Re: [PATCH] 2.6.14 patch for supporting madvise(MADV_REMOVE)

[Badari Pulavarty <pbadari@us.ibm.com>]

Andrew Morton wrote:
> Badari Pulavarty <pbadari@us.ibm.com> wrote:
> 
>>>Why does madvise_remove() have an explicit check for swapper_space?
>>
>>I really don't remember (I yanked code from some other kernel routine
>>vmtruncate()).
> 
> 
> I don't see such a thing anywhere.  vmtruncate() has the IS_SWAPFILE()
> test, which I guess vmtruncate_range() ought to have too, for
> future-safety.

Yep. That was the check. Since I don't have inode and have mapping
handy anyway, check was made using that. I could change it, if you wish.

> 
> Logically, vmtruncate() should just be a special case of vmtruncate_range().
> But it's not - ugly, but hard to do anything about (need to implement
> ->truncate_range in all filesystems, but "know" which ones only support
> ->truncate_range() at eof).
> 
> 
>>>In your testing, how are you determining that the code is successfully
>>>removing the correct number of pages, from the correct file offset?
>>
>>I verified with test programs, added debug printk + looked through live
>>"crash" session + verified with UML testcases.
> 
> 
> OK, well please be sure to test it on 32-bit and 64-bit, operating in three
> ranges of the file: <2G, 2G-4G amd >4G.
> 
Will do.

Thanks,
Badari