[PATCH] xen-blkback: make st_ statistics per ring

From: Bob Liu
Date: Tue Dec 08 2015 - 18:44:42 EST

Next message: Colin King: "[PATCH] ath9k: fix inconsistent indenting on return statement"
Previous message: Lloyds TSB Bank PLC: "lÃnetilbud"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

Make st_* statistics per ring and the VBD sysfs would iterate over all the
rings.

Note: xenvbd_sysfs_delif() is called in xen_blkbk_remove() before all rings
are torn down, so it's safe.

This patch was based on konrad/xen.git/for-jens-4.5.

Signed-off-by: Bob Liu <bob.liu@xxxxxxxxxx>
---
drivers/block/xen-blkback/blkback.c | 34 +++++++++++++-------------
drivers/block/xen-blkback/common.h | 20 ++++++++--------
drivers/block/xen-blkback/xenbus.c | 45 +++++++++++++++++++++++++++--------
3 files changed, 61 insertions(+), 38 deletions(-)

diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index a00d6c6..ef358d7 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -587,20 +587,18 @@ irqreturn_t xen_blkif_be_int(int irq, void *dev_id)

static void print_stats(struct xen_blkif_ring *ring)
{
- struct xen_blkif *blkif = ring->blkif;
-
pr_info("(%s): oo %3llu | rd %4llu | wr %4llu | f %4llu"
" | ds %4llu | pg: %4u/%4d\n",
- current->comm, blkif->st_oo_req,
- blkif->st_rd_req, blkif->st_wr_req,
- blkif->st_f_req, blkif->st_ds_req,
+ current->comm, ring->st_oo_req,
+ ring->st_rd_req, ring->st_wr_req,
+ ring->st_f_req, ring->st_ds_req,
ring->persistent_gnt_c,
xen_blkif_max_pgrants);
- blkif->st_print = jiffies + msecs_to_jiffies(10 * 1000);
- blkif->st_rd_req = 0;
- blkif->st_wr_req = 0;
- blkif->st_oo_req = 0;
- blkif->st_ds_req = 0;
+ ring->st_print = jiffies + msecs_to_jiffies(10 * 1000);
+ ring->st_rd_req = 0;
+ ring->st_wr_req = 0;
+ ring->st_oo_req = 0;
+ ring->st_ds_req = 0;
}

int xen_blkif_schedule(void *arg)
@@ -655,7 +653,7 @@ purge_gnt_list:
/* Shrink if we have more than xen_blkif_max_buffer_pages */
shrink_free_pagepool(ring, xen_blkif_max_buffer_pages);

- if (log_stats && time_after(jiffies, ring->blkif->st_print))
+ if (log_stats && time_after(jiffies, ring->st_print))
print_stats(ring);
}

@@ -1017,7 +1015,7 @@ static int dispatch_discard_io(struct xen_blkif_ring *ring,
preq.sector_number + preq.nr_sects, blkif->vbd.pdevice);
goto fail_response;
}
- blkif->st_ds_req++;
+ ring->st_ds_req++;

secure = (blkif->vbd.discard_secure &&
(req->u.discard.flag & BLKIF_DISCARD_SECURE)) ?
@@ -1144,7 +1142,7 @@ __do_block_io_op(struct xen_blkif_ring *ring)

pending_req = alloc_req(ring);
if (NULL == pending_req) {
- ring->blkif->st_oo_req++;
+ ring->st_oo_req++;
more_to_do = 1;
break;
}
@@ -1242,17 +1240,17 @@ static int dispatch_rw_block_io(struct xen_blkif_ring *ring,

switch (req_operation) {
case BLKIF_OP_READ:
- ring->blkif->st_rd_req++;
+ ring->st_rd_req++;
operation = READ;
break;
case BLKIF_OP_WRITE:
- ring->blkif->st_wr_req++;
+ ring->st_wr_req++;
operation = WRITE_ODIRECT;
break;
case BLKIF_OP_WRITE_BARRIER:
drain = true;
case BLKIF_OP_FLUSH_DISKCACHE:
- ring->blkif->st_f_req++;
+ ring->st_f_req++;
operation = WRITE_FLUSH;
break;
default:
@@ -1394,9 +1392,9 @@ static int dispatch_rw_block_io(struct xen_blkif_ring *ring,
blk_finish_plug(&plug);

if (operation == READ)
- ring->blkif->st_rd_sect += preq.nr_sects;
+ ring->st_rd_sect += preq.nr_sects;
else if (operation & WRITE)
- ring->blkif->st_wr_sect += preq.nr_sects;
+ ring->st_wr_sect += preq.nr_sects;

return 0;

diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h
index 54f126e..2495bb3 100644
--- a/drivers/block/xen-blkback/common.h
+++ b/drivers/block/xen-blkback/common.h
@@ -298,6 +298,16 @@ struct xen_blkif_ring {
atomic_t persistent_gnt_in_use;
unsigned long next_lru;

+ /* statistics */
+ unsigned long st_print;
+ unsigned long long st_rd_req;
+ unsigned long long st_wr_req;
+ unsigned long long st_oo_req;
+ unsigned long long st_f_req;
+ unsigned long long st_ds_req;
+ unsigned long long st_rd_sect;
+ unsigned long long st_wr_sect;
+
/* Used by the kworker that offload work from the persistent purge. */
struct list_head persistent_purge_list;
struct work_struct persistent_purge_work;
@@ -328,16 +338,6 @@ struct xen_blkif {
struct completion drain_complete;
atomic_t drain;

- /* statistics */
- unsigned long st_print;
- unsigned long long st_rd_req;
- unsigned long long st_wr_req;
- unsigned long long st_oo_req;
- unsigned long long st_f_req;
- unsigned long long st_ds_req;
- unsigned long long st_rd_sect;
- unsigned long long st_wr_sect;
-
struct work_struct free_work;
unsigned int nr_ring_pages;
/* All rings for this device. */
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index c92b358..44396b8 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -159,6 +159,7 @@ static int xen_blkif_alloc_rings(struct xen_blkif *blkif)
init_waitqueue_head(&ring->pending_free_wq);
init_waitqueue_head(&ring->shutdown_wq);
ring->blkif = blkif;
+ ring->st_print = jiffies;
xen_blkif_get(blkif);
}

@@ -179,7 +180,6 @@ static struct xen_blkif *xen_blkif_alloc(domid_t domid)
atomic_set(&blkif->refcnt, 1);
init_completion(&blkif->drain_complete);
INIT_WORK(&blkif->free_work, xen_blkif_deferred_free);
- blkif->st_print = jiffies;

return blkif;
}
@@ -329,25 +329,38 @@ int __init xen_blkif_interface_init(void)
* sysfs interface for VBD I/O requests
*/

-#define VBD_SHOW(name, format, args...) \
+#define VBD_SHOW_ALLRING(name, format) \
static ssize_t show_##name(struct device *_dev, \
struct device_attribute *attr, \
char *buf) \
{ \
struct xenbus_device *dev = to_xenbus_device(_dev); \
struct backend_info *be = dev_get_drvdata(&dev->dev); \
+ struct xen_blkif *blkif = be->blkif; \
+ unsigned int i; \
+ unsigned long long result = 0; \
\
- return sprintf(buf, format, ##args); \
+ if (!blkif->rings) \
+ goto out; \
+ \
+ for (i = 0; i < blkif->nr_rings; i++) { \
+ struct xen_blkif_ring *ring = &blkif->rings[i]; \
+ \
+ result += ring->st_##name; \
+ } \
+ \
+out: \
+ return sprintf(buf, format, result); \
} \
static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)

-VBD_SHOW(oo_req, "%llu\n", be->blkif->st_oo_req);
-VBD_SHOW(rd_req, "%llu\n", be->blkif->st_rd_req);
-VBD_SHOW(wr_req, "%llu\n", be->blkif->st_wr_req);
-VBD_SHOW(f_req, "%llu\n", be->blkif->st_f_req);
-VBD_SHOW(ds_req, "%llu\n", be->blkif->st_ds_req);
-VBD_SHOW(rd_sect, "%llu\n", be->blkif->st_rd_sect);
-VBD_SHOW(wr_sect, "%llu\n", be->blkif->st_wr_sect);
+VBD_SHOW_ALLRING(oo_req, "%llu\n");
+VBD_SHOW_ALLRING(rd_req, "%llu\n");
+VBD_SHOW_ALLRING(wr_req, "%llu\n");
+VBD_SHOW_ALLRING(f_req, "%llu\n");
+VBD_SHOW_ALLRING(ds_req, "%llu\n");
+VBD_SHOW_ALLRING(rd_sect, "%llu\n");
+VBD_SHOW_ALLRING(wr_sect, "%llu\n");

static struct attribute *xen_vbdstat_attrs[] = {
&dev_attr_oo_req.attr,
@@ -365,6 +378,18 @@ static struct attribute_group xen_vbdstat_group = {
.attrs = xen_vbdstat_attrs,
};

+#define VBD_SHOW(name, format, args...) \
+ static ssize_t show_##name(struct device *_dev, \
+ struct device_attribute *attr, \
+ char *buf) \
+ { \
+ struct xenbus_device *dev = to_xenbus_device(_dev); \
+ struct backend_info *be = dev_get_drvdata(&dev->dev); \
+ \
+ return sprintf(buf, format, ##args); \
+ } \
+ static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
+
VBD_SHOW(physical_device, "%x:%x\n", be->major, be->minor);
VBD_SHOW(mode, "%s\n", be->mode);

--
1.7.10.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

Next message: Colin King: "[PATCH] ath9k: fix inconsistent indenting on return statement"
Previous message: Lloyds TSB Bank PLC: "lÃnetilbud"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]