svn commit: r243631 - in head/sys: kern sys

[Alfred Perlstein]

On 1/12/13 11:56 AM, Adrian Chadd wrote:
> Hi,
>
> I think this outlines a larger scale problem here, which is that way,
> way too many things are relying on maxfiles here and it wasn't
> properly reviewed or thought out before it made it into the tree.
>
> So, can we either:
>
> * review _all_ the places maxfiles is being used, and finally fix those;
> * .. or revert this work until said review and fixup is done?
>
> This is the kind of thing that we should just not mess up at this point..

I'm not sure if regressing to the waterfall method of development is a 
good idea at this point.

I see a light at the end of the tunnel and we to continue to just handle 
these minor corner cases as we progress.

If we move to a model where a minor bug is grounds to completely remove 
helpful code then nothing will ever get done.

-Alfred

> Thanks,
>
>
>
> Adrian
>
> On 12 January 2013 07:46, Jayachandran C. <jchandra at freebsd.org> wrote:
>> On Fri, Jan 11, 2013 at 11:16 PM, Alan Cox <alc at rice.edu> wrote:
>>> On 01/11/2013 05:38, Jayachandran C. wrote:
>> [...]
>>>> I see an issue with commit on MIPS XLP platform as well.
>>>>
>>>> With 16 GB physical memory, the ncallout is calculated to be 538881
>>>> (since it is based on maxfiles - which is now based on the physical
>>>> memory). Due to this, the callwheel allocation per cpu is 16MB
>>>> (callwheelsize is 1MB). And on a 32 CPU machine, the total allocation
>>>> for callouts comes to 32*16MB = 512MB.
>>>>
>>>> I have worked around this issue for now by increasing VM_KMEM_SIZE_MAX
>>>> (which is 200MB now) - but I think a better fix is needed for this.
>>>>
>>> MIPS should use a definition for VM_KMEM_SIZE_MAX that scales with the
>>> kernel address space size, like amd64, i386, and sparc64, and not a
>>> fixed number.  I think that the following should work for both 32- and
>>> 64-bit processors:
>>>
>>> Index: mips/include/vmparam.h
>>> ===================================================================
>>> --- mips/include/vmparam.h      (revision 245229)
>>> +++ mips/include/vmparam.h      (working copy)
>>> @@ -130,10 +130,11 @@
>>>   #endif
>>>
>>>   /*
>>> - * Ceiling on amount of kmem_map kva space.
>>> + * Ceiling on the amount of kmem_map KVA space: 40% of the entire KVA
>>> space.
>>>    */
>>>   #ifndef VM_KMEM_SIZE_MAX
>>> -#define        VM_KMEM_SIZE_MAX        (200 * 1024 * 1024)
>>> +#define        VM_KMEM_SIZE_MAX        ((VM_MAX_KERNEL_ADDRESS - \
>>> +    VM_MIN_KERNEL_ADDRESS + 1) * 2 / 5)
>>>   #endif
>>>
>>>   /* initial pagein size of beginning of executable file */
>> This fix is needed, can you please check it in? I have tested it for
>> 32 and 64 bit.
>>
>> But the second part of the problem - allocating 512MB out of 16GB at
>> boot-time for callouts - might need a fix as well.
>>
>> Thanks,
>> JC.