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From: Michael Lawnick <nospam_lawnick@gmx.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH] jffs2: cache data_crc results
Date: Tue, 14 Oct 2008 11:25:22 +0200	[thread overview]
Message-ID: <gd1oi3$c0c$1@ger.gmane.org> (raw)
In-Reply-To: <1223877234-720-7-git-send-email-yanok@emcraft.com>

Ilya Yanok said the following:
> 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 {

Could be so kind to give us your source reference?
I can't find above code in u-boot 1.3.3 nor 1.3.4

The same seems to apply to the other patches you've sent yesterday :-(

I'm eagerly waiting for summary patch ;-)

Regards,
Michael

  reply	other threads:[~2008-10-14  9:25 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-13  5:53 [U-Boot] [PATCH/RFC] Some speed improvements to U-Boot JFFS2 code Ilya Yanok
2008-10-13  5:53 ` [U-Boot] [PATCH] jffs2: add sector_size field to part_info structure Ilya Yanok
2008-10-13  8:17   ` Wolfgang Denk
2008-10-15 12:35     ` Ilya Yanok
2008-10-13  5:53 ` [U-Boot] [PATCH] jffs2: rewrite jffs2 scanning code based on Linux one Ilya Yanok
2008-10-13  5:53 ` [U-Boot] [PATCH] jffs2: summary support Ilya Yanok
2008-10-13  5:53 ` [U-Boot] [PATCH] jffs2: fix searching for latest version in jffs2_1pass_list_inodes() Ilya Yanok
2008-10-13  5:53 ` [U-Boot] [PATCH] jffs2: add buffer to cache flash accesses Ilya Yanok
2008-10-13  5:53 ` [U-Boot] [PATCH] jffs2: cache data_crc results Ilya Yanok
2008-10-14  9:25   ` Michael Lawnick [this message]
2008-10-13  8:14 ` [U-Boot] [PATCH/RFC] Some speed improvements to U-Boot JFFS2 code Wolfgang Denk
2008-10-15 12:44   ` Ilya Yanok
2008-10-16 12:36     ` Michael Lawnick
2008-11-01  1:00       ` Ilya Yanok
2008-11-02 16:02         ` Wolfgang Denk
2008-11-02 19:08           ` Ilya Yanok
2008-11-04 11:14         ` Michael Lawnick
2008-11-04 12:31           ` Michael Lawnick
2008-11-04 13:14             ` Joakim Tjernlund
2008-11-05  7:59               ` Michael Lawnick
2008-11-11  6:49             ` Alexey Neyman
2008-11-11  8:19               ` Joakim Tjernlund

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