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authorSergey Senozhatsky <senozhatsky@chromium.org>2022-11-09 14:50:36 +0300
committerAndrew Morton <akpm@linux-foundation.org>2022-12-01 02:58:51 +0300
commit001d9273570115b2eb360d5452bbc46f6cc063a1 (patch)
tree50e7c738ab37bf93cb40ab995c8aabaac834b8ef /drivers
parent7ac07a26dea79c3892436bce41cce03dcbd3c4c7 (diff)
downloadlinux-001d9273570115b2eb360d5452bbc46f6cc063a1.tar.xz
zram: add recompression algorithm sysfs knob
Introduce recomp_algorithm sysfs knob that controls secondary algorithm selection used for recompression. We will support up to 3 secondary compression algorithms which are sorted in order of their priority. To select an algorithm user has to provide its name and priority: echo "algo=zstd priority=1" > /sys/block/zramX/recomp_algorithm echo "algo=deflate priority=2" > /sys/block/zramX/recomp_algorithm During recompression zram iterates through the list of registered secondary algorithms in order of their priorities. We also have a short version for cases when there is only one secondary compression algorithm: echo "algo=zstd" > /sys/block/zramX/recomp_algorithm This will register zstd as the secondary algorithm with priority 1. Link: https://lkml.kernel.org/r/20221109115047.2921851-3-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Alexey Romanov <avromanov@sberdevices.ru> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Suleiman Souhlal <suleiman@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/block/zram/zram_drv.c124
1 files changed, 105 insertions, 19 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index fbe46c6177fd..8ea4908f5961 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -997,31 +997,28 @@ static ssize_t max_comp_streams_store(struct device *dev,
return len;
}
-static ssize_t comp_algorithm_show(struct device *dev,
- struct device_attribute *attr, char *buf)
+static void comp_algorithm_set(struct zram *zram, u32 prio, const char *alg)
{
- size_t sz;
- struct zram *zram = dev_to_zram(dev);
+ /* Do not free statically defined compression algorithms */
+ if (zram->comp_algs[prio] != default_compressor)
+ kfree(zram->comp_algs[prio]);
+
+ zram->comp_algs[prio] = alg;
+}
+
+static ssize_t __comp_algorithm_show(struct zram *zram, u32 prio, char *buf)
+{
+ ssize_t sz;
down_read(&zram->init_lock);
- sz = zcomp_available_show(zram->comp_algs[ZRAM_PRIMARY_COMP], buf);
+ sz = zcomp_available_show(zram->comp_algs[prio], buf);
up_read(&zram->init_lock);
return sz;
}
-static void comp_algorithm_set(struct zram *zram, u32 prio, const char *alg)
+static int __comp_algorithm_store(struct zram *zram, u32 prio, const char *buf)
{
- /* Do not kfree() algs that we didn't allocate, IOW the default ones */
- if (zram->comp_algs[prio] != default_compressor)
- kfree(zram->comp_algs[prio]);
- zram->comp_algs[prio] = alg;
-}
-
-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);
char *compressor;
size_t sz;
@@ -1050,11 +1047,94 @@ static ssize_t comp_algorithm_store(struct device *dev,
return -EBUSY;
}
- comp_algorithm_set(zram, ZRAM_PRIMARY_COMP, compressor);
+ comp_algorithm_set(zram, prio, compressor);
up_write(&zram->init_lock);
- return len;
+ return 0;
+}
+
+static ssize_t comp_algorithm_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct zram *zram = dev_to_zram(dev);
+
+ return __comp_algorithm_show(zram, ZRAM_PRIMARY_COMP, buf);
+}
+
+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);
+ int ret;
+
+ ret = __comp_algorithm_store(zram, ZRAM_PRIMARY_COMP, buf);
+ return ret ? ret : len;
}
+#ifdef CONFIG_ZRAM_MULTI_COMP
+static ssize_t recomp_algorithm_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct zram *zram = dev_to_zram(dev);
+ ssize_t sz = 0;
+ u32 prio;
+
+ for (prio = ZRAM_SECONDARY_COMP; prio < ZRAM_MAX_COMPS; prio++) {
+ if (!zram->comp_algs[prio])
+ continue;
+
+ sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2, "#%d: ", prio);
+ sz += __comp_algorithm_show(zram, prio, buf + sz);
+ }
+
+ return sz;
+}
+
+static ssize_t recomp_algorithm_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ struct zram *zram = dev_to_zram(dev);
+ int prio = ZRAM_SECONDARY_COMP;
+ char *args, *param, *val;
+ char *alg = NULL;
+ int ret;
+
+ args = skip_spaces(buf);
+ while (*args) {
+ args = next_arg(args, &param, &val);
+
+ if (!*val)
+ return -EINVAL;
+
+ if (!strcmp(param, "algo")) {
+ alg = val;
+ continue;
+ }
+
+ if (!strcmp(param, "priority")) {
+ ret = kstrtoint(val, 10, &prio);
+ if (ret)
+ return ret;
+ continue;
+ }
+ }
+
+ if (!alg)
+ return -EINVAL;
+
+ if (prio < ZRAM_SECONDARY_COMP || prio >= ZRAM_MAX_COMPS)
+ return -EINVAL;
+
+ ret = __comp_algorithm_store(zram, prio, alg);
+ return ret ? ret : len;
+}
+#endif
+
static ssize_t compact_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t len)
{
@@ -1895,6 +1975,9 @@ static DEVICE_ATTR_WO(writeback);
static DEVICE_ATTR_RW(writeback_limit);
static DEVICE_ATTR_RW(writeback_limit_enable);
#endif
+#ifdef CONFIG_ZRAM_MULTI_COMP
+static DEVICE_ATTR_RW(recomp_algorithm);
+#endif
static struct attribute *zram_disk_attrs[] = {
&dev_attr_disksize.attr,
@@ -1918,6 +2001,9 @@ static struct attribute *zram_disk_attrs[] = {
&dev_attr_bd_stat.attr,
#endif
&dev_attr_debug_stat.attr,
+#ifdef CONFIG_ZRAM_MULTI_COMP
+ &dev_attr_recomp_algorithm.attr,
+#endif
NULL,
};
@@ -1997,7 +2083,7 @@ static int zram_add(void)
if (ret)
goto out_cleanup_disk;
- zram->comp_algs[ZRAM_PRIMARY_COMP] = default_compressor;
+ comp_algorithm_set(zram, ZRAM_PRIMARY_COMP, default_compressor);
zram_debugfs_register(zram);
pr_info("Added device: %s\n", zram->disk->disk_name);