Re: [microblaze-uclinux] FW: Memec 2VP7+Net with slow boot terminal

[John Williams <jwilliams@xxxxxxxxxxxxxx>]

Hi Rick,

Rick HORMIGO (L) wrote:

 > One thing I noted is that the version 2.4.27 I am using reports this 
caches in boot up.
 >
 > Dentry cache hash table entries: 4096 (order: 3, 32768 bytes)
 > Inode cache hash table entries: 2048 (order: 2, 16384 bytes)
 > Mount cache hash table entries: 512 (order: 0, 4096 bytes)
 > Buffer cache hash table entries: 1024 (order: 0, 4096 bytes)
 > Page-cache hash table entries: 8192 (order: 3, 32768 bytes)
 >
 > If I set or not  cache in the uclinux configuration doesn't change 
these numbers, but affects to the bogomips loop that goes
 > from 33 down to  3.8. I saw in other logs you guys reported they are 
more like:
 >
 > Dentry cache hash table entries: 2048 (order: 2, 16384 bytes)
 > Inode cache hash table entries: 1024 (order: 1, 8192 bytes)
 > Mount cache hash table entries: 512 (order: 0, 4096 bytes)
 > Buffer cache hash table entries: 1024 (order: 0, 4096 bytes)
 > Page-cache hash table entries: 4096 (order: 2, 16384 bytes)
 >
 >
 > Is this related to some in the kernel or strict to my mhs 
definitions? My hard defined cash is 16K+16K, however I saw the XC2V1K
 > mhs distribution doesn't set cache at all and stills most reports 
show cash.

These are software object caches maintained by the kernel, and are not 
related to the physical processor cache size that you configure in the 
MHS file.  To speed up allocation of commonly used data structures, such 
as inodes, dentrys and so on, the kernel maintains a cache of 
preallocated memory regions.  These are just reused and recycled as 
required.  This also helps prevent memory fragmentation.

The number of these object caches created is a function of the overall 
system memory, so I'd guess that the difference you see between your 
boot logs and those of a regular mbvanilla_net platform, are due to a 
difference in the amount of external RAM available.

Hope this helps,

John

___________________________
microblaze-uclinux mailing list
microblaze-uclinux@itee.uq.edu.au
Project Home Page : http://www.itee.uq.edu.au/~jwilliams/mblaze-uclinux
Mailing List Archive : http://www.itee.uq.edu.au/~listarch/microblaze-uclinux/