Re: [PATCH -v2] ext4: Use inode preallocation with -o noextents

[Eric Sandeen <sandeen@redhat.com>]

Andreas Dilger wrote:
> On Jun 11, 2008  11:26 +0800, Shen Feng wrote:
>> Andreas Dilger Wrote:
>>> On Jun 05, 2008  07:55 -0700, Mingming Cao wrote:
>>>>>  /**
>>>>> - * ext4_new_blocks_old() -- core block(s) allocation function
>>>>> + * ext4_orlov_new_blocks() -- core block(s) allocation function
>>>> what is orlov means? this is core function for non extent based without
>>>> mballoc block allocation, right? 
>>> Orlov is the name of the INODE allocator, not the block allocator.  I'm
>>> not sure there is a name for the block allocator except "old" or "bitmap".
>>> In the future I suspect we won't want to keep this version at all, using
>>> the mballoc allocator even for block-mapped files, but it is useful for
>>> now for performance comparisons.
>>>
>> Is that true?
>>
>> I got the following from the kernel ext4 documentation.
>> orlov		(*)	This enables the new Orlov block allocator. It is
>> 			enabled by default.
>>
>> oldalloc		This disables the Orlov block allocator and enables
>> 			the old block allocator.  Orlov should have better
>> 			performance - we'd like to get some feedback if it's
>> 			the contrary for you.
> 
> The documentation is incorrect then.  The Orlov allocator is for inodes:

Interestingly, though, the internets are full of references to "the
orlov block allocator for ext*" anyway.  :)  (it seems that the original
patches all referred to it this way):

http://lwn.net/Articles/14447/

Plus, some Orlov history for those interested ;)

http://web.archive.org/web/20070609035919/http://www.ptci.ru/gluk/dirpref/old/dirpref.html

-Eric