Hi Leo,
> This patch make the JFFS2 scanning faster in U-Boot.
> 1). if we find 1KB 0xFF data from the beginning of the erase block,skip it.
> 2). if the 1KB data is 0xFF after the cleanmarker, ship this erase block.
Ship it to where? ;) Typo, should be skip.
> For the 16MB nor flash, the scanning time is changed from about 9s to 1s.
>
> Signed-off-by: Leo Liu <liucai....@gmail.com>
checkpatch says:
total: 7 errors, 9 warnings, 103 lines checked
NOTE: whitespace errors detected, you may wish to use scripts/cleanpatch or
scripts/cleanfile
Is there a corresponding thing in the Linux kernel?
> ---
> fs/jffs2/jffs2_1pass.c | 31 +++++++++++++++++++++----------
> fs/jffs2/jffs2_nand_1pass.c | 2 +-
> 2 files changed, 22 insertions(+), 11 deletions(-)
>
> diff --git a/fs/jffs2/jffs2_1pass.c b/fs/jffs2/jffs2_1pass.c
> index dfb1745..f38f755 100644
> --- a/fs/jffs2/jffs2_1pass.c
> +++ b/fs/jffs2/jffs2_1pass.c
> @@ -1441,7 +1441,7 @@ dump_dirents(struct b_lists *pL)
> }
> #endif
>
> -#define DEFAULT_EMPTY_SCAN_SIZE 4096
> +#define DEFAULT_EMPTY_SCAN_SIZE 1024
Hm, this is not mentioned in the commit log. So is this detection
already there and you simply decrease the amount of empty space you are
looking for?
>
> static inline uint32_t EMPTY_SCAN_SIZE(uint32_t sector_size)
> {
> @@ -1461,7 +1461,7 @@ jffs2_1pass_build_lists(struct part_info * part)
> u32 counter4 = 0;
> u32 counterF = 0;
> u32 counterN = 0;
> - u32 buf_size = DEFAULT_EMPTY_SCAN_SIZE;
> + u32 buf_size = 128*1024;;
This is a 128k buffer size which previously was a 4k buffer. Why is
this change needed? Where does the size come from?
> char *buf;
>
> /* turn off the lcd. Refreshing the lcd adds 50% overhead to the */
> @@ -1559,14 +1559,17 @@ jffs2_1pass_build_lists(struct part_info * part)
> /* We temporarily use 'ofs' as a pointer into the buffer/jeb */
> ofs = 0;
>
> - /* Scan only 4KiB of 0xFF before declaring it's empty */
> + /* Scan only 1KiB of 0xFF before declaring it's empty */
Change the comment to refer to the macro so we don't need to change it
every time the macro changes.
> while (ofs < EMPTY_SCAN_SIZE(part->sector_size) &&
> *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
> ofs += 4;
>
> - if (ofs == EMPTY_SCAN_SIZE(part->sector_size))
> + if (ofs == EMPTY_SCAN_SIZE(part->sector_size)) {
> + printf("Block at 0x%08x is empty (erased)\n",
> sector_ofs);
Hm, you add this output so lets consider what it says - wouldn't it be
better to say "is considered to be empty"? After all, we only infer the
emptiness in the code.
> continue;
> + }
>
> + /* Now ofs is a complete physical flash offset as it always
> was... */
> ofs += sector_ofs;
> prevofs = ofs - 1;
>
> @@ -1594,16 +1597,14 @@ jffs2_1pass_build_lists(struct part_info * part)
>
> if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
> uint32_t inbuf_ofs;
> - uint32_t empty_start, scan_end;
> + uint32_t empty_start;
>
> empty_start = ofs;
> ofs += 4;
> - scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(
> - part->sector_size)/8,
> - buf_len);
> +
> more_empty:
> inbuf_ofs = ofs - buf_ofs;
> - while (inbuf_ofs < scan_end) {
> + while (inbuf_ofs < buf_len) {
> if (*(uint32_t *)(&buf[inbuf_ofs]) !=
> 0xffffffff)
> goto scan_more;
> @@ -1613,6 +1614,12 @@ jffs2_1pass_build_lists(struct part_info * part)
> }
> /* Ran off end. */
>
> + /* If we're only checking the beginning of a
> block with a cleanmarker,
> + bail now */
> + if((buf_ofs == sector_ofs) &&
> + (node ==(struct jffs2_unknown_node
> *)&buf[ofs-buf_ofs]))
> + break;
> +
> /* See how much more there is to read in this
> * eraseblock...
> */
> @@ -1627,12 +1634,12 @@ jffs2_1pass_build_lists(struct part_info * part)
> */
> break;
> }
> - scan_end = buf_len;
> get_fl_mem((u32)part->offset + ofs, buf_len,
> buf);
> buf_ofs = ofs;
> goto more_empty;
> }
> +
> if (node->magic != JFFS2_MAGIC_BITMASK ||
> !hdr_crc(node)) {
> ofs += 4;
> @@ -1650,6 +1657,8 @@ jffs2_1pass_build_lists(struct part_info * part)
> case JFFS2_NODETYPE_INODE:
> if (buf_ofs + buf_len < ofs + sizeof(struct
> jffs2_raw_inode)) {
> + buf_len = min_t(uint32_t, buf_size,
> sector_ofs
> + + part->sector_size -
> ofs);
>
> get_fl_mem((u32)part->offset + ofs,
> buf_len, buf);
> buf_ofs = ofs;
> @@ -1671,6 +1680,8 @@ jffs2_1pass_build_lists(struct part_info * part)
> ((struct
> jffs2_raw_dirent *)
> node)->nsize) {
> + buf_len = min_t(uint32_t, buf_size,
> sector_ofs
> + + part->sector_size -
> ofs);
>
> get_fl_mem((u32)part->offset + ofs,
> buf_len, buf);
> buf_ofs = ofs;
> diff --git a/fs/jffs2/jffs2_nand_1pass.c b/fs/jffs2/jffs2_nand_1pass.c
> index e3bc536..16bb2e9 100644
> --- a/fs/jffs2/jffs2_nand_1pass.c
> +++ b/fs/jffs2/jffs2_nand_1pass.c
> @@ -833,7 +833,7 @@ jffs2_1pass_build_lists(struct part_info * part)
> return 0;
>
> ofs = 0;
> - /* Scan only 4KiB of 0xFF before declaring it's empty */
> + /* Scan only 1KiB of 0xFF before declaring it's empty */
> while (ofs < EMPTY_SCAN_SIZE && *(uint32_t *)(&buf[ofs]) ==
> 0xFFFFFFFF)
> ofs += 4;
> if (ofs == EMPTY_SCAN_SIZE)
On a whole - is this optimization safe with regard to uncompressed files
containing only 0xFFs?
Cheers
Detlev
--
"One of my most productive days was throwing away 1000 lines of code."
- Ken Thompson.
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: d...@denx.de
_______________________________________________
U-Boot mailing list
U-Boot@lists.denx.de
http://lists.denx.de/mailman/listinfo/u-boot
