This patch dramatically drops the amount of time u-boot needs to read a file from an ext2 partition. On a typical 2 to 5 MB file (kernels and initrds) it goes from tens of seconds to a couple seconds.
All we are doing here is grouping contiguous blocks into one read.
Boot tested on Globalscale Technologies Dreamplug (Kirkwood ARM SoC) with three different files. sha1sums were calculated in Linux userspace, and then confirmed after ext2load.
The following test results were provided by Eric Nelson:
Tested on i.MX6 Sabre Lite board loading a file of ~900k:
Without patch:
MX6QSABRELITE U-Boot > time ext2load sata 0:1 12000000 /usr/lib/libperl.so.5.12.4 && crc32 12000000 $filesize Loading file "/usr/lib/libperl.so.5.12.4" from sata device 0:1 (hda1) 958032 bytes read
time: 0.414 seconds, 414 ticks CRC32 for 12000000 ... 120e9e4f ==> 550deec9
With patch: MX6QSABRELITE U-Boot > time ext2load sata 0:1 12000000 /usr/lib/libperl.so.5.12.4 && crc32 12000000 $filesize Loading file "/usr/lib/libperl.so.5.12.4" from sata device 0:1 (hda1) 958032 bytes read
time: 0.205 seconds, 205 ticks CRC32 for 12000000 ... 120e9e4f ==> 550deec9
And, the following results were reported by Thierry Reding:
Before:
Tegra2 (Medcom) # time ext2load mmc 0 0x17000000 /boot/uImage Loading file "/boot/uImage" from mmc device 0:1 (xxa1) 5609104 bytes read
time: 4.638 seconds, 4638 ticks Tegra2 (Medcom) # crc32 0x17000000 559690 CRC32 for 17000000 ... 1755968f ==> 158788be
After:
Tegra2 (Medcom) # time ext2load mmc 0 0x17000000 /boot/uImage Loading file "/boot/uImage" from mmc device 0:1 (xxa1) 5609104 bytes read
time: 0.317 seconds, 317 ticks Tegra2 (Medcom) # crc32 0x17000000 559690 CRC32 for 17000000 ... 1755968f ==> 158788be
I can also successfully load the loaded uImage to a prompt
End results.
Signed-off-by: Jason Cooper u-boot@lakedaemon.net Tested-by: Eric Nelson eric.nelson@boundarydevices.com Tested-by: Thierry Reding thierry.reding@avionic-design.de --- Changes since v1: - updated commit entry to include test results from Eric Nelson and Thierry Reding
Based against tag 2012.04.01
fs/ext2/ext2fs.c | 26 ++++++++++++++++++++++++-- 1 files changed, 24 insertions(+), 2 deletions(-)
diff --git a/fs/ext2/ext2fs.c b/fs/ext2/ext2fs.c index f621741..f1fce48 100644 --- a/fs/ext2/ext2fs.c +++ b/fs/ext2/ext2fs.c @@ -420,7 +420,6 @@ int ext2fs_read_file if (blknr < 0) { return (-1); } - blknr = blknr << log2blocksize;
/* Last block. */ if (i == blockcnt - 1) { @@ -438,6 +437,29 @@ int ext2fs_read_file blockend -= skipfirst; }
+ /* grab middle blocks in one go */ + if (i != pos / blocksize && i != blockcnt - 1 && blockcnt > 3) { + int oldblk = blknr; + int blocknxt; + while (i < blockcnt - 1) { + blocknxt = ext2fs_read_block(node, i + 1); + if (blocknxt == (oldblk + 1)) { + oldblk = blocknxt; + i++; + } else { + blocknxt = ext2fs_read_block(node, i); + break; + } + } + + if (oldblk == blknr) + blockend = blocksize; + else + blockend = (1 + blocknxt - blknr) * blocksize; + } + + blknr = blknr << log2blocksize; + /* If the block number is 0 this block is not stored on disk but is zero filled instead. */ if (blknr) { @@ -450,7 +472,7 @@ int ext2fs_read_file } else { memset (buf, 0, blocksize - skipfirst); } - buf += blocksize - skipfirst; + buf += blockend - skipfirst; } return (len); }