Boot time with several filesystems on RPXlite DW
wd at denx.de
Tue Aug 10 17:41:46 EST 2004
In message <20040809145454.46774.qmail at web15609.mail.cnb.yahoo.com> you wrote:
> I used several filesystems based on MTD vs ramdisk to test boot time
> on RPXlite DW and got the following result:
> It seemed that Cramfs filesystem could get the most fast boot
> time.Also No matter how I tried,the boot time still exceeded 12
> seconds at least.But this result is not the same as Wolfgang said,5~6
> seconds boot time on 8xx board with 50MHZ core and bus frequency.Where
> did I go wrong?
There are many potential problems.
One thing that is obvious is:
You use an uncompressed kernel image, but have the CRC32 checksumming
enabled. This is counterproductive - the uncompressed image is nearly
3 times as big as a compressed one, so checksumming it will take
about 3 times as long.
If you want to go for speed and use an uncompressed image, you should
also turn off the CRC checksum test (by setting the U-Boot
environment variable "verify" to "no").
Then you may try increasing the console baudrate, or suppressing
console output completely (pass console=null to the Linux kernel).
Other issues are system dependent. Your system may not be optimized
for minimum access times for SDRAM and/or flash memory. Your system
might not be using 32 bit buswidth on SDRAM and/or flash. You may be
running on a processor which is slower because of small caches (like
a MPC850), etc. etc.
> I would be satisfied with less than 8 seconds in my case.Any ideas?
This is what I get using:
* A MPC860-T at 50 MHz CPU/50 MHz bus, 16 MB RAM.
* Our standard Linux kernel (uncompressed)
* Our standard (uncompressed) SELF image as included with the ELDK
* CRC32 verification turned off
0.090 ## Booting image at 40040000 ...
0.090 Image Name: Linux-2.4.4 uncompressed
0.091 Created: 2004-08-10 7:21:20 UTC
0.091 Image Type: PowerPC Linux Kernel Image (uncompressed)
0.091 Data Size: 1438656 Bytes = 1.4 MB
0.091 Load Address: 00000000
0.120 Entry Point: 00000000
0.201 ## Loading RAMDisk Image at 40200000 ...
0.201 Image Name: Simple Embedded Linux Framework
0.201 Created: 2004-08-10 7:23:35 UTC
0.201 Image Type: PowerPC Linux RAMDisk Image (uncompressed)
0.201 Data Size: 4194304 Bytes = 4 MB
0.270 Load Address: 00000000
0.270 Entry Point: 00000000
0.590 Loading Ramdisk to 00bad000, end 00fad000 ... OK
0.981 Linux version 2.4.4 (wd at atlas.denx.de) (gcc version 3.2.2 20030217 (Yellow Dog Linux 3.0 3.2.2-2a_1)) #2 Thu Jul 22 19:12:37 MEST 2004
0.981 On node 0 totalpages: 4096
0.981 zone(0): 4096 pages.
0.981 zone(1): 0 pages.
0.981 zone(2): 0 pages.
1.010 Kernel command line: root=/dev/ram rw ip=192.168.3.71:192.168.3.1::255.255.0.0:tqm8xx:eth0:off panic=1
1.010 Decrementer Frequency: 3125000
1.140 Calibrating delay loop... 49.86 BogoMIPS
1.140 Memory: 10356k available (1144k kernel code, 440k data, 52k init, 0k highmem)
1.201 Dentry-cache hash table entries: 2048 (order: 2, 16384 bytes)
1.201 Buffer-cache hash table entries: 1024 (order: 0, 4096 bytes)
1.201 Page-cache hash table entries: 4096 (order: 2, 16384 bytes)
1.201 Inode-cache hash table entries: 1024 (order: 1, 8192 bytes)
2.515 TQM flash bank 0: Using static image partition definition
2.515 Creating 4 MTD partitions on "TQM8xxL Bank 0":
2.516 0x00000000-0x00040000 : "u-boot"
2.516 0x00040000-0x00100000 : "kernel"
2.516 0x00100000-0x00200000 : "user"
2.516 0x00200000-0x00400000 : "initrd"
2.516 TQM flash bank 1: Using static file system partition definition
2.516 Creating 2 MTD partitions on "TQM8xxL Bank 1":
2.516 0x00000000-0x00200000 : "cramfs"
2.516 0x00200000-0x00400000 : "jffs"
2.516 NET4: Linux TCP/IP 1.0 for NET4.0
2.516 IP Protocols: ICMP, UDP, TCP
2.517 IP: routing cache hash table of 512 buckets, 4Kbytes
2.517 TCP: Hash tables configured (established 1024 bind 2048)
2.517 NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.
2.517 VFS: Mounted root (ext2 filesystem).
2.517 Freeing unused kernel memory: 52k init
6.533 ### Application running ...
Without any further optimization (like throwing out unused drivers,
disabling slow console output, using pre-calculated jiffies-per-
second etc.) your "phase I" is less than 1 second, your phase "II"
takes about 2.5 seconds, and your "phase III" takes 6.5 seconds - but
this is our standard image, which includes some slow operations (like
starting xinetd) which I normally woould try to avoid or at least
pospone until the critical parts of the applications have been
started. By just disabling xinetd you will see a boot time of 4..5
seconds on this system.
And as mentioned there is a long list of options to optimize the boot
As you can see there is no magic involved.
Software Engineering: Embedded and Realtime Systems, Embedded Linux
Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd at denx.de
panic: can't find /
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
More information about the Linuxppc-embedded