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path: root/drivers/block/zram
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-rw-r--r--drivers/block/zram/Kconfig15
-rw-r--r--drivers/block/zram/zram_drv.c57
-rw-r--r--drivers/block/zram/zram_drv.h2
3 files changed, 41 insertions, 33 deletions
diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig
index 0386b7da02aa..7b29cce60ab2 100644
--- a/drivers/block/zram/Kconfig
+++ b/drivers/block/zram/Kconfig
@@ -59,8 +59,8 @@ config ZRAM_WRITEBACK
bool "Write back incompressible or idle page to backing device"
depends on ZRAM
help
- With incompressible page, there is no memory saving to keep it
- in memory. Instead, write it out to backing device.
+ This lets zram entries (incompressible or idle pages) be written
+ back to a backing device, helping save memory.
For this feature, admin should set up backing device via
/sys/block/zramX/backing_dev.
@@ -69,9 +69,18 @@ config ZRAM_WRITEBACK
See Documentation/admin-guide/blockdev/zram.rst for more information.
+config ZRAM_TRACK_ENTRY_ACTIME
+ bool "Track access time of zram entries"
+ depends on ZRAM
+ help
+ With this feature zram tracks access time of every stored
+ entry (page), which can be used for a more fine grained IDLE
+ pages writeback.
+
config ZRAM_MEMORY_TRACKING
bool "Track zRam block status"
depends on ZRAM && DEBUG_FS
+ select ZRAM_TRACK_ENTRY_ACTIME
help
With this feature, admin can track the state of allocated blocks
of zRAM. Admin could see the information via
@@ -86,4 +95,4 @@ config ZRAM_MULTI_COMP
This will enable multi-compression streams, so that ZRAM can
re-compress pages using a potentially slower but more effective
compression algorithm. Note, that IDLE page recompression
- requires ZRAM_MEMORY_TRACKING.
+ requires ZRAM_TRACK_ENTRY_ACTIME.
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index d77d3664ca08..2b1d82473be8 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -174,6 +174,14 @@ static inline u32 zram_get_priority(struct zram *zram, u32 index)
return prio & ZRAM_COMP_PRIORITY_MASK;
}
+static void zram_accessed(struct zram *zram, u32 index)
+{
+ zram_clear_flag(zram, index, ZRAM_IDLE);
+#ifdef CONFIG_ZRAM_TRACK_ENTRY_ACTIME
+ zram->table[index].ac_time = ktime_get_boottime();
+#endif
+}
+
static inline void update_used_max(struct zram *zram,
const unsigned long pages)
{
@@ -293,8 +301,9 @@ static void mark_idle(struct zram *zram, ktime_t cutoff)
zram_slot_lock(zram, index);
if (zram_allocated(zram, index) &&
!zram_test_flag(zram, index, ZRAM_UNDER_WB)) {
-#ifdef CONFIG_ZRAM_MEMORY_TRACKING
- is_idle = !cutoff || ktime_after(cutoff, zram->table[index].ac_time);
+#ifdef CONFIG_ZRAM_TRACK_ENTRY_ACTIME
+ is_idle = !cutoff || ktime_after(cutoff,
+ zram->table[index].ac_time);
#endif
if (is_idle)
zram_set_flag(zram, index, ZRAM_IDLE);
@@ -317,7 +326,7 @@ static ssize_t idle_store(struct device *dev,
*/
u64 age_sec;
- if (IS_ENABLED(CONFIG_ZRAM_MEMORY_TRACKING) && !kstrtoull(buf, 0, &age_sec))
+ if (IS_ENABLED(CONFIG_ZRAM_TRACK_ENTRY_ACTIME) && !kstrtoull(buf, 0, &age_sec))
cutoff_time = ktime_sub(ktime_get_boottime(),
ns_to_ktime(age_sec * NSEC_PER_SEC));
else
@@ -841,12 +850,6 @@ static void zram_debugfs_destroy(void)
debugfs_remove_recursive(zram_debugfs_root);
}
-static void zram_accessed(struct zram *zram, u32 index)
-{
- zram_clear_flag(zram, index, ZRAM_IDLE);
- zram->table[index].ac_time = ktime_get_boottime();
-}
-
static ssize_t read_block_state(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
@@ -930,10 +933,6 @@ 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)
-{
- zram_clear_flag(zram, index, ZRAM_IDLE);
-};
static void zram_debugfs_register(struct zram *zram) {};
static void zram_debugfs_unregister(struct zram *zram) {};
#endif
@@ -1254,7 +1253,7 @@ static void zram_free_page(struct zram *zram, size_t index)
{
unsigned long handle;
-#ifdef CONFIG_ZRAM_MEMORY_TRACKING
+#ifdef CONFIG_ZRAM_TRACK_ENTRY_ACTIME
zram->table[index].ac_time = 0;
#endif
if (zram_test_flag(zram, index, ZRAM_IDLE))
@@ -1322,9 +1321,9 @@ static int zram_read_from_zspool(struct zram *zram, struct page *page,
void *mem;
value = handle ? zram_get_element(zram, index) : 0;
- mem = kmap_atomic(page);
+ mem = kmap_local_page(page);
zram_fill_page(mem, PAGE_SIZE, value);
- kunmap_atomic(mem);
+ kunmap_local(mem);
return 0;
}
@@ -1337,14 +1336,14 @@ static int zram_read_from_zspool(struct zram *zram, struct page *page,
src = zs_map_object(zram->mem_pool, handle, ZS_MM_RO);
if (size == PAGE_SIZE) {
- dst = kmap_atomic(page);
+ dst = kmap_local_page(page);
memcpy(dst, src, PAGE_SIZE);
- kunmap_atomic(dst);
+ kunmap_local(dst);
ret = 0;
} else {
- dst = kmap_atomic(page);
+ dst = kmap_local_page(page);
ret = zcomp_decompress(zstrm, src, size, dst);
- kunmap_atomic(dst);
+ kunmap_local(dst);
zcomp_stream_put(zram->comps[prio]);
}
zs_unmap_object(zram->mem_pool, handle);
@@ -1417,21 +1416,21 @@ static int zram_write_page(struct zram *zram, struct page *page, u32 index)
unsigned long element = 0;
enum zram_pageflags flags = 0;
- mem = kmap_atomic(page);
+ mem = kmap_local_page(page);
if (page_same_filled(mem, &element)) {
- kunmap_atomic(mem);
+ kunmap_local(mem);
/* Free memory associated with this sector now. */
flags = ZRAM_SAME;
atomic64_inc(&zram->stats.same_pages);
goto out;
}
- kunmap_atomic(mem);
+ kunmap_local(mem);
compress_again:
zstrm = zcomp_stream_get(zram->comps[ZRAM_PRIMARY_COMP]);
- src = kmap_atomic(page);
+ src = kmap_local_page(page);
ret = zcomp_compress(zstrm, src, &comp_len);
- kunmap_atomic(src);
+ kunmap_local(src);
if (unlikely(ret)) {
zcomp_stream_put(zram->comps[ZRAM_PRIMARY_COMP]);
@@ -1495,10 +1494,10 @@ compress_again:
src = zstrm->buffer;
if (comp_len == PAGE_SIZE)
- src = kmap_atomic(page);
+ src = kmap_local_page(page);
memcpy(dst, src, comp_len);
if (comp_len == PAGE_SIZE)
- kunmap_atomic(src);
+ kunmap_local(src);
zcomp_stream_put(zram->comps[ZRAM_PRIMARY_COMP]);
zs_unmap_object(zram->mem_pool, handle);
@@ -1615,9 +1614,9 @@ static int zram_recompress(struct zram *zram, u32 index, struct page *page,
num_recomps++;
zstrm = zcomp_stream_get(zram->comps[prio]);
- src = kmap_atomic(page);
+ src = kmap_local_page(page);
ret = zcomp_compress(zstrm, src, &comp_len_new);
- kunmap_atomic(src);
+ kunmap_local(src);
if (ret) {
zcomp_stream_put(zram->comps[prio]);
diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index d090753f97be..3b94d12f41b4 100644
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -69,7 +69,7 @@ struct zram_table_entry {
unsigned long element;
};
unsigned long flags;
-#ifdef CONFIG_ZRAM_MEMORY_TRACKING
+#ifdef CONFIG_ZRAM_TRACK_ENTRY_ACTIME
ktime_t ac_time;
#endif
};