Subject: [PATCH 6/6] nvram: Shrink our zlib_deflate workspace from 268K to 24K

From: Jim Keniston <[email-masked]>
Date: Sat, 13 Nov 2010 20:15:44 -0800

Exploit zlib_deflate_workspacesize2() to create a much smaller
zlib_deflate workspace when capturing oops/panic reports to NVRAM.

Signed-off-by: Jim Keniston <[email-masked]>
---

 arch/powerpc/platforms/pseries/nvram.c |   11 +++++++----
 1 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/nvram.c b/arch/powerpc/platforms/pseries/nvram.c
index 8e5ed74..6409cb6 100644
--- a/arch/powerpc/platforms/pseries/nvram.c
+++ b/arch/powerpc/platforms/pseries/nvram.c
@@ -17,7 +17,6 @@
 #include <linux/init.h>
 #include <linux/spinlock.h>
 #include <linux/slab.h>
-#include <linux/vmalloc.h>
 #include <linux/ctype.h>
 #include <linux/kmsg_dump.h>
 #include <linux/zlib.h>
@@ -94,6 +93,8 @@ static struct oops_parition_data {
 } *little_oops_buf;
 
 #define COMPR_LEVEL 6
+#define WINDOW_BITS 12
+#define MEM_LEVEL 4
 static struct z_stream_s stream;
 
 static ssize_t pSeries_nvram_read(char *buf, size_t count, loff_t *index)
@@ -408,7 +409,8 @@ static void __init nvram_init_oops_partition(int rtas_partition_exists)
 	big_oops_buf_sz = (little_oops_buf_sz * 100) / 45;
 	big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
 	if (big_oops_buf) {
-		stream.workspace = vmalloc(zlib_deflate_workspacesize());
+		stream.workspace = kmalloc(zlib_deflate_workspacesize2(
+				WINDOW_BITS, MEM_LEVEL), GFP_KERNEL);
 		if (!stream.workspace) {
 			pr_err("nvram: No memory for compression workspace; "
 				"skipping compression of %s partition data\n",
@@ -427,7 +429,7 @@ static void __init nvram_init_oops_partition(int rtas_partition_exists)
 		pr_err("nvram: kmsg_dump_register() failed; returned %d\n", rc);
 		kfree(little_oops_buf);
 		kfree(big_oops_buf);
-		vfree(stream.workspace);
+		kfree(stream.workspace);
 	}
 }
 
@@ -625,7 +627,8 @@ static int nvram_compress(const void *in, void *out, size_t inlen,
 	int err, ret;
 
 	ret = -EIO;
-	err = zlib_deflateInit(&stream, COMPR_LEVEL);
+	err = zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS,
+						MEM_LEVEL, Z_DEFAULT_STRATEGY);
 	if (err != Z_OK)
 		goto error;