Add ZLIB backend (disabled yet, will be enalbed in later patch).
======================================================================
TEST
Copy dir with the linux kernel to a zram device (du -sh 2.3G) and check
memory usage stats.
mm_stat fields:
orig_data_size
compr_data_size
mem_used_total
mem_limit
mem_used_max
zero_pages
num_migrated
zlib
cat /sys/block/zram0/mm_stat
2522685440 1210486447 1230729216 0 1230729216 5461 0
lzo
cat /sys/block/zram0/mm_stat
2525872128 1713351248 1738387456 0 1738387456 4682 0
ZLIB uses 484+MiB less memory in the test.
Signed-off-by: Sergey Senozhatsky <[email protected]>
---
drivers/block/zram/Makefile | 1 +
drivers/block/zram/zcomp.c | 11 ++++
drivers/block/zram/zcomp.h | 2 +
drivers/block/zram/zcomp_zlib.c | 120 ++++++++++++++++++++++++++++++++++++++++
drivers/block/zram/zcomp_zlib.h | 17 ++++++
5 files changed, 151 insertions(+)
create mode 100644 drivers/block/zram/zcomp_zlib.c
create mode 100644 drivers/block/zram/zcomp_zlib.h
diff --git a/drivers/block/zram/Makefile b/drivers/block/zram/Makefile
index be0763f..0922f54 100644
--- a/drivers/block/zram/Makefile
+++ b/drivers/block/zram/Makefile
@@ -1,5 +1,6 @@
zram-y := zcomp_lzo.o zcomp.o zram_drv.o
zram-$(CONFIG_ZRAM_LZ4_COMPRESS) += zcomp_lz4.o
+zram-$(CONFIG_ZRAM_ZLIB_COMPRESS) += zcomp_zlib.o
obj-$(CONFIG_ZRAM) += zram.o
diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
index a1c67be..a0cef0b 100644
--- a/drivers/block/zram/zcomp.c
+++ b/drivers/block/zram/zcomp.c
@@ -19,6 +19,9 @@
#ifdef CONFIG_ZRAM_LZ4_COMPRESS
#include "zcomp_lz4.h"
#endif
+#ifdef CONFIG_ZRAM_ZLIB_COMPRESS
+#include "zcomp_zlib.h"
+#endif
/*
* single zcomp_strm backend
@@ -48,6 +51,9 @@ static struct zcomp_backend *backends[] = {
#ifdef CONFIG_ZRAM_LZ4_COMPRESS
&zcomp_lz4,
#endif
+#ifdef CONFIG_ZRAM_ZLIB_COMPRESS
+ &zcomp_zlib,
+#endif
NULL
};
@@ -328,11 +334,16 @@ void zcomp_destroy(struct zcomp *comp)
void *zcomp_decompress_begin(struct zcomp *comp)
{
+ if (unlikely(comp->backend->flags() & ZCOMP_NEED_READ_ZSTRM))
+ return zcomp_strm_find(comp);
+
return NULL;
}
void zcomp_decompress_end(struct zcomp *comp, void *private)
{
+ if (unlikely(private))
+ zcomp_strm_release(comp, private);
}
/*
diff --git a/drivers/block/zram/zcomp.h b/drivers/block/zram/zcomp.h
index 5cb9a0b..dbb7f1f 100644
--- a/drivers/block/zram/zcomp.h
+++ b/drivers/block/zram/zcomp.h
@@ -12,6 +12,8 @@
#include <linux/mutex.h>
+#define ZCOMP_NEED_READ_ZSTRM (1 << 0)
+
struct zcomp_strm {
/* compression/decompression buffer */
void *buffer;
diff --git a/drivers/block/zram/zcomp_zlib.c b/drivers/block/zram/zcomp_zlib.c
new file mode 100644
index 0000000..711eddd
--- /dev/null
+++ b/drivers/block/zram/zcomp_zlib.c
@@ -0,0 +1,120 @@
+/*
+ * Copyright (C) 2015 Sergey Senozhatsky.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/zlib.h>
+
+#include "zcomp_zlib.h"
+
+#define ZLIB_COMPRESSION_LEVEL 3
+
+static void *zlib_create(void)
+{
+ z_stream *stream;
+ size_t size;
+
+ stream = kzalloc(sizeof(*stream), GFP_KERNEL);
+ if (!stream)
+ return NULL;
+
+ size = max(zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL),
+ zlib_inflate_workspacesize());
+ stream->workspace = vmalloc(size);
+ if (!stream->workspace) {
+ kfree(stream);
+ stream = NULL;
+ }
+
+ return stream;
+}
+
+static void zlib_destroy(void *private)
+{
+ z_stream *stream = private;
+
+ vfree(stream->workspace);
+ kfree(stream);
+}
+
+static int zlib_flags(void)
+{
+ return ZCOMP_NEED_READ_ZSTRM;
+}
+
+static int zlib_compress(const unsigned char *src, unsigned char *dst,
+ size_t *dst_len, void *private)
+{
+ z_stream *stream = private;
+ int err;
+
+ err = zlib_deflateInit(stream, ZLIB_COMPRESSION_LEVEL);
+ if (err != Z_OK)
+ goto out;
+
+ stream->next_in = src;
+ stream->avail_in = PAGE_SIZE;
+ stream->total_in = 0;
+ stream->next_out = dst;
+ stream->avail_out = PAGE_SIZE;
+ stream->total_out = 0;
+
+ err = zlib_deflate(stream, Z_FINISH);
+ if (err != Z_STREAM_END)
+ goto out;
+
+ err = zlib_deflateEnd(stream);
+ if (err != Z_OK)
+ goto out;
+
+ if (stream->total_out >= stream->total_in)
+ goto out;
+
+ *dst_len = stream->total_out;
+out:
+ return err == Z_OK ? 0 : err;
+}
+
+static int zlib_decompress(const unsigned char *src, size_t src_len,
+ unsigned char *dst, void *private)
+{
+ z_stream *stream = private;
+ int err;
+
+ err = zlib_inflateInit(stream);
+ if (err != Z_OK)
+ goto out;
+
+ stream->next_in = src;
+ stream->avail_in = src_len;
+ stream->total_in = 0;
+ stream->next_out = dst;
+ stream->avail_out = PAGE_SIZE;
+ stream->total_out = 0;
+
+ err = zlib_inflate(stream, Z_FINISH);
+ if (err != Z_STREAM_END)
+ goto out;
+
+ err = zlib_inflateEnd(stream);
+ if (err != Z_OK)
+ goto out;
+out:
+ return err == Z_OK ? 0 : err;
+}
+
+struct zcomp_backend zcomp_zlib = {
+ .compress = zlib_compress,
+ .decompress = zlib_decompress,
+ .create = zlib_create,
+ .destroy = zlib_destroy,
+ .flags = zlib_flags,
+ .name = "zlib",
+};
diff --git a/drivers/block/zram/zcomp_zlib.h b/drivers/block/zram/zcomp_zlib.h
new file mode 100644
index 0000000..d0e4fa0
--- /dev/null
+++ b/drivers/block/zram/zcomp_zlib.h
@@ -0,0 +1,17 @@
+/*
+ * Copyright (C) 2015 Sergey Senozhatsky.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _ZCOMP_ZLIB_H_
+#define _ZCOMP_ZLIB_H_
+
+#include "zcomp.h"
+
+extern struct zcomp_backend zcomp_zlib;
+
+#endif /* _ZCOMP_ZLIB_H_ */
--
2.5.0
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
