;
+ bool do_acct;

/*
* bio_integrity_enabled also checks if the bio already has an
@@ -185,6 +187,7 @@ static void nd_blk_make_request(struct request_queue *q, struct bio *bio)
bip = bio_integrity(bio);
blk_dev = disk->private_data;
rw = bio_data_dir(bio);
+ do_acct = nd_iostat_start(bio, &start);
bio_for_each_segment(bvec, bio, iter) {
unsigned int len = bvec.bv_len;

@@ -196,9 +199,11 @@ static void nd_blk_make_request(struct request_queue *q, struct bio *bio)
"io error in %s sector %lld, len %d,\n",
(rw == READ) ? "READ" : "WRITE",
(unsigned long long) iter.bi_sector, len);
- goto out;
+ break;
}
}
+ if (do_acct)
+ nd_iostat_end(bio, start);

out:
bio_endio(bio, err);
diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c
index 18a2463c2300..c02065aed03d 100644
--- a/drivers/nvdimm/btt.c
+++ b/drivers/nvdimm/btt.c
@@ -1177,8 +1177,10 @@ static void btt_make_request(struct request_queue *q, struct bio *bio)
struct bio_integrity_payload *bip = bio_integrity(bio);
struct btt *btt = q->queuedata;
struct bvec_iter iter;
+ unsigned long start;
struct bio_vec bvec;
int err = 0, rw;
+ bool do_acct;

/*
* bio_integrity_enabled also checks if the bio already has an
@@ -1191,6 +1193,7 @@ static void btt_make_request(struct request_queue *q, struct bio *bio)
goto out;
}

+ do_acct = nd_iostat_start(bio, &start);
rw = bio_data_dir(bio);
bio_for_each_segment(bvec, bio, iter) {
unsigned int len = bvec.bv_len;
@@ -1208,9 +1211,11 @@ static void btt_make_request(struct request_queue *q, struct bio *bio)
"io error in %s sector %lld, len %d,\n",
(rw == READ) ? "READ" : "WRITE",
(unsigned long long) iter.bi_sector, len);
- goto out;
+ break;
}
}
+ if (do_acct)
+ nd_iostat_end(bio, start);

out:
bio_endio(bio, err);
diff --git a/drivers/nvdimm/core.c b/drivers/nvdimm/core.c
index 4288169432de..cb62ec6a12d0 100644
--- a/drivers/nvdimm/core.c
+++ b/drivers/nvdimm/core.c
@@ -214,6 +214,35 @@ ssize_t nd_sector_size_store(struct device *dev, const char *buf,
}
}

+void __nd_iostat_start(struct bio *bio, unsigned long *start)
+{
+ struct gendisk *disk = bio->bi_bdev->bd_disk;
+ const int rw = bio_data_dir(bio);
+ int cpu = part_stat_lock();
+
+ *start = jiffies;
+ 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();
+}
+EXPORT_SYMBOL(__nd_iostat_start);
+
+void nd_iostat_end(struct bio *bio, unsigned long start)
+{
+ struct gendisk *disk = bio->bi_bdev->bd_disk;
+ unsigned long duration = jiffies - start;
+ const int rw = bio_data_dir(bio);
+ 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();
+}
+EXPORT_SYMBOL(nd_iostat_end);
+
static ssize_t commands_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index e73c34dcd935..cf6849b72c4f 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -13,6 +13,7 @@
#ifndef __ND_H__
#define __ND_H__
#include <linux/libnvdimm.h>
+#include <linux/blkdev.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/ndctl.h>
@@ -201,5 +202,17 @@ int nvdimm_namespace_detach_btt(struct nd_namespace_common *ndns);
const char *nvdimm_namespace_disk_name(struct nd_namespace_common *ndns,
char *name);
int nd_blk_region_init(struct nd_region *nd_region);
+void __nd_iostat_start(struct bio *bio, unsigned long *start);
+static inline bool nd_iostat_start(struct bio *bio, unsigned long *start)
+{
+ struct gendisk *disk = bio->bi_bdev->bd_disk;
+
+ if (!blk_queue_io_stat(disk->queue))
+ return false;
+
+ __nd_iostat_start(bio, start);
+ return true;
+}
+void nd_iostat_end(struct bio *bio, unsigned long start);
resource_size_t nd_namespace_blk_validate(struct nd_namespace_blk *nsblk);
#endif /* __ND_H__ */
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index e846a627ebdf..09195e3b7453 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -58,14 +58,19 @@ static void pmem_do_bvec(struct pmem_device *pmem, struct page *page,

static void pmem_make_request(struct request_queue *q, struct bio *bio)
{
+ bool do_acct;
+ unsigned long start;
struct bio_vec bvec;
struct bvec_iter iter;
struct block_device *bdev = bio->bi_bdev;
struct pmem_device *pmem = bdev->bd_disk->private_data;

+ do_acct = nd_iostat_start(bio, &start);
bio_for_each_segment(bvec, bio, iter)
pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len, bvec.bv_offset,
bio_data_dir(bio), iter.bi_sector);
+ if (do_acct)
+ nd_iostat_end(bio, start);
bio_endio(bio, 0);
}


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