diff options
| -rw-r--r-- | fs/ubifs/compress.c | 6 | ||||
| -rw-r--r-- | fs/ubifs/ubifs-media.h | 7 |
2 files changed, 10 insertions, 3 deletions
diff --git a/fs/ubifs/compress.c b/fs/ubifs/compress.c index a0ada596b17c..6414d50780e1 100644 --- a/fs/ubifs/compress.c +++ b/fs/ubifs/compress.c @@ -119,10 +119,10 @@ void ubifs_compress(const void *in_buf, int in_len, void *out_buf, int *out_len, } /* - * Presently, we just require that compression results in less data, - * rather than any defined minimum compression ratio or amount. + * If the data compressed only slightly, it is better to leave it + * uncompressed to improve read speed. */ - if (ALIGN(*out_len, 8) >= ALIGN(in_len, 8)) + if (in_len - *out_len < UBIFS_MIN_COMPRESS_DIFF) goto no_compr; return; diff --git a/fs/ubifs/ubifs-media.h b/fs/ubifs/ubifs-media.h index 0b378042a3a2..b25fc36cf72f 100644 --- a/fs/ubifs/ubifs-media.h +++ b/fs/ubifs/ubifs-media.h @@ -51,6 +51,13 @@ */ #define UBIFS_MIN_COMPR_LEN 128 +/* + * If compressed data length is less than %UBIFS_MIN_COMPRESS_DIFF bytes + * shorter than uncompressed data length, UBIFS preferes to leave this data + * node uncompress, because it'll be read faster. + */ +#define UBIFS_MIN_COMPRESS_DIFF 64 + /* Root inode number */ #define UBIFS_ROOT_INO 1 |