[RFC 2/2] ZRAM: add sysfs switch swap_cache_not_keep
From: Hui Zhu <hidden>
Date: 2016-11-25 08:45:39
Also in:
lkml
Subsystem:
block layer, the rest, zram compressed ram block device drvier · Maintainers:
Jens Axboe, Linus Torvalds, Minchan Kim, Sergey Senozhatsky
This patch add a sysfs interface swap_cache_not_keep to control the swap cache rule for a ZRAM disk. Swap will not keep the swap cache anytime if it set to 1. Signed-off-by: Hui Zhu <redacted> --- drivers/block/zram/zram_drv.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 04365b1..bda9bbf 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c@@ -30,6 +30,8 @@ #include <linux/err.h> #include <linux/idr.h> #include <linux/sysfs.h> +#include <linux/swap.h> +#include <asm/barrier.h> #include "zram_drv.h"
@@ -1158,6 +1160,32 @@ static ssize_t reset_store(struct device *dev, return len; } +#ifdef CONFIG_SWAP_CACHE_RULE +static ssize_t swap_cache_not_keep_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return scnprintf(buf, PAGE_SIZE, "%d\n", + zram->disk->swap_cache_not_keep); +} + +static ssize_t swap_cache_not_keep_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t len) +{ + struct zram *zram = dev_to_zram(dev); + bool rule; + + if (strtobool(buf, &rule) < 0) + return -EINVAL; + WRITE_ONCE(zram->disk->swap_cache_not_keep, rule); + + swap_cache_rule_update(); + + return len; +} +#endif + static int zram_open(struct block_device *bdev, fmode_t mode) { int ret = 0;
@@ -1190,6 +1218,9 @@ static int zram_open(struct block_device *bdev, fmode_t mode) static DEVICE_ATTR_RW(mem_used_max); static DEVICE_ATTR_RW(max_comp_streams); static DEVICE_ATTR_RW(comp_algorithm); +#ifdef CONFIG_SWAP_CACHE_RULE +static DEVICE_ATTR_RW(swap_cache_not_keep); +#endif static struct attribute *zram_disk_attrs[] = { &dev_attr_disksize.attr,
@@ -1213,6 +1244,9 @@ static int zram_open(struct block_device *bdev, fmode_t mode) &dev_attr_io_stat.attr, &dev_attr_mm_stat.attr, &dev_attr_debug_stat.attr, +#ifdef CONFIG_SWAP_CACHE_RULE + &dev_attr_swap_cache_not_keep.attr, +#endif NULL, };
--
1.9.1
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