1) Add ZRAM_MULTI_STREAM configuration option and make multi stream
zcomp support available.
2) Introduce zram device attribute max_comp_streams to show and store
current zcomp's max number of zcomp streams (num_strm).
3) Extend zcomp zcomp_create() with `num_strm' parameter. `num_strm'
limits the number of zcomp_strm structs in compression backend's idle
list (max_comp_streams).
If ZRAM_MULTI_STREAM option selected:
-- user can change max number of compression streams (max_comp_streams),
otherwise, attempt to change its default value (1) will be ignored.
-- passing to zcomp_create() num_strm equals to 1 will initialise zcomp
using single compression stream zcomp_strm_single (mutex-based locking)
-- passing to zcomp_create() num_strm greater than 1 will initialise zcomp
using multi compression stream zcomp_strm_multi (spinlock-based locking)
If ZRAM_MULTI_STREAM has not been selected, only single compression stream
support available.
iozone -t 3 -R -r 16K -s 60M -I +Z
test base 1 strm (mutex) 3 strm (spinlock)
-----------------------------------------------------------------------
Initial write 589286.78 583518.39 718011.05
Rewrite 604837.97 596776.38 1515125.72
Random write 584120.11 595714.58 1388850.25
Pwrite 535731.17 541117.38 739295.27
Fwrite 1418083.88 1478612.72 1484927.06
Usage example:
set max_comp_streams to 4
echo 4 > /sys/block/zram0/max_comp_streams
show current max_comp_streams (default value is 1).
cat /sys/block/zram0/max_comp_streams
Signed-off-by: Sergey Senozhatsky <[email protected]>
---
drivers/block/zram/Kconfig | 10 ++++++++++
drivers/block/zram/zcomp.c | 13 +++++++++++--
drivers/block/zram/zcomp.h | 2 +-
drivers/block/zram/zram_drv.c | 43 ++++++++++++++++++++++++++++++++++++++++++-
drivers/block/zram/zram_drv.h | 2 +-
5 files changed, 65 insertions(+), 5 deletions(-)
diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig
index 3450be8..a2ba9a9 100644
--- a/drivers/block/zram/Kconfig
+++ b/drivers/block/zram/Kconfig
@@ -15,6 +15,16 @@ config ZRAM
See zram.txt for more information.
+config ZRAM_MULTI_STREAM
+ bool "Multi stream compression support"
+ depends on ZRAM
+ default n
+ help
+ This option adds additional functionality to ZRAM, that enables
+ multi compression stream support and provides ability to control
+ maximum number of parallel compressions using max_comp_streams
+ device attribute.
+
config ZRAM_DEBUG
bool "Compressed RAM block device debug support"
depends on ZRAM
diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
index 41325ed..7faa6bd 100644
--- a/drivers/block/zram/zcomp.c
+++ b/drivers/block/zram/zcomp.c
@@ -240,8 +240,9 @@ void zcomp_destroy(struct zcomp *comp)
* if requested algorithm is not supported or in case
* of init error
*/
-struct zcomp *zcomp_create(const char *compress)
+struct zcomp *zcomp_create(const char *compress, int num_strm)
{
+ int ret;
struct zcomp *comp;
struct zcomp_backend *backend;
@@ -254,7 +255,15 @@ struct zcomp *zcomp_create(const char *compress)
return NULL;
comp->backend = backend;
- if (zcomp_strm_single_create(comp) != 0) {
+#ifdef CONFIG_ZRAM_MULTI_STREAM
+ if (num_strm > 1)
+ ret = zcomp_strm_multi_create(comp, num_strm);
+ else
+ ret = zcomp_strm_single_create(comp);
+#else
+ ret = zcomp_strm_single_create(comp);
+#endif
+ if (ret != 0) {
zcomp_destroy(comp);
return NULL;
}
diff --git a/drivers/block/zram/zcomp.h b/drivers/block/zram/zcomp.h
index 8dc1d7f..d7e1229 100644
--- a/drivers/block/zram/zcomp.h
+++ b/drivers/block/zram/zcomp.h
@@ -42,7 +42,7 @@ struct zcomp {
void (*destroy)(struct zcomp *comp);
};
-struct zcomp *zcomp_create(const char *comp);
+struct zcomp *zcomp_create(const char *comp, int num_strm);
void zcomp_destroy(struct zcomp *comp);
struct zcomp_strm *zcomp_strm_get(struct zcomp *comp);
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 200c12a..c147e6f 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -107,6 +107,42 @@ static ssize_t mem_used_total_show(struct device *dev,
return sprintf(buf, "%llu\n", val);
}
+static ssize_t max_comp_streams_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ long val;
+ struct zram *zram = dev_to_zram(dev);
+
+ down_read(&zram->init_lock);
+ val = zram->max_comp_streams;
+ up_read(&zram->init_lock);
+
+ return sprintf(buf, "%ld\n", val);
+}
+
+static ssize_t max_comp_streams_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t len)
+{
+#ifdef CONFIG_ZRAM_MULTI_STREAM
+ long num;
+ struct zram *zram = dev_to_zram(dev);
+
+ if (kstrtol(buf, 0, &num))
+ return -EINVAL;
+ if (num < 1)
+ return -EINVAL;
+ down_write(&zram->init_lock);
+ if (init_done(zram)) {
+ up_write(&zram->init_lock);
+ pr_info("Can't set max_comp_streams for initialized device\n");
+ return -EBUSY;
+ }
+ zram->max_comp_streams = num;
+ up_write(&zram->init_lock);
+#endif
+ return len;
+}
+
/* flag operations needs meta->tb_lock */
static int zram_test_flag(struct zram_meta *meta, u32 index,
enum zram_pageflags flag)
@@ -503,6 +539,7 @@ static void zram_reset_device(struct zram *zram, bool
reset_capacity)
zcomp_destroy(zram->comp);
zram->comp = NULL;
+ zram->max_comp_streams = 1;
zram_meta_free(zram->meta);
zram->meta = NULL;
@@ -532,7 +569,7 @@ static ssize_t disksize_store(struct device *dev,
return -EBUSY;
}
- zram->comp = zcomp_create(default_compressor);
+ zram->comp = zcomp_create(default_compressor, zram->max_comp_streams);
if (!zram->comp) {
up_write(&zram->init_lock);
pr_info("Cannot initialise compressing backend\n");
@@ -695,6 +732,8 @@ static DEVICE_ATTR(initstate, S_IRUGO, initstate_show,
NULL);
static DEVICE_ATTR(reset, S_IWUSR, NULL, reset_store);
static DEVICE_ATTR(orig_data_size, S_IRUGO, orig_data_size_show, NULL);
static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL);
+static DEVICE_ATTR(max_comp_streams, S_IRUGO | S_IWUSR,
+ max_comp_streams_show, max_comp_streams_store);
ZRAM_ATTR_RO(num_reads);
ZRAM_ATTR_RO(num_writes);
@@ -719,6 +758,7 @@ static struct attribute *zram_disk_attrs[] = {
&dev_attr_orig_data_size.attr,
&dev_attr_compr_data_size.attr,
&dev_attr_mem_used_total.attr,
+ &dev_attr_max_comp_streams.attr,
NULL,
};
@@ -782,6 +822,7 @@ static int create_device(struct zram *zram, int device_id)
zram->meta = NULL;
zram->comp = NULL;
+ zram->max_comp_streams = 1;
return 0;
out_free_disk:
diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index 45e04f7..8dccb22 100644
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -99,7 +99,7 @@ struct zram {
* we can store in a disk.
*/
u64 disksize; /* bytes */
-
+ long max_comp_streams;
struct zram_stats stats;
};
#endif
--
1.9.0.291.g027825b
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