From: Paul HENRYS <paul.henrysd@gmail.com>
To: richard@nod.at, miquel.raynal@bootlin.com, vigneshr@ti.com
Cc: linux-mtd@lists.infradead.org, Paul HENRYS <paul.henrysd@gmail.com>
Subject: [PATCH] ubi: Update mean Erase Counter calculation at run-time
Date: Thu, 2 Jan 2020 13:29:00 +0100 [thread overview]
Message-ID: <1577968140-11528-1-git-send-email-paul.henrysd@gmail.com> (raw)
The mean EC value was only calculated when attaching a UBI device
but not updated afterwards. A new parameter is added to the struct
ubi_device to keep track of the sum of the erase counters of all
eraseblocks for a UBI device while they are erased and potentially
become bad. The mean EC is then calculated on request when reading
the "mean_ec" sysfs file of a UBI device.
Signed-off-by: Paul HENRYS <paul.henrysd@gmail.com>
---
drivers/mtd/ubi/build.c | 10 ++++++++++
drivers/mtd/ubi/ubi.h | 3 ++-
drivers/mtd/ubi/wl.c | 5 +++++
3 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index d636bbe..3291fa4 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -126,6 +126,8 @@ static struct device_attribute dev_volumes_count =
__ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_max_ec =
__ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_mean_ec =
+ __ATTR(mean_ec, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_reserved_for_bad =
__ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_bad_peb_count =
@@ -364,6 +366,13 @@ static ssize_t dev_attribute_show(struct device *dev,
ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
else if (attr == &dev_max_ec)
ret = sprintf(buf, "%d\n", ubi->max_ec);
+ else if (attr == &dev_mean_ec) {
+ /* Calculate mean erase counter */
+ if (ubi->good_peb_count)
+ ubi->mean_ec = div_u64(ubi->ec_sum,
+ ubi->good_peb_count);
+ ret = sprintf(buf, "%d\n", ubi->mean_ec);
+ }
else if (attr == &dev_reserved_for_bad)
ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
else if (attr == &dev_bad_peb_count)
@@ -391,6 +400,7 @@ static struct attribute *ubi_dev_attrs[] = {
&dev_total_eraseblocks.attr,
&dev_volumes_count.attr,
&dev_max_ec.attr,
+ &dev_mean_ec.attr,
&dev_reserved_for_bad.attr,
&dev_bad_peb_count.attr,
&dev_max_vol_count.attr,
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index 9688b41..d796217 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -472,6 +472,7 @@ struct ubi_debug_info {
*
* @max_ec: current highest erase counter value
* @mean_ec: current mean erase counter value
+ * @ec_sum: a temporary variable used when calculating @mean_ec
*
* @global_sqnum: global sequence number
* @ltree_lock: protects the lock tree and @global_sqnum
@@ -580,8 +581,8 @@ struct ubi_device {
struct mutex device_mutex;
int max_ec;
- /* Note, mean_ec is not updated run-time - should be fixed */
int mean_ec;
+ uint64_t ec_sum;
/* EBA sub-system's stuff */
unsigned long long global_sqnum;
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 5d77a38..24c47ce 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -442,6 +442,7 @@ static int sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e,
int err;
struct ubi_ec_hdr *ec_hdr;
unsigned long long ec = e->ec;
+ unsigned long long erasecycle;
dbg_wl("erase PEB %d, old EC %llu", e->pnum, ec);
@@ -458,6 +459,7 @@ static int sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e,
goto out_free;
ec += err;
+ erasecycle = err;
if (ec > UBI_MAX_ERASECOUNTER) {
/*
* Erase counter overflow. Upgrade UBI and use 64-bit
@@ -479,6 +481,7 @@ static int sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e,
e->ec = ec;
spin_lock(&ubi->wl_lock);
+ ubi->ec_sum += erasecycle;
if (e->ec > ubi->max_ec)
ubi->max_ec = e->ec;
spin_unlock(&ubi->wl_lock);
@@ -1164,6 +1167,7 @@ static int __erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk)
}
ubi->bad_peb_count += 1;
ubi->good_peb_count -= 1;
+ ubi->ec_sum -= e->ec;
ubi_calculate_reserved(ubi);
if (available_consumed)
ubi_warn(ubi, "no PEBs in the reserved pool, used an available PEB");
@@ -1738,6 +1742,7 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai)
mutex_init(&ubi->move_mutex);
init_rwsem(&ubi->work_sem);
ubi->max_ec = ai->max_ec;
+ ubi->ec_sum = ai->ec_sum;
INIT_LIST_HEAD(&ubi->works);
sprintf(ubi->bgt_name, UBI_BGT_NAME_PATTERN, ubi->ubi_num);
--
2.7.4
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next reply other threads:[~2020-01-02 12:30 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-02 12:29 Paul HENRYS [this message]
2020-01-12 23:05 ` [PATCH] ubi: Update mean Erase Counter calculation at run-time Richard Weinberger
2020-01-13 12:50 ` Paul HENRYS d'AUBIGNY
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