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authorMinchan Kim <minchan@kernel.org>2018-12-28 00:36:44 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-12-28 12:11:49 -0800
commite82592c4fd7eafe8dec12a70436e93e3afb28556 (patch)
tree89d470bbfcb0f97e7f3ed3f1516d038403992078 /drivers/block/zram
parent7e5292831b346bacb05558ca385cae366187314c (diff)
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zram: introduce ZRAM_IDLE flag
To support idle page writeback with upcoming patches, this patch introduces a new ZRAM_IDLE flag. Userspace can mark zram slots as "idle" via "echo all > /sys/block/zramX/idle" which marks every allocated zram slot as ZRAM_IDLE. User could see it by /sys/kernel/debug/zram/zram0/block_state. 300 75.033841 ...i 301 63.806904 s..i 302 63.806919 ..hi Once there is IO for the slot, the mark will be disappeared. 300 75.033841 ... 301 63.806904 s..i 302 63.806919 ..hi Therefore, 300th block is idle zpage. With this feature, user can how many zram has idle pages which are waste of memory. Link: http://lkml.kernel.org/r/20181127055429.251614-5-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Joey Pabalinas <joeypabalinas@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/block/zram')
-rw-r--r--drivers/block/zram/zram_drv.c57
-rw-r--r--drivers/block/zram/zram_drv.h1
2 files changed, 55 insertions, 3 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 4457d0395bfb..180613b478a6 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -281,6 +281,47 @@ static ssize_t mem_used_max_store(struct device *dev,
return len;
}
+static ssize_t idle_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t len)
+{
+ struct zram *zram = dev_to_zram(dev);
+ unsigned long nr_pages = zram->disksize >> PAGE_SHIFT;
+ int index;
+ char mode_buf[8];
+ ssize_t sz;
+
+ sz = strscpy(mode_buf, buf, sizeof(mode_buf));
+ if (sz <= 0)
+ return -EINVAL;
+
+ /* ignore trailing new line */
+ if (mode_buf[sz - 1] == '\n')
+ mode_buf[sz - 1] = 0x00;
+
+ if (strcmp(mode_buf, "all"))
+ return -EINVAL;
+
+ down_read(&zram->init_lock);
+ if (!init_done(zram)) {
+ up_read(&zram->init_lock);
+ return -EINVAL;
+ }
+
+ for (index = 0; index < nr_pages; index++) {
+ zram_slot_lock(zram, index);
+ if (!zram_allocated(zram, index))
+ goto next;
+
+ zram_set_flag(zram, index, ZRAM_IDLE);
+next:
+ zram_slot_unlock(zram, index);
+ }
+
+ up_read(&zram->init_lock);
+
+ return len;
+}
+
#ifdef CONFIG_ZRAM_WRITEBACK
static void reset_bdev(struct zram *zram)
{
@@ -638,6 +679,7 @@ static void zram_debugfs_destroy(void)
static void zram_accessed(struct zram *zram, u32 index)
{
+ zram_clear_flag(zram, index, ZRAM_IDLE);
zram->table[index].ac_time = ktime_get_boottime();
}
@@ -670,12 +712,13 @@ static ssize_t read_block_state(struct file *file, char __user *buf,
ts = ktime_to_timespec64(zram->table[index].ac_time);
copied = snprintf(kbuf + written, count,
- "%12zd %12lld.%06lu %c%c%c\n",
+ "%12zd %12lld.%06lu %c%c%c%c\n",
index, (s64)ts.tv_sec,
ts.tv_nsec / NSEC_PER_USEC,
zram_test_flag(zram, index, ZRAM_SAME) ? 's' : '.',
zram_test_flag(zram, index, ZRAM_WB) ? 'w' : '.',
- zram_test_flag(zram, index, ZRAM_HUGE) ? 'h' : '.');
+ zram_test_flag(zram, index, ZRAM_HUGE) ? 'h' : '.',
+ zram_test_flag(zram, index, ZRAM_IDLE) ? 'i' : '.');
if (count < copied) {
zram_slot_unlock(zram, index);
@@ -720,7 +763,10 @@ static void zram_debugfs_unregister(struct zram *zram)
#else
static void zram_debugfs_create(void) {};
static void zram_debugfs_destroy(void) {};
-static void zram_accessed(struct zram *zram, u32 index) {};
+static void zram_accessed(struct zram *zram, u32 index)
+{
+ zram_clear_flag(zram, index, ZRAM_IDLE);
+};
static void zram_debugfs_register(struct zram *zram) {};
static void zram_debugfs_unregister(struct zram *zram) {};
#endif
@@ -924,6 +970,9 @@ static void zram_free_page(struct zram *zram, size_t index)
#ifdef CONFIG_ZRAM_MEMORY_TRACKING
zram->table[index].ac_time = 0;
#endif
+ if (zram_test_flag(zram, index, ZRAM_IDLE))
+ zram_clear_flag(zram, index, ZRAM_IDLE);
+
if (zram_test_flag(zram, index, ZRAM_HUGE)) {
zram_clear_flag(zram, index, ZRAM_HUGE);
atomic64_dec(&zram->stats.huge_pages);
@@ -1589,6 +1638,7 @@ static DEVICE_ATTR_RO(initstate);
static DEVICE_ATTR_WO(reset);
static DEVICE_ATTR_WO(mem_limit);
static DEVICE_ATTR_WO(mem_used_max);
+static DEVICE_ATTR_WO(idle);
static DEVICE_ATTR_RW(max_comp_streams);
static DEVICE_ATTR_RW(comp_algorithm);
#ifdef CONFIG_ZRAM_WRITEBACK
@@ -1602,6 +1652,7 @@ static struct attribute *zram_disk_attrs[] = {
&dev_attr_compact.attr,
&dev_attr_mem_limit.attr,
&dev_attr_mem_used_max.attr,
+ &dev_attr_idle.attr,
&dev_attr_max_comp_streams.attr,
&dev_attr_comp_algorithm.attr,
#ifdef CONFIG_ZRAM_WRITEBACK
diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index 4f83f1f14b0a..a84611b97867 100644
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -48,6 +48,7 @@ enum zram_pageflags {
ZRAM_SAME, /* Page consists the same element */
ZRAM_WB, /* page is stored on backing_device */
ZRAM_HUGE, /* Incompressible page */
+ ZRAM_IDLE, /* not accessed page since last idle marking */
__NR_ZRAM_PAGEFLAGS,
};