diff options
| author | Richard Chang <richardycc@google.com> | 2025-12-01 18:47:49 +0900 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-01-20 19:24:36 -0800 |
| commit | 4c1d61389e8e4307449eb2ebad997241cbf08fef (patch) | |
| tree | 1bd60c269c042a2a9c6a2eca6a8c1268b65e101d /drivers | |
| parent | d38fab605c66778a8ddfbe2ac66c3a3eb7b2295a (diff) | |
zram: introduce writeback_compressed device attribute
Introduce witeback_compressed device attribute to toggle compressed
writeback (decompression on demand) feature.
[senozhatsky@chromium.org: rewrote original patch, added documentation]
Link: https://lkml.kernel.org/r/20251201094754.4149975-3-senozhatsky@chromium.org
Signed-off-by: Richard Chang <richardycc@google.com>
Co-developed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: David Stevens <stevensd@google.com>
Cc: Minchan Kim <minchan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/block/zram/zram_drv.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 6263d300312e..3cc03c3f7389 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -539,6 +539,42 @@ struct zram_rb_req { u32 index; }; +static ssize_t writeback_compressed_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct zram *zram = dev_to_zram(dev); + bool val; + + if (kstrtobool(buf, &val)) + return -EINVAL; + + down_write(&zram->init_lock); + if (init_done(zram)) { + up_write(&zram->init_lock); + return -EBUSY; + } + + zram->wb_compressed = val; + up_write(&zram->init_lock); + + return len; +} + +static ssize_t writeback_compressed_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + bool val; + struct zram *zram = dev_to_zram(dev); + + down_read(&zram->init_lock); + val = zram->wb_compressed; + up_read(&zram->init_lock); + + return sysfs_emit(buf, "%d\n", val); +} + static ssize_t writeback_limit_enable_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) @@ -3048,6 +3084,7 @@ static DEVICE_ATTR_WO(writeback); static DEVICE_ATTR_RW(writeback_limit); static DEVICE_ATTR_RW(writeback_limit_enable); static DEVICE_ATTR_RW(writeback_batch_size); +static DEVICE_ATTR_RW(writeback_compressed); #endif #ifdef CONFIG_ZRAM_MULTI_COMP static DEVICE_ATTR_RW(recomp_algorithm); @@ -3070,6 +3107,7 @@ static struct attribute *zram_disk_attrs[] = { &dev_attr_writeback_limit.attr, &dev_attr_writeback_limit_enable.attr, &dev_attr_writeback_batch_size.attr, + &dev_attr_writeback_compressed.attr, #endif &dev_attr_io_stat.attr, &dev_attr_mm_stat.attr, |