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authorJim Keniston <jkenisto@linux.vnet.ibm.com>2011-03-22 23:35:12 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2011-03-23 00:44:17 (GMT)
commit565d76cb7d5fd7cb010fd690602280a69ab116ef (patch)
treebeff4279da00976e10145820c22e699192056973 /crypto
parentb12d12596992f608f5506a8dabe4d1299594bd1e (diff)
zlib: slim down zlib_deflate() workspace when possible
Instead of always creating a huge (268K) deflate_workspace with the maximum compression parameters (windowBits=15, memLevel=8), allow the caller to obtain a smaller workspace by specifying smaller parameter values. For example, when capturing oops and panic reports to a medium with limited capacity, such as NVRAM, compression may be the only way to capture the whole report. In this case, a small workspace (24K works fine) is a win, whether you allocate the workspace when you need it (i.e., during an oops or panic) or at boot time. I've verified that this patch works with all accepted values of windowBits (positive and negative), memLevel, and compression level. Signed-off-by: Jim Keniston <jkenisto@us.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: David Miller <davem@davemloft.net> Cc: Chris Mason <chris.mason@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'crypto')
-rw-r--r--crypto/deflate.c3
-rw-r--r--crypto/zlib.c18
2 files changed, 13 insertions, 8 deletions
diff --git a/crypto/deflate.c b/crypto/deflate.c
index cbc7a33..b5ccae2 100644
--- a/crypto/deflate.c
+++ b/crypto/deflate.c
@@ -48,7 +48,8 @@ static int deflate_comp_init(struct deflate_ctx *ctx)
int ret = 0;
struct z_stream_s *stream = &ctx->comp_stream;
- stream->workspace = vzalloc(zlib_deflate_workspacesize());
+ stream->workspace = vzalloc(zlib_deflate_workspacesize(
+ -DEFLATE_DEF_WINBITS, DEFLATE_DEF_MEMLEVEL));
if (!stream->workspace) {
ret = -ENOMEM;
goto out;
diff --git a/crypto/zlib.c b/crypto/zlib.c
index 739b8fc..d11d761 100644
--- a/crypto/zlib.c
+++ b/crypto/zlib.c
@@ -85,6 +85,7 @@ static int zlib_compress_setup(struct crypto_pcomp *tfm, void *params,
struct zlib_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
struct z_stream_s *stream = &ctx->comp_stream;
struct nlattr *tb[ZLIB_COMP_MAX + 1];
+ int window_bits, mem_level;
size_t workspacesize;
int ret;
@@ -94,7 +95,14 @@ static int zlib_compress_setup(struct crypto_pcomp *tfm, void *params,
zlib_comp_exit(ctx);
- workspacesize = zlib_deflate_workspacesize();
+ window_bits = tb[ZLIB_COMP_WINDOWBITS]
+ ? nla_get_u32(tb[ZLIB_COMP_WINDOWBITS])
+ : MAX_WBITS;
+ mem_level = tb[ZLIB_COMP_MEMLEVEL]
+ ? nla_get_u32(tb[ZLIB_COMP_MEMLEVEL])
+ : DEF_MEM_LEVEL;
+
+ workspacesize = zlib_deflate_workspacesize(window_bits, mem_level);
stream->workspace = vzalloc(workspacesize);
if (!stream->workspace)
return -ENOMEM;
@@ -106,12 +114,8 @@ static int zlib_compress_setup(struct crypto_pcomp *tfm, void *params,
tb[ZLIB_COMP_METHOD]
? nla_get_u32(tb[ZLIB_COMP_METHOD])
: Z_DEFLATED,
- tb[ZLIB_COMP_WINDOWBITS]
- ? nla_get_u32(tb[ZLIB_COMP_WINDOWBITS])
- : MAX_WBITS,
- tb[ZLIB_COMP_MEMLEVEL]
- ? nla_get_u32(tb[ZLIB_COMP_MEMLEVEL])
- : DEF_MEM_LEVEL,
+ window_bits,
+ mem_level,
tb[ZLIB_COMP_STRATEGY]
? nla_get_u32(tb[ZLIB_COMP_STRATEGY])
: Z_DEFAULT_STRATEGY);

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