2008/10/5 Greg Ungerer <g...@snapgear.com <mailto:g...@snapgear.com>>
Hi Alexander,
Alexander Eremeenkov wrote:
I have performance problems with applications on this
kernel(uClinux 2.6.25-uc0).
First of all, I have custom made board with this features:
ColdFire 5274 @ 150 MHz
External Bus Frequency 75 MHz
uClinux 2.6.25 boot up and work perfectly stable, but very slow.
For this board i have also 2.4.x kernel compiled, and it works
more faster ( ~ 2-20 times faster, if different test application).
After reading maillist, i find, that some people have equals
problems, and their reason were - disabled cache. But in my
case, cache enabled in start process normally.
Calibration delay calculate good value:
Calibrating delay loop... 98.71 BogoMIPS (lpj=493568)
Also, if i disabled cache in /include/asm-m68knommu/mcfcache.h,
i got looks-like normal, with disabled cache, value:
Calibrating delay loop... 5.82 BogoMIPS
So, I have drawn a conclusion, that cache enables good.
Now, about performance. I test it with some applications.
1. Dhrystone test. With it, i have 4065 dhrystones/second, that
critically small for this CPU. But i curious, that, when a
disabled cache, the result same.. As though like cache at just
flushed or worked incorrect.
2. Simple forever cycle with 1 value in memory incremented. This
test, also show near ~5 real MISP performance.
When i try to watch assess to external memory by CPU, i saw,
that, it work with external RAM(where this application contain)
everytime - but i think that, simple application with 5 command
+ 1 value memory must being in cache, and CPU must work with
cache only.
3. Some real/work application. They do massive processing/moving
data, working with peripheral, etc. I also have quite bad
performance. Those applications runs at 2.4.x kernel at ~4 times
faster.
So, conclusion with it.
1) I think, that i can't have problems with hardware - because,
2.4.x kernel work fast.
2) I have enabled cache at start process - 98 BogoMIPS good
value for my CPU, also 2.4 kernel calculate same result.
Now i have question, maybe somebody have same problems at this
kernel?
Maybe 2.6.xx so slow, and ways to speed up it use old kernel or
modern/faster CPU?Maybe some bugs in poring it to ColdFire
family?Etc?
There is no reason that application code performance (independant of
use of kernel system calls) should give noticably different results
on a 2.6 kernel vs a 2.4 kernel.
Maybe it problem with cache at working process? Some drivers,
for example, can flush cache..anyone have equal problem? About
it, i will check it with kernel build for 5275EVB, but i think,
that result will be same, because, a removed all i can
drivers/modules form kernel, that almost "empty" kernel starts,
and after it i run Dhrystone test, and get same result.
Maybe it's a toolchain problem? I use
m68k-uclinux-tools-20061214.sh, they have some minor problems,
maybe reason with they? But, my second test with simple
application excludes this variant.
If someone had those problems I will be glad for any help.
I recall a problem a little while back where the cache flush code
was changing the cache configuration and not just flushing. (I think
it was the 5282 cache support code that was broken). In this scenario
the initial cache setup was good (so everything was fast), and after
the first cache flush the setup was wrong. Now that would make something
like the bogomips calculation look good, but later performance bad
Looking at the 2 places this is done:
linux-2.6.x/include/asm-m68knommu/mcfcache.h
linux-2.6.x/include/asm-m68knommu/cacheflush.h
I suspect this may have broken the cache support for the 527x
series (so the 5270/5271 and 5274/5275).
To verify if this is what you are seeing, can you change the cache
flush code for CONFIG_M527x in cacheflush.h from:
"movel #0x81000200, %%d0\n\t"
to
"movel #0x81400100, %%d0\n\t"
This is just to prove this is the problem. A real fix would
need the 528x and 527x cache flushing code separated out.
Regards
Greg
And my kernel messages at result:
/> cat /proc/kmsg
<5>Linux version 2.6.25-uc0 (wa...@arch) (gcc version 4.1.1) #36
Mon Jan 5 13:05:16 PST 9
<6>
<4>
<4>uClinux/COLDFIRE(m5274/5275)
<6>COLDFIRE port done by Greg Ungerer, g...@snapgear.com
<mailto:g...@snapgear.com> <6>Flat
model support (C) 1998,1999 Kenneth Albanowski, D. Jeff Dionne
<7>On node 0 totalpages: 8192
<7> DMA zone: 0 pages used
for memmap <7>
Normal zone: 64 pages used for memmap
<7> Normal zone: 8128 pages, LIFO batch:0
<7> Movable zone: 0
pages used for memmap
<4>Built 1 zonelists in Zone order, mobility grouping on.
Total pages: 8128 <5>Kernel command line:
<6>Dentry cache hash table entries: 4096 (order: 2,
16384 bytes) <6>Inode-cache hash table
entries: 2048 (order: 1, 8192 bytes)
<6>Memory available: 29264k/32768k RAM, (1504k kernel code, 243k
data) <7>Calibrating delay loop... 98.71
BogoMIPS (lpj=493568)
<4>Mount-cache hash table entries: 512
<6>net_namespace: 144 bytes
<6>NET: Registered
protocol family 16
<6>NET: Registered protocol family 2
<6>IP route cache hash table entries:
1024 (order: 0, 4096 bytes) <6>TCP
established hash table entries: 1024 (order: 1, 8192 bytes)
<6>TCP bind hash table entries: 1024 (order: 0,
4096 bytes) <6>TCP: Hash tables
configured (established 1024 bind 1024)
<6>TCP reno registered
<6>Installing knfsd (copyright (C)
1996 o...@monad.swb.de <mailto:o...@monad.swb.de>).
<6>JFFS2 version 2.2. (NAND) ?? 2001-2006 Red
Hat, Inc. <6>io scheduler noop
registered
<6>io scheduler cfq registered (default)
<4>ColdFire
internal UART serial driver
<6>ttyS0 at MMIO 0x40000200 (irq = 77) is a ColdFire
UART <6>console [ttyS0] enabled
<6>ttyS1
at MMIO 0x40000240 (irq = 78) is a ColdFire UART
<6>ttyS2 at MMIO 0x40000280 (irq = 79) is a
ColdFire UART <6>brd: module loaded
<4>FEC ENET Version 0.2
<4>fec: PHY @ 0x1, ID 0x20005c90 --
DP83848 <4>eth0:
ethernet 00:04:24:23:34:44
<4>uclinux[mtd]: RAM probe address=0x1d50f4
size=0x14d000 <5>Creating 1 MTD
partitions on "RAM":
<5>0x00000000-0x0014d000 : "ROMfs"
<4>uclinux[mtd]: set ROMfs to be root
filesystem
<6>Physically mapped flash: Found 1 x16 devices at 0x0 in
16-bit bank <4> Intel/Sharp Extended Query
Table at 0x010A <4>
Intel/Sharp Extended Query Table at 0x010A
<4> Intel/Sharp Extended Query Table at 0x010A
<4> Intel/Sharp Extended
Query Table at 0x010A
<4> Intel/Sharp Extended Query Table at 0x010A
<6>Using buffer write method
<6>Using auto-unlock
on power-up/resume
<5>cfi_cmdset_0001: Erase suspend on write enabled
<7>erase region 0:
offset=0x0,size=0x8000,blocks=4
<7>erase region 1: offset=0x20000,size=0x20000,blocks=63
<6>TCP cubic registered
<6>NET: Registered protocol family
1 <6>RPC:
Registered udp transport module.
<6>RPC: Registered tcp transport module.
<6>NET: Registered protocol
family 33
<4>VFS: Mounted root (romfs filesystem) readonly.
<5>Freeing unused kernel memory: 52k
freed (0x1a7000 - 0x1b3000) <4>eth0:
config: auto-negotiation on, 100FDX, 100HDX, 10FDX, 10HDX.
--
------------------------------------------------------------------------
Greg Ungerer -- Principal Engineer EMAIL:
g...@snapgear.com <mailto:g...@snapgear.com>
SnapGear, a McAfee Company PHONE: +61 7 3435 2888
825 Stanley St, FAX: +61 7 3891 3630
Woolloongabba, QLD, 4102, Australia WEB: http://www.SnapGear.com
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