Unaligned I/O statistics added

git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@6208 d57e44dd-8a1f-0410-8b47-8ef2f437770f
2026-05-21 20:51:27 +00:00 · 2015-05-21 01:28:58 +00:00
parent dd3799d62a
commit a422ba3cc9
5 changed files with 64 additions and 7 deletions
--- a/scst/README
+++ b/scst/README
@@ -665,6 +665,20 @@ Every target should have at least the following entries:
   until rel_tgt_id becomes unique. This attribute initialized unique by
   SCST by default.

+ - *count*, e.g. read_io_count_kb, - statistics about executed
+   commands and transferred data. Those attributes have speaking names
+   built from parts:
+
+   1. Data transfer direction
+
+   2. Alignment type: not specified or unaligned (on 4K boundaries)
+
+   3. Type: IO (commands) count or amount of transferred data
+
+   4. For transferred data: measurement units
+
+   For instance, read_unaligned_cmd_count means number of 4K unaligned IOs.
+
 A target driver may have also the following entries:

 - "hw_target" - if the target driver supports both hardware and virtual
@@ -726,6 +740,9 @@ following entries:
 - latency - if CONFIG_SCST_MEASURE_LATENCY enabled, contains latency
   statistics for this session.

+ - *count*, e.g. read_io_count_kb, - statistics about executed
+   commands and transferred data. See above for more details.
+
 - luns - a link pointing out to the corresponding LUNs set (security
   group) where this session was attached to.

--- a/scst/README_in-tree
+++ b/scst/README_in-tree
@@ -541,6 +541,20 @@ Every target should have at least the following entries:
   until rel_tgt_id becomes unique. This attribute initialized unique by
   SCST by default.

+ - *count*, e.g. read_io_count_kb, - statistics about executed
+   commands and transferred data. Those attributes have speaking names
+   built from parts:
+
+   1. Data transfer direction
+
+   2. Alignment type: not specified or unaligned (on 4K boundaries)
+
+   3. Type: IO (commands) count or amount of transferred data
+
+   4. For transferred data: measurement units
+
+   For instance, read_unaligned_cmd_count means number of 4K unaligned IOs.
+
 A target driver may have also the following entries:

 - "hw_target" - if the target driver supports both hardware and virtual
@@ -602,6 +616,9 @@ following entries:
 - latency - if CONFIG_SCST_MEASURE_LATENCY enabled, contains latency
   statistics for this session.

+ - *count*, e.g. read_io_count_kb, - statistics about executed
+   commands and transferred data. See above for more details.
+
 - luns - a link pointing out to the corresponding LUNs set (security
   group) where this session was attached to.

--- a/scst/include/scst.h
+++ b/scst/include/scst.h
@@ -2039,6 +2039,7 @@ struct scst_ext_latency_stat {
 struct scst_io_stat_entry {
 	uint64_t cmd_count;
 	uint64_t io_byte_count;
+	uint64_t unaligned_cmd_count;
 };

 /*
--- a/scst/src/scst_sysfs.c
+++ b/scst/src/scst_sysfs.c
@@ -2757,14 +2757,14 @@ static struct kobj_attribute scst_tgt_##attr##_attr =			\

 SCST_TGT_SYSFS_STAT_ATTR(cmd_count, unknown_cmd_count, SCST_DATA_UNKNOWN, >> 0);
 SCST_TGT_SYSFS_STAT_ATTR(cmd_count, write_cmd_count, SCST_DATA_WRITE, >> 0);
-SCST_TGT_SYSFS_STAT_ATTR(io_byte_count, write_io_count_kb, SCST_DATA_WRITE,
-			 >> 10);
+SCST_TGT_SYSFS_STAT_ATTR(io_byte_count, write_io_count_kb, SCST_DATA_WRITE, >> 10);
+SCST_TGT_SYSFS_STAT_ATTR(unaligned_cmd_count, write_unaligned_cmd_count, SCST_DATA_WRITE, >> 0);
 SCST_TGT_SYSFS_STAT_ATTR(cmd_count, read_cmd_count, SCST_DATA_READ, >> 0);
-SCST_TGT_SYSFS_STAT_ATTR(io_byte_count, read_io_count_kb, SCST_DATA_READ,
-			 >> 10);
+SCST_TGT_SYSFS_STAT_ATTR(io_byte_count, read_io_count_kb, SCST_DATA_READ, >> 10);
+SCST_TGT_SYSFS_STAT_ATTR(unaligned_cmd_count, read_unaligned_cmd_count, SCST_DATA_READ, >> 0);
 SCST_TGT_SYSFS_STAT_ATTR(cmd_count, bidi_cmd_count, SCST_DATA_BIDI, >> 0);
-SCST_TGT_SYSFS_STAT_ATTR(io_byte_count, bidi_io_count_kb, SCST_DATA_BIDI,
-			 >> 10);
+SCST_TGT_SYSFS_STAT_ATTR(io_byte_count, bidi_io_count_kb, SCST_DATA_BIDI, >> 10);
+SCST_TGT_SYSFS_STAT_ATTR(unaligned_cmd_count, bidi_unaligned_cmd_count, SCST_DATA_BIDI, >> 0);
 SCST_TGT_SYSFS_STAT_ATTR(cmd_count, none_cmd_count, SCST_DATA_NONE, >> 0);

 static struct attribute *scst_tgt_attrs[] = {
@@ -2777,10 +2777,13 @@ static struct attribute *scst_tgt_attrs[] = {
 	&scst_tgt_unknown_cmd_count_attr.attr,
 	&scst_tgt_write_cmd_count_attr.attr,
 	&scst_tgt_write_io_count_kb_attr.attr,
+	&scst_tgt_write_unaligned_cmd_count_attr.attr,
 	&scst_tgt_read_cmd_count_attr.attr,
 	&scst_tgt_read_io_count_kb_attr.attr,
+	&scst_tgt_read_unaligned_cmd_count_attr.attr,
 	&scst_tgt_bidi_cmd_count_attr.attr,
 	&scst_tgt_bidi_io_count_kb_attr.attr,
+	&scst_tgt_bidi_unaligned_cmd_count_attr.attr,
 	&scst_tgt_none_cmd_count_attr.attr,
 	NULL,
 };
@@ -4568,6 +4571,7 @@ static ssize_t scst_sess_sysfs_##exported_name##_store(struct kobject *kobj,	\
 	BUILD_BUG_ON(dir >= SCST_DATA_DIR_MAX);					\
 	sess->io_stats[dir].cmd_count = 0;					\
 	sess->io_stats[dir].io_byte_count = 0;					\
+	sess->io_stats[dir].unaligned_cmd_count = 0;				\
 	spin_unlock_irq(&sess->sess_list_lock);					\
 	return count;								\
 }										\
@@ -4580,13 +4584,15 @@ static struct kobj_attribute session_##exported_name##_attr =			\
 SCST_SESS_SYSFS_STAT_ATTR(cmd_count, unknown_cmd_count, SCST_DATA_UNKNOWN, 0);
 SCST_SESS_SYSFS_STAT_ATTR(cmd_count, write_cmd_count, SCST_DATA_WRITE, 0);
 SCST_SESS_SYSFS_STAT_ATTR(io_byte_count, write_io_count_kb, SCST_DATA_WRITE, 1);
+SCST_SESS_SYSFS_STAT_ATTR(unaligned_cmd_count, write_unaligned_cmd_count, SCST_DATA_WRITE, 0);
 SCST_SESS_SYSFS_STAT_ATTR(cmd_count, read_cmd_count, SCST_DATA_READ, 0);
 SCST_SESS_SYSFS_STAT_ATTR(io_byte_count, read_io_count_kb, SCST_DATA_READ, 1);
+SCST_SESS_SYSFS_STAT_ATTR(unaligned_cmd_count, read_unaligned_cmd_count, SCST_DATA_READ, 0);
 SCST_SESS_SYSFS_STAT_ATTR(cmd_count, bidi_cmd_count, SCST_DATA_BIDI, 0);
 SCST_SESS_SYSFS_STAT_ATTR(io_byte_count, bidi_io_count_kb, SCST_DATA_BIDI, 1);
+SCST_SESS_SYSFS_STAT_ATTR(unaligned_cmd_count, bidi_unaligned_cmd_count, SCST_DATA_BIDI, 0);
 SCST_SESS_SYSFS_STAT_ATTR(cmd_count, none_cmd_count, SCST_DATA_NONE, 0);

-
 static ssize_t scst_sess_force_close_store(struct kobject *kobj,
 					   struct kobj_attribute *attr,
 					   const char *buf, size_t count)
@@ -4615,10 +4621,13 @@ static struct attribute *scst_session_attrs[] = {
 	&session_unknown_cmd_count_attr.attr,
 	&session_write_cmd_count_attr.attr,
 	&session_write_io_count_kb_attr.attr,
+	&session_write_unaligned_cmd_count_attr.attr,
 	&session_read_cmd_count_attr.attr,
 	&session_read_io_count_kb_attr.attr,
+	&session_read_unaligned_cmd_count_attr.attr,
 	&session_bidi_cmd_count_attr.attr,
 	&session_bidi_io_count_kb_attr.attr,
+	&session_bidi_unaligned_cmd_count_attr.attr,
 	&session_none_cmd_count_attr.attr,
 #ifdef CONFIG_SCST_MEASURE_LATENCY
 	&session_latency_attr.attr,
--- a/scst/src/scst_targ.c
+++ b/scst/src/scst_targ.c
@@ -4165,6 +4165,7 @@ static int scst_finish_cmd(struct scst_cmd *cmd)
 	int res;
 	struct scst_session *sess = cmd->sess;
 	struct scst_io_stat_entry *stat;
+	int block_shift, align_len;

 	TRACE_ENTRY();

@@ -4193,6 +4194,18 @@ static int scst_finish_cmd(struct scst_cmd *cmd)
 	stat = &sess->io_stats[cmd->data_direction];
 	stat->cmd_count++;
 	stat->io_byte_count += cmd->bufflen + cmd->out_bufflen;
+	if (likely(cmd->dev != NULL)) {
+		block_shift = cmd->dev->block_shift;
+		/* Let's track only 4K unaligned cmds at the moment */
+		align_len = (block_shift != 0) ? 4095 : 0;
+	} else {
+		block_shift = 0;
+		align_len = 0;
+	}
+
+	if (unlikely(((cmd->lba << block_shift) & align_len) != 0) ||
+	    unlikely(((cmd->bufflen + cmd->out_bufflen) & align_len) != 0))
+		stat->unaligned_cmd_count++;

 	list_del(&cmd->sess_cmd_list_entry);