(panic) Lots of network memory needed

[Karim Fodil-Lemelin]

Thanks but the system still crashes (FreeBSD 4.9) with 131072. Here is a 
backtrace showing just that:

Debugger (msg=0xc02b6cdb "panic") at ../../i386/i386/db_interface.c:321
321     }
(kgdb) bt
#0  Debugger (msg=0xc02b6cdb "panic") at ../../i386/i386/db_interface.c:321
#1  0xc016a230 in panic (
    fmt=0xc02ea380 "pmap_enter: invalid page directory pdir=%#llx, 
va=%#x\n")
    at ../../kern/kern_shutdown.c:593
#2  0xc0283594 in pmap_enter (pmap=0xc0340460, va=4292141056, m=0xc24b2848,
    prot=7 '\a', wired=1) at ../../i386/i386/pmap.c:1943
#3  0xc023ddd0 in vm_fault (map=0xc033322c, vaddr=4292141056,
    fault_type=7 '\a', fault_flags=1) at ../../vm/vm_fault.c:841
#4  0xc023df0a in vm_fault_wire (map=0xc033322c, start=4292141056,
    end=4292149248) at ../../vm/vm_fault.c:915
#5  0xc0240831 in vm_map_pageable (map=0xc033322c, start=4292141056,
    real_end=4292149248, new_pageable=0) at ../../vm/vm_map.c:1817
#6  0xc023ea25 in kmem_alloc (map=0xc033322c, size=8192)
    at ../../vm/vm_kern.c:213
#7  0xc024a46f in _zget (z=0xdb5c6e80) at ../../vm/vm_zone.c:425
#8  0xc024a269 in zalloc (z=0xdb5c6e80) at ../../vm/vm_zone.c:60
#9  0xc0196106 in namei (ndp=0xfa489ef4) at ../../kern/vfs_lookup.c:104
#10 0xc01614ca in execve (p=0xfa482e00, uap=0xfa489f90)
    at ../../kern/kern_exec.c:165
#11 0xc01590a1 in start_init (dummy=0x0) at ../../kern/init_main.c:543
(kgdb) p nmbclusters
$1 = 131072
(kgdb)

Goran Spirovski - MorEl On.net wrote:

>AFAIK the number of mbufs (and consequently nmbclusters) has to be a power
>of 2, so you should set it to 131072
>
>MorEl
>
>----- Original Message ----- 
>From: "Karim Fodil-Lemelin" <kfl at xiphos.ca>
>To: <freebsd-net at freebsd.org>
>Sent: Wednesday, June 15, 2005 6:08 PM
>Subject: (panic) Lots of network memory needed
>
>
>  
>
>>Hello,
>>
>>From kernel tuning page
>>    
>>
>(http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/configtuning-kern
>el-limits.html)
>  
>
>>Some sentence about nmbclusters says:
>>
>>"Under no circumstances should you specify an arbitrarily high value for
>>    
>>
>this parameter as it could lead to a boot time crash."
>  
>
>>Now I want to push the limits where I need 4KB buffer for each of the
>>    
>>
>32000 connections I want this server to handle. If I do the math:
>  
>
>>(32000 (conns) * 4 (KB/buffer) * 2 (buffer/conn)) / 2048 (KB/cluster)
>>
>>= 128000 clusters
>>
>>So I set this arbitrary high value in loader.conf under
>>    
>>
>(kern.ipc.nmbclusters) and no surprises I get panic: pmap_enter invalid page
>directory pdir=0x3cb063, va=0xfff800
>  
>
>>(va has a weird address here)
>>
>>I know I am pushing the limits here but I have plenty of memory (2GB) on
>>    
>>
>this system (after all its just 250MB for network memory ;) and this is
>mainly just experimentation.
>  
>
>>I would like some pointers toward fixing this. Is there another variable
>>    
>>
>tied into this (I guess so)? Could anybody points me to a technical document
>that would explain the relationship with that (those) other(s) presumed
>variable(s)?
>  
>
>>Thank you,
>>
>>
>>Karim
>>
>>
>>_______________________________________________
>>freebsd-net at freebsd.org mailing list
>>http://lists.freebsd.org/mailman/listinfo/freebsd-net
>>To unsubscribe, send any mail to "freebsd-net-unsubscribe at freebsd.org"
>>    
>>
>
>
>
>  
>

-- 
Karim Fodil-Lemelin
Lead Programmer

Xiphos Technologies Inc.
(514) 848-9640 x223
(514) 848-9644 fax
www.xiplink.com

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