Re: panic on kldload

["Simon 'corecode' Schubert" <corecode@xxxxxxxxxxxx>]

Matthew Dillon wrote:
> :hey,
> :
> :I just booted with hw.physmem=64m and got a panic when trying to load a module:
> :
> :panic: kld: malloc limit exceeded
> :
> :#3  0xc0182129 in kmalloc (size=78, type=0xc02f5600, flags=2)
> :    at /usr/build/src/sys/kern/kern_slaballoc.c:445
> :#4  0xc01678b4 in linker_make_file (pathname=0xc641b000 "./nvidia.ko", priv=0xc63ea028, 
> :    ops=0xc02f5bc8) at /usr/build/src/sys/kern/kern_linker.c:369
> :...
> :
> :the problem seems to be that M_LINKER already used 10% of all memory (allegedly).  In this case kmalloc() simply panics if passing M_WAITOK without M_NULLOK.  This is quite unfortunate.  Shouldn't we try to stay alive and print a warning and block, hoping that the problem will resolve itself?
> :
> :cheers
> :  simon
>
>     That's an administrative limit, it sounds like the solution is to simply
>     assign a reasonable minimum to it.
>
>     Well, what's the malloc limit when you have 64MB of ram?  From gdb
>     do 'print M_LINKER'.  And... is the amount of memory it thinks it is
>     using roughly similar to the amount of memory the loaded modules ought
>     to be taking up?

The limit is ~6MB, the linker consumes 8MB.  I just realized that we 
have in struct malloc_type:

        __uint16_t ks_limblocks; /* number of times blocked for hitting 
limit */

But we're never using this.

cheers
  simon