A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-29 03:01:39 -04:00
Code Issues Projects Releases Packages Wiki Activity

block: make /sys/block/<dev>/queue/discard_max_bytes writeable

Browse source 
Lots of devices support huge discard sizes these days. Depending
on how the device handles them internally, huge discards can
introduce massive latencies (hundreds of msec) on the device side.

We have a sysfs file, discard_max_bytes, that advertises the max
hardware supported discard size. Make this writeable, and split
the settings into a soft and hard limit. This can be set from
'discard_granularity' and up to the hardware limit.

Add a new sysfs file, 'discard_max_hw_bytes', that shows the hw
set limit.

Reviewed-by: Jeff Moyer <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
This commit is contained in:
Jens Axboe 2015-07-16 09:14:26 -06:00
commit 0034af0365
4 changed files with 53 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

40
block/blk-sysfs.c
View file

@ -145,12 +145,43 @@ static ssize_t queue_discard_granularity_show(struct request_queue *q, char *pag
return queue_var_show(q->limits.discard_granularity, page);
}
static ssize_t queue_discard_max_hw_show(struct request_queue *q, char *page)
{
unsigned long long val;
val = q->limits.max_hw_discard_sectors << 9;
return sprintf(page, "%llu\n", val);
}
static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
{
return sprintf(page, "%llu\n",
(unsigned long long)q->limits.max_discard_sectors << 9);
}
static ssize_t queue_discard_max_store(struct request_queue *q,
const char *page, size_t count)
{
unsigned long max_discard;
ssize_t ret = queue_var_store(&max_discard, page, count);
if (ret < 0)
return ret;
if (max_discard & (q->limits.discard_granularity - 1))
return -EINVAL;
max_discard >>= 9;
if (max_discard > UINT_MAX)
return -EINVAL;
if (max_discard > q->limits.max_hw_discard_sectors)
max_discard = q->limits.max_hw_discard_sectors;
q->limits.max_discard_sectors = max_discard;
return ret;
}
static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
{
return queue_var_show(queue_discard_zeroes_data(q), page);
@ -360,9 +391,15 @@ static struct queue_sysfs_entry queue_discard_granularity_entry = {
.show = queue_discard_granularity_show,
};
static struct queue_sysfs_entry queue_discard_max_hw_entry = {
.attr = {.name = "discard_max_hw_bytes", .mode = S_IRUGO },
.show = queue_discard_max_hw_show,
};
static struct queue_sysfs_entry queue_discard_max_entry = {
.attr = {.name = "discard_max_bytes", .mode = S_IRUGO },
.attr = {.name = "discard_max_bytes", .mode = S_IRUGO | S_IWUSR },
.show = queue_discard_max_show,
.store = queue_discard_max_store,
};
static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
@ -421,6 +458,7 @@ static struct attribute *default_attrs[] = {
&queue_io_opt_entry.attr,
&queue_discard_granularity_entry.attr,
&queue_discard_max_entry.attr,
&queue_discard_max_hw_entry.attr,
&queue_discard_zeroes_data_entry.attr,
&queue_write_same_max_entry.attr,
&queue_nonrot_entry.attr,