@@ -63,6 +63,8 @@ int pblk_write_to_cache(struct pblk *pblk, struct bio *bio, unsigned long flags)
bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
}
+ atomic64_add(nr_entries, &pblk->user_wa);
+
#ifdef CONFIG_NVM_DEBUG
atomic_long_add(nr_entries, &pblk->inflight_writes);
atomic_long_add(nr_entries, &pblk->req_writes);
@@ -117,6 +119,8 @@ int pblk_write_gc_to_cache(struct pblk *pblk, struct pblk_gc_rq *gc_rq)
WARN_ONCE(gc_rq->secs_to_gc != valid_entries,
"pblk: inconsistent GC write\n");
+ atomic64_add(valid_entries, &pblk->gc_wa);
+
#ifdef CONFIG_NVM_DEBUG
atomic_long_add(valid_entries, &pblk->inflight_writes);
atomic_long_add(valid_entries, &pblk->recov_gc_writes);
@@ -1630,11 +1630,16 @@ void pblk_line_close_meta(struct pblk *pblk, struct pblk_line *line)
struct pblk_line_meta *lm = &pblk->lm;
struct pblk_emeta *emeta = line->emeta;
struct line_emeta *emeta_buf = emeta->buf;
+ struct wa_counters *wa = emeta_to_wa(lm, emeta_buf);
/* No need for exact vsc value; avoid a big line lock and take aprox. */
memcpy(emeta_to_vsc(pblk, emeta_buf), l_mg->vsc_list, lm->vsc_list_len);
memcpy(emeta_to_bb(emeta_buf), line->blk_bitmap, lm->blk_bitmap_len);
+ wa->user = cpu_to_le64(atomic64_read(&pblk->user_wa));
+ wa->pad = cpu_to_le64(atomic64_read(&pblk->pad_wa));
+ wa->gc = cpu_to_le64(atomic64_read(&pblk->gc_wa));
+
emeta_buf->nr_valid_lbas = cpu_to_le64(line->nr_valid_lbas);
emeta_buf->crc = cpu_to_le32(pblk_calc_emeta_crc(pblk, emeta_buf));
@@ -1837,6 +1842,7 @@ void pblk_update_map_dev(struct pblk *pblk, sector_t lba,
#endif
/* Invalidate and discard padded entries */
if (lba == ADDR_EMPTY) {
+ atomic64_inc(&pblk->pad_wa);
#ifdef CONFIG_NVM_DEBUG
atomic_long_inc(&pblk->padded_wb);
#endif
@@ -559,8 +559,8 @@ static unsigned int calc_emeta_len(struct pblk *pblk)
/* Round to sector size so that lba_list starts on its own sector */
lm->emeta_sec[1] = DIV_ROUND_UP(
- sizeof(struct line_emeta) + lm->blk_bitmap_len,
- geo->sec_size);
+ sizeof(struct line_emeta) + lm->blk_bitmap_len +
+ sizeof(struct wa_counters), geo->sec_size);
lm->emeta_len[1] = lm->emeta_sec[1] * geo->sec_size;
/* Round to sector size so that vsc_list starts on its own sector */
@@ -991,6 +991,13 @@ static void *pblk_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
if (flags & NVM_TARGET_FACTORY)
pblk_setup_uuid(pblk);
+ atomic64_set(&pblk->user_wa, 0);
+ atomic64_set(&pblk->pad_wa, 0);
+ atomic64_set(&pblk->gc_wa, 0);
+ pblk->user_rst_wa = 0;
+ pblk->pad_rst_wa = 0;
+ pblk->gc_rst_wa = 0;
+
#ifdef CONFIG_NVM_DEBUG
atomic_long_set(&pblk->inflight_writes, 0);
atomic_long_set(&pblk->padded_writes, 0);
@@ -65,6 +65,8 @@ static void pblk_map_page_data(struct pblk *pblk, unsigned int sentry,
lba_list[paddr] = cpu_to_le64(w_ctx->lba);
if (lba_list[paddr] != addr_empty)
line->nr_valid_lbas++;
+ else
+ atomic64_inc(&pblk->pad_wa);
} else {
lba_list[paddr] = meta_list[i].lba = addr_empty;
__pblk_map_invalidate(pblk, line, paddr);
@@ -622,6 +622,9 @@ unsigned int pblk_rb_read_to_bio(struct pblk_rb *rb, struct nvm_rq *rqd,
}
}
+ 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);
@@ -845,6 +845,29 @@ static int pblk_recov_check_line_version(struct pblk *pblk,
return 0;
}
+static void pblk_recov_wa_counters(struct pblk *pblk,
+ struct line_emeta *emeta)
+{
+ struct pblk_line_meta *lm = &pblk->lm;
+ struct line_header *header = &emeta->header;
+ struct wa_counters *wa = emeta_to_wa(lm, emeta);
+
+ /* WA counters were introduced in emeta version 0.2 */
+ if (header->version_major > 0 || header->version_minor >= 2) {
+ u64 user = le64_to_cpu(wa->user);
+ u64 pad = le64_to_cpu(wa->pad);
+ u64 gc = le64_to_cpu(wa->gc);
+
+ atomic64_set(&pblk->user_wa, user);
+ atomic64_set(&pblk->pad_wa, pad);
+ atomic64_set(&pblk->gc_wa, gc);
+
+ pblk->user_rst_wa = user;
+ pblk->pad_rst_wa = pad;
+ pblk->gc_rst_wa = gc;
+ }
+}
+
struct pblk_line *pblk_recov_l2p(struct pblk *pblk)
{
struct pblk_line_meta *lm = &pblk->lm;
@@ -965,6 +988,8 @@ struct pblk_line *pblk_recov_l2p(struct pblk *pblk)
if (pblk_recov_check_line_version(pblk, line->emeta->buf))
return ERR_PTR(-EINVAL);
+ pblk_recov_wa_counters(pblk, line->emeta->buf);
+
if (pblk_recov_l2p_from_emeta(pblk, line))
pblk_recov_l2p_from_oob(pblk, line);
@@ -298,6 +298,49 @@ static ssize_t pblk_sysfs_get_sec_per_write(struct pblk *pblk, char *page)
return snprintf(page, PAGE_SIZE, "%d\n", pblk->sec_per_write);
}
+static ssize_t pblk_get_write_amp(u64 user, u64 gc, u64 pad,
+ char *page)
+{
+ int sz;
+
+ sz = snprintf(page, PAGE_SIZE,
+ "user:%lld gc:%lld pad:%lld WA:",
+ user, gc, pad);
+
+ if (!user) {
+ sz += snprintf(page + sz, PAGE_SIZE - sz, "NaN\n");
+ } else {
+ u64 wa_int, wa_frac, wa_frac_int;
+
+ wa_int = user + gc + pad;
+ sector_div(wa_int, user);
+
+ wa_frac_int = (user + gc + pad) * 100000;
+ sector_div(wa_frac_int, user);
+ div_u64_rem(wa_frac_int, 100000, (u32 *)&wa_frac);
+
+ sz += snprintf(page + sz, PAGE_SIZE - sz, "%lld.%05lld\n",
+ wa_int, wa_frac);
+ }
+
+ return sz;
+}
+
+static ssize_t pblk_sysfs_get_write_amp_mileage(struct pblk *pblk, char *page)
+{
+ return pblk_get_write_amp(atomic64_read(&pblk->user_wa),
+ atomic64_read(&pblk->gc_wa), atomic64_read(&pblk->pad_wa),
+ page);
+}
+
+static ssize_t pblk_sysfs_get_write_amp_trip(struct pblk *pblk, char *page)
+{
+ return pblk_get_write_amp(
+ atomic64_read(&pblk->user_wa) - pblk->user_rst_wa,
+ atomic64_read(&pblk->gc_wa) - pblk->gc_rst_wa,
+ atomic64_read(&pblk->pad_wa) - pblk->pad_rst_wa, page);
+}
+
#ifdef CONFIG_NVM_DEBUG
static ssize_t pblk_sysfs_stats_debug(struct pblk *pblk, char *page)
{
@@ -360,6 +403,30 @@ static ssize_t pblk_sysfs_set_sec_per_write(struct pblk *pblk,
return len;
}
+static ssize_t pblk_sysfs_set_write_amp_trip(struct pblk *pblk,
+ const char *page, size_t len)
+{
+ size_t c_len;
+ int reset_value;
+
+ 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;
+
+ pblk->user_rst_wa = atomic64_read(&pblk->user_wa);
+ pblk->pad_rst_wa = atomic64_read(&pblk->pad_wa);
+ pblk->gc_rst_wa = atomic64_read(&pblk->gc_wa);
+
+ return len;
+}
+
+
static struct attribute sys_write_luns = {
.name = "write_luns",
.mode = 0444,
@@ -410,6 +477,16 @@ static struct attribute sys_max_sec_per_write = {
.mode = 0644,
};
+static struct attribute sys_write_amp_mileage = {
+ .name = "write_amp_mileage",
+ .mode = 0444,
+};
+
+static struct attribute sys_write_amp_trip = {
+ .name = "write_amp_trip",
+ .mode = 0644,
+};
+
#ifdef CONFIG_NVM_DEBUG
static struct attribute sys_stats_debug_attr = {
.name = "stats",
@@ -428,6 +505,8 @@ static struct attribute *pblk_attrs[] = {
&sys_stats_ppaf_attr,
&sys_lines_attr,
&sys_lines_info_attr,
+ &sys_write_amp_mileage,
+ &sys_write_amp_trip,
#ifdef CONFIG_NVM_DEBUG
&sys_stats_debug_attr,
#endif
@@ -457,6 +536,10 @@ static ssize_t pblk_sysfs_show(struct kobject *kobj, struct attribute *attr,
return pblk_sysfs_lines_info(pblk, buf);
else if (strcmp(attr->name, "max_sec_per_write") == 0)
return pblk_sysfs_get_sec_per_write(pblk, buf);
+ else if (strcmp(attr->name, "write_amp_mileage") == 0)
+ 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);
#ifdef CONFIG_NVM_DEBUG
else if (strcmp(attr->name, "stats") == 0)
return pblk_sysfs_stats_debug(pblk, buf);
@@ -473,7 +556,8 @@ static ssize_t pblk_sysfs_store(struct kobject *kobj, struct attribute *attr,
return pblk_sysfs_gc_force(pblk, buf, len);
else if (strcmp(attr->name, "max_sec_per_write") == 0)
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);
return 0;
}
@@ -331,7 +331,7 @@ enum {
#define SMETA_VERSION_MINOR (1)
#define EMETA_VERSION_MAJOR (0)
-#define EMETA_VERSION_MINOR (1)
+#define EMETA_VERSION_MINOR (2)
struct line_header {
__le32 crc;
@@ -361,11 +361,13 @@ struct line_smeta {
__le64 lun_bitmap[];
};
+
/*
* Metadata layout in media:
* First sector:
* 1. struct line_emeta
* 2. bad block bitmap (u64 * window_wr_lun)
+ * 3. write amplification counters
* Mid sectors (start at lbas_sector):
* 3. nr_lbas (u64) forming lba list
* Last sectors (start at vsc_sector):
@@ -389,7 +391,15 @@ struct line_emeta {
__le32 next_id; /* Line id for next line */
__le64 nr_lbas; /* Number of lbas mapped in line */
__le64 nr_valid_lbas; /* Number of valid lbas mapped in line */
- __le64 bb_bitmap[]; /* Updated bad block bitmap for line */
+ __le64 bb_bitmap[]; /* Updated bad block bitmap for line */
+};
+
+
+/* Write amplification counters stored on media */
+struct wa_counters {
+ __le64 user; /* Number of user written sectors */
+ __le64 gc; /* Number of sectors written by GC*/
+ __le64 pad; /* Number of padded sectors */
};
struct pblk_emeta {
@@ -519,10 +529,11 @@ struct pblk_line_meta {
unsigned int smeta_sec; /* Sectors needed for smeta */
unsigned int emeta_len[4]; /* Lengths for emeta:
- * [0]: Total length
- * [1]: struct line_emeta length
- * [2]: L2P portion length
- * [3]: vsc list length
+ * [0]: Total
+ * [1]: struct line_emeta +
+ * bb_bitmap + struct wa_counters
+ * [2]: L2P portion
+ * [3]: vsc
*/
unsigned int emeta_sec[4]; /* Sectors needed for emeta. Same layout
* as emeta_len
@@ -604,8 +615,19 @@ struct pblk {
int sec_per_write;
unsigned char instance_uuid[16];
+
+ /* Persistent write amplification counters, 4kb sector I/Os */
+ atomic64_t user_wa; /* Sectors written by user */
+ atomic64_t gc_wa; /* Sectors written by GC */
+ atomic64_t pad_wa; /* Padded sectors written */
+
+ /* Reset values for delta write amplification measurements */
+ u64 user_rst_wa;
+ u64 gc_rst_wa;
+ u64 pad_rst_wa;
+
#ifdef CONFIG_NVM_DEBUG
- /* All debug counters apply to 4kb sector I/Os */
+ /* 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 */
@@ -900,6 +922,12 @@ static inline void *emeta_to_bb(struct line_emeta *emeta)
return emeta->bb_bitmap;
}
+static inline void *emeta_to_wa(struct pblk_line_meta *lm,
+ struct line_emeta *emeta)
+{
+ return emeta->bb_bitmap + lm->blk_bitmap_len;
+}
+
static inline void *emeta_to_lbas(struct pblk *pblk, struct line_emeta *emeta)
{
return ((void *)emeta + pblk->lm.emeta_len[1]);