As we moved data_crc() invocation from jffs2_1pass_build_lists() to jffs2_1pass_read_inode() data_crc is going to be calculated on each inode access. This patch adds caching of data_crc() results. There is no significant improvement in speed (because of flash access caching added in previous patch I think, crc in RAM is really fast) but this patch impacts memory usage -- every b_node structure uses 12 bytes instead of 8.
Signed-off-by: Alexey Neyman avn@emcraft.com Signed-off-by: Ilya Yanok yanok@emcraft.com --- fs/jffs2/jffs2_1pass.c | 5 ++++- fs/jffs2/jffs2_private.h | 1 + 2 files changed, 5 insertions(+), 1 deletions(-)
diff --git a/fs/jffs2/jffs2_1pass.c b/fs/jffs2/jffs2_1pass.c index 9d9ac1a..b41c299 100644 --- a/fs/jffs2/jffs2_1pass.c +++ b/fs/jffs2/jffs2_1pass.c @@ -768,7 +768,10 @@ jffs2_1pass_read_inode(struct b_lists *pL, u32 inode, char *dest) put_fl_mem(jNode, pL->readbuf); continue; } - if (!data_crc(jNode)) { + if (b->datacrc == CRC_UNKNOWN) + b->datacrc = data_crc(jNode) ? + CRC_OK : CRC_BAD; + if (b->datacrc == CRC_BAD) { put_fl_mem(jNode, pL->readbuf); continue; } diff --git a/fs/jffs2/jffs2_private.h b/fs/jffs2/jffs2_private.h index b3fab1c..7a9eda6 100644 --- a/fs/jffs2/jffs2_private.h +++ b/fs/jffs2/jffs2_private.h @@ -7,6 +7,7 @@ struct b_node { u32 offset; struct b_node *next; + enum { CRC_UNKNOWN = 0, CRC_OK, CRC_BAD } datacrc; };
struct b_list {