Subject: [merged] zram-make-compression-algorithm-selection-possible.patch removed from -mm tree
To: sergey.senozhatsky@xxxxxxxxx,jmarchan@xxxxxxxxxx,minchan@xxxxxxxxxx,ngupta@xxxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Tue, 08 Apr 2014 14:08:45 -0700
The patch titled
Subject: zram: make compression algorithm selection possible
has been removed from the -mm tree. Its filename was
zram-make-compression-algorithm-selection-possible.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
Subject: zram: make compression algorithm selection possible
Add and document `comp_algorithm' device attribute. This attribute allows
to show supported compression and currently selected compression
algorithms:
cat /sys/block/zram0/comp_algorithm
[lzo] lz4
and change selected compression algorithm:
echo lzo > /sys/block/zram0/comp_algorithm
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
Acked-by: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Jerome Marchand <jmarchan@xxxxxxxxxx>
Cc: Nitin Gupta <ngupta@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/ABI/testing/sysfs-block-zram | 8 ++++
Documentation/blockdev/zram.txt | 24 +++++++++---
drivers/block/zram/zcomp.c | 32 ++++++++++++++--
drivers/block/zram/zcomp.h | 2 +
drivers/block/zram/zram_drv.c | 37 +++++++++++++++++--
drivers/block/zram/zram_drv.h | 1
6 files changed, 93 insertions(+), 11 deletions(-)
diff -puN Documentation/ABI/testing/sysfs-block-zram~zram-make-compression-algorithm-selection-possible Documentation/ABI/testing/sysfs-block-zram
--- a/Documentation/ABI/testing/sysfs-block-zram~zram-make-compression-algorithm-selection-possible
+++ a/Documentation/ABI/testing/sysfs-block-zram
@@ -65,6 +65,14 @@ Description:
number of backend's zcomp_strm compression streams (number of
concurrent compress operations).
+What: /sys/block/zram<id>/comp_algorithm
+Date: February 2014
+Contact: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
+Description:
+ The comp_algorithm file is read-write and lets to show
+ available and selected compression algorithms, change
+ compression algorithm selection.
+
What: /sys/block/zram<id>/notify_free
Date: August 2010
Contact: Nitin Gupta <ngupta@xxxxxxxxxx>
diff -puN Documentation/blockdev/zram.txt~zram-make-compression-algorithm-selection-possible Documentation/blockdev/zram.txt
--- a/Documentation/blockdev/zram.txt~zram-make-compression-algorithm-selection-possible
+++ a/Documentation/blockdev/zram.txt
@@ -42,7 +42,21 @@ will not take any effect, because single
as a special case and does not support dynamic max_comp_streams. Only multi
stream backend supports dynamic max_comp_streams adjustment.
-3) Set Disksize
+3) Select compression algorithm
+ Using comp_algorithm device attribute one can see available and
+ currently selected (shown in square brackets) compression algortithms,
+ change selected compression algorithm (once the device is initialised
+ there is no way to change compression algorithm).
+
+ Examples:
+ #show supported compression algorithms
+ cat /sys/block/zram0/comp_algorithm
+ lzo [lz4]
+
+ #select lzo compression algorithm
+ echo lzo > /sys/block/zram0/comp_algorithm
+
+4) Set Disksize
Set disk size by writing the value to sysfs node 'disksize'.
The value can be either in bytes or you can use mem suffixes.
Examples:
@@ -59,14 +73,14 @@ There is little point creating a zram of
since we expect a 2:1 compression ratio. Note that zram uses about 0.1% of the
size of the disk when not in use so a huge zram is wasteful.
-4) Activate:
+5) Activate:
mkswap /dev/zram0
swapon /dev/zram0
mkfs.ext4 /dev/zram1
mount /dev/zram1 /tmp
-5) Stats:
+6) Stats:
Per-device statistics are exported as various nodes under
/sys/block/zram<id>/
disksize
@@ -81,11 +95,11 @@ size of the disk when not in use so a hu
compr_data_size
mem_used_total
-6) Deactivate:
+7) Deactivate:
swapoff /dev/zram0
umount /dev/zram1
-7) Reset:
+8) Reset:
Write any positive value to 'reset' sysfs node
echo 1 > /sys/block/zram0/reset
echo 1 > /sys/block/zram1/reset
diff -puN drivers/block/zram/zcomp.c~zram-make-compression-algorithm-selection-possible drivers/block/zram/zcomp.c
--- a/drivers/block/zram/zcomp.c~zram-make-compression-algorithm-selection-possible
+++ a/drivers/block/zram/zcomp.c
@@ -39,11 +39,20 @@ struct zcomp_strm_multi {
wait_queue_head_t strm_wait;
};
+static struct zcomp_backend *backends[] = {
+ &zcomp_lzo,
+ NULL
+};
+
static struct zcomp_backend *find_backend(const char *compress)
{
- if (strncmp(compress, "lzo", 3) == 0)
- return &zcomp_lzo;
- return NULL;
+ int i = 0;
+ while (backends[i]) {
+ if (sysfs_streq(compress, backends[i]->name))
+ break;
+ i++;
+ }
+ return backends[i];
}
static void zcomp_strm_free(struct zcomp *comp, struct zcomp_strm *zstrm)
@@ -251,6 +260,23 @@ static int zcomp_strm_single_create(stru
return 0;
}
+/* show available compressors */
+ssize_t zcomp_available_show(const char *comp, char *buf)
+{
+ ssize_t sz = 0;
+ int i = 0;
+
+ while (backends[i]) {
+ if (sysfs_streq(comp, backends[i]->name))
+ sz += sprintf(buf + sz, "[%s] ", backends[i]->name);
+ else
+ sz += sprintf(buf + sz, "%s ", backends[i]->name);
+ i++;
+ }
+ sz += sprintf(buf + sz, "\n");
+ return sz;
+}
+
int zcomp_set_max_streams(struct zcomp *comp, int num_strm)
{
return comp->set_max_streams(comp, num_strm);
diff -puN drivers/block/zram/zcomp.h~zram-make-compression-algorithm-selection-possible drivers/block/zram/zcomp.h
--- a/drivers/block/zram/zcomp.h~zram-make-compression-algorithm-selection-possible
+++ a/drivers/block/zram/zcomp.h
@@ -50,6 +50,8 @@ struct zcomp {
void (*destroy)(struct zcomp *comp);
};
+ssize_t zcomp_available_show(const char *comp, char *buf);
+
struct zcomp *zcomp_create(const char *comp, int max_strm);
void zcomp_destroy(struct zcomp *comp);
diff -puN drivers/block/zram/zram_drv.c~zram-make-compression-algorithm-selection-possible drivers/block/zram/zram_drv.c
--- a/drivers/block/zram/zram_drv.c~zram-make-compression-algorithm-selection-possible
+++ a/drivers/block/zram/zram_drv.c
@@ -141,6 +141,34 @@ static ssize_t max_comp_streams_store(st
return len;
}
+static ssize_t comp_algorithm_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ size_t sz;
+ struct zram *zram = dev_to_zram(dev);
+
+ down_read(&zram->init_lock);
+ sz = zcomp_available_show(zram->compressor, buf);
+ up_read(&zram->init_lock);
+
+ return sz;
+}
+
+static ssize_t comp_algorithm_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t len)
+{
+ struct zram *zram = dev_to_zram(dev);
+ down_write(&zram->init_lock);
+ if (init_done(zram)) {
+ up_write(&zram->init_lock);
+ pr_info("Can't change algorithm for initialized device\n");
+ return -EBUSY;
+ }
+ strlcpy(zram->compressor, buf, sizeof(zram->compressor));
+ up_write(&zram->init_lock);
+ return len;
+}
+
/* flag operations needs meta->tb_lock */
static int zram_test_flag(struct zram_meta *meta, u32 index,
enum zram_pageflags flag)
@@ -572,10 +600,10 @@ static ssize_t disksize_store(struct dev
goto out_free_meta;
}
- zram->comp = zcomp_create(default_compressor, zram->max_comp_streams);
+ zram->comp = zcomp_create(zram->compressor, zram->max_comp_streams);
if (!zram->comp) {
pr_info("Cannot initialise %s compressing backend\n",
- default_compressor);
+ zram->compressor);
err = -EINVAL;
goto out_free_meta;
}
@@ -735,6 +763,8 @@ static DEVICE_ATTR(orig_data_size, S_IRU
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);
+static DEVICE_ATTR(comp_algorithm, S_IRUGO | S_IWUSR,
+ comp_algorithm_show, comp_algorithm_store);
ZRAM_ATTR_RO(num_reads);
ZRAM_ATTR_RO(num_writes);
@@ -760,6 +790,7 @@ static struct attribute *zram_disk_attrs
&dev_attr_compr_data_size.attr,
&dev_attr_mem_used_total.attr,
&dev_attr_max_comp_streams.attr,
+ &dev_attr_comp_algorithm.attr,
NULL,
};
@@ -820,7 +851,7 @@ static int create_device(struct zram *zr
pr_warn("Error creating sysfs group");
goto out_free_disk;
}
-
+ strlcpy(zram->compressor, default_compressor, sizeof(zram->compressor));
zram->meta = NULL;
zram->max_comp_streams = 1;
return 0;
diff -puN drivers/block/zram/zram_drv.h~zram-make-compression-algorithm-selection-possible drivers/block/zram/zram_drv.h
--- a/drivers/block/zram/zram_drv.h~zram-make-compression-algorithm-selection-possible
+++ a/drivers/block/zram/zram_drv.h
@@ -101,5 +101,6 @@ struct zram {
u64 disksize; /* bytes */
int max_comp_streams;
struct zram_stats stats;
+ char compressor[10];
};
#endif
_
Patches currently in -mm which might be from sergey.senozhatsky@xxxxxxxxx are
origin.patch
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