aboutsummaryrefslogtreecommitdiff
path: root/drivers/block
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/zram/Kconfig14
-rw-r--r--drivers/block/zram/zram_drv.c165
-rw-r--r--drivers/block/zram/zram_drv.h14
3 files changed, 174 insertions, 19 deletions
diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig
index ac3a31d433b2..635235759a0a 100644
--- a/drivers/block/zram/Kconfig
+++ b/drivers/block/zram/Kconfig
@@ -13,7 +13,7 @@ config ZRAM
It has several use cases, for example: /tmp storage, use as swap
disks and maybe many more.
- See zram.txt for more information.
+ See Documentation/blockdev/zram.txt for more information.
config ZRAM_WRITEBACK
bool "Write back incompressible page to backing device"
@@ -25,4 +25,14 @@ config ZRAM_WRITEBACK
For this feature, admin should set up backing device via
/sys/block/zramX/backing_dev.
- See zram.txt for more infomration.
+ See Documentation/blockdev/zram.txt for more information.
+
+config ZRAM_MEMORY_TRACKING
+ bool "Track zRam block status"
+ depends on ZRAM && DEBUG_FS
+ help
+ With this feature, admin can track the state of allocated blocks
+ of zRAM. Admin could see the information via
+ /sys/kernel/debug/zram/zramX/block_state.
+
+ See Documentation/blockdev/zram.txt for more information.
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 0f3fadd71230..da51293e7c03 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -31,6 +31,7 @@
#include <linux/err.h>
#include <linux/idr.h>
#include <linux/sysfs.h>
+#include <linux/debugfs.h>
#include <linux/cpuhotplug.h>
#include "zram_drv.h"
@@ -52,11 +53,28 @@ static size_t huge_class_size;
static void zram_free_page(struct zram *zram, size_t index);
+static void zram_slot_lock(struct zram *zram, u32 index)
+{
+ bit_spin_lock(ZRAM_LOCK, &zram->table[index].value);
+}
+
+static void zram_slot_unlock(struct zram *zram, u32 index)
+{
+ bit_spin_unlock(ZRAM_LOCK, &zram->table[index].value);
+}
+
static inline bool init_done(struct zram *zram)
{
return zram->disksize;
}
+static inline bool zram_allocated(struct zram *zram, u32 index)
+{
+
+ return (zram->table[index].value >> (ZRAM_FLAG_SHIFT + 1)) ||
+ zram->table[index].handle;
+}
+
static inline struct zram *dev_to_zram(struct device *dev)
{
return (struct zram *)dev_to_disk(dev)->private_data;
@@ -73,7 +91,7 @@ static void zram_set_handle(struct zram *zram, u32 index, unsigned long handle)
}
/* flag operations require table entry bit_spin_lock() being held */
-static int zram_test_flag(struct zram *zram, u32 index,
+static bool zram_test_flag(struct zram *zram, u32 index,
enum zram_pageflags flag)
{
return zram->table[index].value & BIT(flag);
@@ -600,6 +618,114 @@ static int read_from_bdev(struct zram *zram, struct bio_vec *bvec,
static void zram_wb_clear(struct zram *zram, u32 index) {}
#endif
+#ifdef CONFIG_ZRAM_MEMORY_TRACKING
+
+static struct dentry *zram_debugfs_root;
+
+static void zram_debugfs_create(void)
+{
+ zram_debugfs_root = debugfs_create_dir("zram", NULL);
+}
+
+static void zram_debugfs_destroy(void)
+{
+ debugfs_remove_recursive(zram_debugfs_root);
+}
+
+static void zram_accessed(struct zram *zram, u32 index)
+{
+ zram->table[index].ac_time = ktime_get_boottime();
+}
+
+static void zram_reset_access(struct zram *zram, u32 index)
+{
+ zram->table[index].ac_time = 0;
+}
+
+static ssize_t read_block_state(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ char *kbuf;
+ ssize_t index, written = 0;
+ struct zram *zram = file->private_data;
+ unsigned long nr_pages = zram->disksize >> PAGE_SHIFT;
+ struct timespec64 ts;
+
+ kbuf = kvmalloc(count, GFP_KERNEL);
+ if (!kbuf)
+ return -ENOMEM;
+
+ down_read(&zram->init_lock);
+ if (!init_done(zram)) {
+ up_read(&zram->init_lock);
+ kvfree(kbuf);
+ return -EINVAL;
+ }
+
+ for (index = *ppos; index < nr_pages; index++) {
+ int copied;
+
+ zram_slot_lock(zram, index);
+ if (!zram_allocated(zram, index))
+ goto next;
+
+ ts = ktime_to_timespec64(zram->table[index].ac_time);
+ copied = snprintf(kbuf + written, count,
+ "%12zd %12lld.%06lu %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' : '.');
+
+ if (count < copied) {
+ zram_slot_unlock(zram, index);
+ break;
+ }
+ written += copied;
+ count -= copied;
+next:
+ zram_slot_unlock(zram, index);
+ *ppos += 1;
+ }
+
+ up_read(&zram->init_lock);
+ if (copy_to_user(buf, kbuf, written))
+ written = -EFAULT;
+ kvfree(kbuf);
+
+ return written;
+}
+
+static const struct file_operations proc_zram_block_state_op = {
+ .open = simple_open,
+ .read = read_block_state,
+ .llseek = default_llseek,
+};
+
+static void zram_debugfs_register(struct zram *zram)
+{
+ if (!zram_debugfs_root)
+ return;
+
+ zram->debugfs_dir = debugfs_create_dir(zram->disk->disk_name,
+ zram_debugfs_root);
+ debugfs_create_file("block_state", 0400, zram->debugfs_dir,
+ zram, &proc_zram_block_state_op);
+}
+
+static void zram_debugfs_unregister(struct zram *zram)
+{
+ debugfs_remove_recursive(zram->debugfs_dir);
+}
+#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_reset_access(struct zram *zram, u32 index) {};
+static void zram_debugfs_register(struct zram *zram) {};
+static void zram_debugfs_unregister(struct zram *zram) {};
+#endif
/*
* We switched to per-cpu streams and this attr is not needed anymore.
@@ -719,14 +845,15 @@ static ssize_t mm_stat_show(struct device *dev,
max_used = atomic_long_read(&zram->stats.max_used_pages);
ret = scnprintf(buf, PAGE_SIZE,
- "%8llu %8llu %8llu %8lu %8ld %8llu %8lu\n",
+ "%8llu %8llu %8llu %8lu %8ld %8llu %8lu %8llu\n",
orig_size << PAGE_SHIFT,
(u64)atomic64_read(&zram->stats.compr_data_size),
mem_used << PAGE_SHIFT,
zram->limit_pages << PAGE_SHIFT,
max_used << PAGE_SHIFT,
(u64)atomic64_read(&zram->stats.same_pages),
- pool_stats.pages_compacted);
+ pool_stats.pages_compacted,
+ (u64)atomic64_read(&zram->stats.huge_pages));
up_read(&zram->init_lock);
return ret;
@@ -753,16 +880,6 @@ static DEVICE_ATTR_RO(io_stat);
static DEVICE_ATTR_RO(mm_stat);
static DEVICE_ATTR_RO(debug_stat);
-static void zram_slot_lock(struct zram *zram, u32 index)
-{
- bit_spin_lock(ZRAM_ACCESS, &zram->table[index].value);
-}
-
-static void zram_slot_unlock(struct zram *zram, u32 index)
-{
- bit_spin_unlock(ZRAM_ACCESS, &zram->table[index].value);
-}
-
static void zram_meta_free(struct zram *zram, u64 disksize)
{
size_t num_pages = disksize >> PAGE_SHIFT;
@@ -805,6 +922,13 @@ static void zram_free_page(struct zram *zram, size_t index)
{
unsigned long handle;
+ zram_reset_access(zram, index);
+
+ if (zram_test_flag(zram, index, ZRAM_HUGE)) {
+ zram_clear_flag(zram, index, ZRAM_HUGE);
+ atomic64_dec(&zram->stats.huge_pages);
+ }
+
if (zram_wb_enabled(zram) && zram_test_flag(zram, index, ZRAM_WB)) {
zram_wb_clear(zram, index);
atomic64_dec(&zram->stats.pages_stored);
@@ -973,6 +1097,7 @@ compress_again:
}
if (unlikely(comp_len >= huge_class_size)) {
+ comp_len = PAGE_SIZE;
if (zram_wb_enabled(zram) && allow_wb) {
zcomp_stream_put(zram->comp);
ret = write_to_bdev(zram, bvec, index, bio, &element);
@@ -984,7 +1109,6 @@ compress_again:
allow_wb = false;
goto compress_again;
}
- comp_len = PAGE_SIZE;
}
/*
@@ -1046,6 +1170,11 @@ out:
zram_slot_lock(zram, index);
zram_free_page(zram, index);
+ if (comp_len == PAGE_SIZE) {
+ zram_set_flag(zram, index, ZRAM_HUGE);
+ atomic64_inc(&zram->stats.huge_pages);
+ }
+
if (flags) {
zram_set_flag(zram, index, flags);
zram_set_element(zram, index, element);
@@ -1166,6 +1295,10 @@ static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index,
generic_end_io_acct(q, rw_acct, &zram->disk->part0, start_time);
+ zram_slot_lock(zram, index);
+ zram_accessed(zram, index);
+ zram_slot_unlock(zram, index);
+
if (unlikely(ret < 0)) {
if (!is_write)
atomic64_inc(&zram->stats.failed_reads);
@@ -1577,6 +1710,7 @@ static int zram_add(void)
}
strlcpy(zram->compressor, default_compressor, sizeof(zram->compressor));
+ zram_debugfs_register(zram);
pr_info("Added device: %s\n", zram->disk->disk_name);
return device_id;
@@ -1610,6 +1744,7 @@ static int zram_remove(struct zram *zram)
zram->claim = true;
mutex_unlock(&bdev->bd_mutex);
+ zram_debugfs_unregister(zram);
/*
* Remove sysfs first, so no one will perform a disksize
* store while we destroy the devices. This also helps during
@@ -1712,6 +1847,7 @@ static void destroy_devices(void)
{
class_unregister(&zram_control_class);
idr_for_each(&zram_index_idr, &zram_remove_cb, NULL);
+ zram_debugfs_destroy();
idr_destroy(&zram_index_idr);
unregister_blkdev(zram_major, "zram");
cpuhp_remove_multi_state(CPUHP_ZCOMP_PREPARE);
@@ -1733,6 +1869,7 @@ static int __init zram_init(void)
return ret;
}
+ zram_debugfs_create();
zram_major = register_blkdev(0, "zram");
if (zram_major <= 0) {
pr_err("Unable to get major number\n");
diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index 008861220723..72c8584b6dff 100644
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -43,10 +43,11 @@
/* Flags for zram pages (table[page_no].value) */
enum zram_pageflags {
- /* Page consists the same element */
- ZRAM_SAME = ZRAM_FLAG_SHIFT,
- ZRAM_ACCESS, /* page is now accessed */
+ /* zram slot is locked */
+ ZRAM_LOCK = ZRAM_FLAG_SHIFT,
+ ZRAM_SAME, /* Page consists the same element */
ZRAM_WB, /* page is stored on backing_device */
+ ZRAM_HUGE, /* Incompressible page */
__NR_ZRAM_PAGEFLAGS,
};
@@ -60,6 +61,9 @@ struct zram_table_entry {
unsigned long element;
};
unsigned long value;
+#ifdef CONFIG_ZRAM_MEMORY_TRACKING
+ ktime_t ac_time;
+#endif
};
struct zram_stats {
@@ -71,6 +75,7 @@ struct zram_stats {
atomic64_t invalid_io; /* non-page-aligned I/O requests */
atomic64_t notify_free; /* no. of swap slot free notifications */
atomic64_t same_pages; /* no. of same element filled pages */
+ atomic64_t huge_pages; /* no. of huge pages */
atomic64_t pages_stored; /* no. of pages currently stored */
atomic_long_t max_used_pages; /* no. of maximum pages stored */
atomic64_t writestall; /* no. of write slow paths */
@@ -107,5 +112,8 @@ struct zram {
unsigned long nr_pages;
spinlock_t bitmap_lock;
#endif
+#ifdef CONFIG_ZRAM_MEMORY_TRACKING
+ struct dentry *debugfs_dir;
+#endif
};
#endif
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-02 09:32:04 +0000