From: "Matias Bjørling" <mb@lightnvm.io>
To: axboe@fb.com
Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
keith.busch@intel.com, javier@cnexlabs.com,
"Hans Holmberg" <hans.holmberg@cnexlabs.com>,
"Matias Bjørling" <mb@lightnvm.io>
Subject: [GIT PULL 08/37] lightnvm: pblk: add padding distribution sysfs attribute
Date: Fri, 30 Mar 2018 00:04:55 +0200 [thread overview]
Message-ID: <20180329220524.30363-9-mb@lightnvm.io> (raw)
In-Reply-To: <20180329220524.30363-1-mb@lightnvm.io>
From: Hans Holmberg <hans.holmberg@cnexlabs.com>
When pblk receives a sync, all data up to that point in the write buffer
must be comitted to persistent storage, and as flash memory comes with a
minimal write size there is a significant cost involved both in terms
of time for completing the sync and in terms of write amplification
padded sectors for filling up to the minimal write size.
In order to get a better understanding of the costs involved for syncs,
Add a sysfs attribute to pblk: padded_dist, showing a normalized
distribution of sectors padded. In order to facilitate measurements of
specific workloads during the lifetime of the pblk instance, the
distribution can be reset by writing 0 to the attribute.
Do this by introducing counters for each possible padding:
{0..(minimal write size - 1)} and calculate the normalized distribution
when showing the attribute.
Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com>
Signed-off-by: Javier González <javier@cnexlabs.com>
Rearranged total_buckets statement in pblk_sysfs_get_padding_dist
Signed-off-by: Matias Bjørling <mb@lightnvm.io>
---
drivers/lightnvm/pblk-init.c | 16 +++++++-
drivers/lightnvm/pblk-rb.c | 17 +++++----
drivers/lightnvm/pblk-sysfs.c | 87 ++++++++++++++++++++++++++++++++++++++++++-
drivers/lightnvm/pblk.h | 6 ++-
4 files changed, 113 insertions(+), 13 deletions(-)
diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
index 0ffc17ccf1cc..8416910ee8bf 100644
--- a/drivers/lightnvm/pblk-init.c
+++ b/drivers/lightnvm/pblk-init.c
@@ -921,6 +921,7 @@ static void pblk_free(struct pblk *pblk)
{
pblk_luns_free(pblk);
pblk_lines_free(pblk);
+ kfree(pblk->pad_dist);
pblk_line_meta_free(pblk);
pblk_core_free(pblk);
pblk_l2p_free(pblk);
@@ -998,11 +999,13 @@ static void *pblk_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
pblk->pad_rst_wa = 0;
pblk->gc_rst_wa = 0;
+ atomic64_set(&pblk->nr_flush, 0);
+ pblk->nr_flush_rst = 0;
+
#ifdef CONFIG_NVM_DEBUG
atomic_long_set(&pblk->inflight_writes, 0);
atomic_long_set(&pblk->padded_writes, 0);
atomic_long_set(&pblk->padded_wb, 0);
- atomic_long_set(&pblk->nr_flush, 0);
atomic_long_set(&pblk->req_writes, 0);
atomic_long_set(&pblk->sub_writes, 0);
atomic_long_set(&pblk->sync_writes, 0);
@@ -1034,10 +1037,17 @@ static void *pblk_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
goto fail_free_luns;
}
+ pblk->pad_dist = kzalloc((pblk->min_write_pgs - 1) * sizeof(atomic64_t),
+ GFP_KERNEL);
+ if (!pblk->pad_dist) {
+ ret = -ENOMEM;
+ goto fail_free_line_meta;
+ }
+
ret = pblk_core_init(pblk);
if (ret) {
pr_err("pblk: could not initialize core\n");
- goto fail_free_line_meta;
+ goto fail_free_pad_dist;
}
ret = pblk_l2p_init(pblk);
@@ -1097,6 +1107,8 @@ static void *pblk_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
pblk_l2p_free(pblk);
fail_free_core:
pblk_core_free(pblk);
+fail_free_pad_dist:
+ kfree(pblk->pad_dist);
fail_free_line_meta:
pblk_line_meta_free(pblk);
fail_free_luns:
diff --git a/drivers/lightnvm/pblk-rb.c b/drivers/lightnvm/pblk-rb.c
index 7044b5599cc4..8b1434060fb3 100644
--- a/drivers/lightnvm/pblk-rb.c
+++ b/drivers/lightnvm/pblk-rb.c
@@ -437,9 +437,7 @@ static int pblk_rb_may_write_flush(struct pblk_rb *rb, unsigned int nr_entries,
if (bio->bi_opf & REQ_PREFLUSH) {
struct pblk *pblk = container_of(rb, struct pblk, rwb);
-#ifdef CONFIG_NVM_DEBUG
- atomic_long_inc(&pblk->nr_flush);
-#endif
+ atomic64_inc(&pblk->nr_flush);
if (pblk_rb_flush_point_set(&pblk->rwb, bio, mem))
*io_ret = NVM_IO_OK;
}
@@ -620,14 +618,17 @@ unsigned int pblk_rb_read_to_bio(struct pblk_rb *rb, struct nvm_rq *rqd,
pr_err("pblk: could not pad page in write bio\n");
return NVM_IO_ERR;
}
+
+ if (pad < pblk->min_write_pgs)
+ atomic64_inc(&pblk->pad_dist[pad - 1]);
+ else
+ pr_warn("pblk: padding more than min. sectors\n");
+
+ atomic64_add(pad, &pblk->pad_wa);
}
- atomic64_add(pad, &((struct pblk *)
- (container_of(rb, struct pblk, rwb)))->pad_wa);
-
#ifdef CONFIG_NVM_DEBUG
- atomic_long_add(pad, &((struct pblk *)
- (container_of(rb, struct pblk, rwb)))->padded_writes);
+ atomic_long_add(pad, &pblk->padded_writes);
#endif
return NVM_IO_OK;
diff --git a/drivers/lightnvm/pblk-sysfs.c b/drivers/lightnvm/pblk-sysfs.c
index beed99936c89..c2cf6c939752 100644
--- a/drivers/lightnvm/pblk-sysfs.c
+++ b/drivers/lightnvm/pblk-sysfs.c
@@ -340,15 +340,62 @@ static ssize_t pblk_sysfs_get_write_amp_trip(struct pblk *pblk, char *page)
atomic64_read(&pblk->pad_wa) - pblk->pad_rst_wa, page);
}
+static long long bucket_percentage(unsigned long long bucket,
+ unsigned long long total)
+{
+ int p = bucket * 100;
+
+ p = div_u64(p, total);
+
+ return p;
+}
+
+static ssize_t pblk_sysfs_get_padding_dist(struct pblk *pblk, char *page)
+{
+ int sz = 0;
+ unsigned long long total;
+ unsigned long long total_buckets = 0;
+ int buckets = pblk->min_write_pgs - 1;
+ int i;
+
+ total = atomic64_read(&pblk->nr_flush) - pblk->nr_flush_rst;
+ if (!total) {
+ for (i = 0; i < (buckets + 1); i++)
+ sz += snprintf(page + sz, PAGE_SIZE - sz,
+ "%d:0 ", i);
+ sz += snprintf(page + sz, PAGE_SIZE - sz, "\n");
+
+ return sz;
+ }
+
+ for (i = 0; i < buckets; i++)
+ total_buckets += atomic64_read(&pblk->pad_dist[i]);
+
+ sz += snprintf(page + sz, PAGE_SIZE - sz, "0:%lld%% ",
+ bucket_percentage(total - total_buckets, total));
+
+ for (i = 0; i < buckets; i++) {
+ unsigned long long p;
+
+ p = bucket_percentage(atomic64_read(&pblk->pad_dist[i]),
+ total);
+ sz += snprintf(page + sz, PAGE_SIZE - sz, "%d:%lld%% ",
+ i + 1, p);
+ }
+ sz += snprintf(page + sz, PAGE_SIZE - sz, "\n");
+
+ return sz;
+}
+
#ifdef CONFIG_NVM_DEBUG
static ssize_t pblk_sysfs_stats_debug(struct pblk *pblk, char *page)
{
return snprintf(page, PAGE_SIZE,
- "%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\n",
+ "%lu\t%lu\t%ld\t%llu\t%ld\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\t%lu\n",
atomic_long_read(&pblk->inflight_writes),
atomic_long_read(&pblk->inflight_reads),
atomic_long_read(&pblk->req_writes),
- atomic_long_read(&pblk->nr_flush),
+ (u64)atomic64_read(&pblk->nr_flush),
atomic_long_read(&pblk->padded_writes),
atomic_long_read(&pblk->padded_wb),
atomic_long_read(&pblk->sub_writes),
@@ -426,6 +473,32 @@ static ssize_t pblk_sysfs_set_write_amp_trip(struct pblk *pblk,
}
+static ssize_t pblk_sysfs_set_padding_dist(struct pblk *pblk,
+ const char *page, size_t len)
+{
+ size_t c_len;
+ int reset_value;
+ int buckets = pblk->min_write_pgs - 1;
+ int i;
+
+ c_len = strcspn(page, "\n");
+ if (c_len >= len)
+ return -EINVAL;
+
+ if (kstrtouint(page, 0, &reset_value))
+ return -EINVAL;
+
+ if (reset_value != 0)
+ return -EINVAL;
+
+ for (i = 0; i < buckets; i++)
+ atomic64_set(&pblk->pad_dist[i], 0);
+
+ pblk->nr_flush_rst = atomic64_read(&pblk->nr_flush);
+
+ return len;
+}
+
static struct attribute sys_write_luns = {
.name = "write_luns",
.mode = 0444,
@@ -486,6 +559,11 @@ static struct attribute sys_write_amp_trip = {
.mode = 0644,
};
+static struct attribute sys_padding_dist = {
+ .name = "padding_dist",
+ .mode = 0644,
+};
+
#ifdef CONFIG_NVM_DEBUG
static struct attribute sys_stats_debug_attr = {
.name = "stats",
@@ -506,6 +584,7 @@ static struct attribute *pblk_attrs[] = {
&sys_lines_info_attr,
&sys_write_amp_mileage,
&sys_write_amp_trip,
+ &sys_padding_dist,
#ifdef CONFIG_NVM_DEBUG
&sys_stats_debug_attr,
#endif
@@ -539,6 +618,8 @@ static ssize_t pblk_sysfs_show(struct kobject *kobj, struct attribute *attr,
return pblk_sysfs_get_write_amp_mileage(pblk, buf);
else if (strcmp(attr->name, "write_amp_trip") == 0)
return pblk_sysfs_get_write_amp_trip(pblk, buf);
+ else if (strcmp(attr->name, "padding_dist") == 0)
+ return pblk_sysfs_get_padding_dist(pblk, buf);
#ifdef CONFIG_NVM_DEBUG
else if (strcmp(attr->name, "stats") == 0)
return pblk_sysfs_stats_debug(pblk, buf);
@@ -557,6 +638,8 @@ static ssize_t pblk_sysfs_store(struct kobject *kobj, struct attribute *attr,
return pblk_sysfs_set_sec_per_write(pblk, buf, len);
else if (strcmp(attr->name, "write_amp_trip") == 0)
return pblk_sysfs_set_write_amp_trip(pblk, buf, len);
+ else if (strcmp(attr->name, "padding_dist") == 0)
+ return pblk_sysfs_set_padding_dist(pblk, buf, len);
return 0;
}
diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
index 4b7d8618631f..17e2f242f7da 100644
--- a/drivers/lightnvm/pblk.h
+++ b/drivers/lightnvm/pblk.h
@@ -626,12 +626,16 @@ struct pblk {
u64 gc_rst_wa;
u64 pad_rst_wa;
+ /* Counters used for calculating padding distribution */
+ atomic64_t *pad_dist; /* Padding distribution buckets */
+ u64 nr_flush_rst; /* Flushes reset value for pad dist.*/
+ atomic64_t nr_flush; /* Number of flush/fua I/O */
+
#ifdef CONFIG_NVM_DEBUG
/* Non-persistent debug counters, 4kb sector I/Os */
atomic_long_t inflight_writes; /* Inflight writes (user and gc) */
atomic_long_t padded_writes; /* Sectors padded due to flush/fua */
atomic_long_t padded_wb; /* Sectors padded in write buffer */
- atomic_long_t nr_flush; /* Number of flush/fua I/O */
atomic_long_t req_writes; /* Sectors stored on write buffer */
atomic_long_t sub_writes; /* Sectors submitted from buffer */
atomic_long_t sync_writes; /* Sectors synced to media */
--
2.11.0
next prev parent reply other threads:[~2018-03-29 22:15 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-29 22:04 [GIT PULL 00/37] lightnvm patches for 4.17 Matias Bjørling
2018-03-29 22:04 ` [GIT PULL 01/37] lightnvm/pblk-gc: Delete an error message for a failed memory allocation in pblk_gc_line_prepare_ws() Matias Bjørling
2018-03-29 22:04 ` [GIT PULL 02/37] lightnvm: remove chnl_offset in nvme_nvm_identity Matias Bjørling
2018-03-29 22:04 ` [GIT PULL 03/37] lightnvm: pblk: handle bad sectors in the emeta area correctly Matias Bjørling
2018-03-29 22:04 ` [GIT PULL 04/37] lightnvm: pblk: check data lines version on recovery Matias Bjørling
2018-03-29 22:04 ` [GIT PULL 05/37] lightnvm: pblk: export write amplification counters to sysfs Matias Bjørling
2018-03-29 22:04 ` [GIT PULL 06/37] lightnvm: remove mlc pairs structure Matias Bjørling
2018-03-29 22:04 ` [GIT PULL 07/37] lightnvm: remove multiple groups in 1.2 data structure Matias Bjørling
2018-03-29 22:04 ` Matias Bjørling [this message]
2018-03-29 22:04 ` [GIT PULL 09/37] lightnvm: pblk: delete writer kick timer before stopping thread Matias Bjørling
2018-03-29 22:04 ` [GIT PULL 10/37] lightnvm: pblk: allow allocation of new lines during shutdown Matias Bjørling
2018-03-29 22:04 ` [GIT PULL 11/37] lightnvm: pblk: prevent race in pblk_rb_flush_point_set Matias Bjørling
2018-03-29 22:04 ` [GIT PULL 12/37] lightnvm: pblk: refactor bad block identification Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 13/37] lightnvm: make 1.2 data structures explicit Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 14/37] lightnvm: flatten nvm_id_group into nvm_id Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 15/37] lightnvm: add 2.0 geometry identification Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 16/37] lightnvm: remove max_rq_size Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 17/37] lightnvm: remove nvm_dev_ops->max_phys_sect Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 18/37] nvme: lightnvm: add late setup of block size and metadata Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 19/37] lightnvm: fix bad block initialization Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 20/37] lightnvm: centralize permission check for lightnvm ioctl Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 21/37] lightnvm: Avoid validation of default op value Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 22/37] lightnvm: pblk: refactor init/exit sequences Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 23/37] lightnvm: simplify geometry structure Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 24/37] lightnvm: add minor version to generic geometry Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 25/37] lightnvm: add shorten OCSSD version in geo Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 26/37] lightnvm: complete geo structure with maxoc* Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 27/37] lightnvm: normalize geometry nomenclature Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 28/37] lightnvm: add support for 2.0 address format Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 29/37] lightnvm: make address conversions depend on generic device Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 30/37] lightnvm: implement get log report chunk helpers Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 31/37] lightnvm: pblk: check for supported version Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 32/37] lightnvm: pblk: rename ppaf* to addrf* Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 33/37] lightnvm: pblk: implement get log report chunk Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 34/37] lightnvm: pblk: implement 2.0 support Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 35/37] lightnvm: pblk: don't recover unwritten lines Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 36/37] lightnvm: pblk: remove some unnecessary NULL checks Matias Bjørling
2018-03-29 22:05 ` [GIT PULL 37/37] lightnvm: remove function name in strings Matias Bjørling
2018-03-29 23:30 ` [GIT PULL 00/37] lightnvm patches for 4.17 Jens Axboe
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