Re: ReiserFS v3 choking when free space falls below 10%?

[Hans Reiser]

Jan Kara wrote:

>>Jan Kara wrote:
>>
>>    
>>
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>>>>Jan Kara wrote:
>>>>   
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>>>>        
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>>>>> Hi,
>>>>>
>>>>> just one note: I've looked to the in scan_bitmap() in bitmap.c. There is:
>>>>>       /* When the bitmap is more than 10% free, anyone can allocate.
>>>>>        * When it's less than 10% free, only files that already use the
>>>>>        * bitmap are allowed. Once we pass 80% full, this restriction
>>>>>        * is lifted.
>>>>>        *
>>>>>        * We do this so that files that grow later still have space
>>>>>        * close to
>>>>>        * their original allocation. This improves locality, and
>>>>>        * presumably
>>>>>        * performance as a result.
>>>>>        *
>>>>>        * This is only an allocation policy and does not make up for
>>>>>        * getting a
>>>>>        * bad hint. Decent hinting must be implemented for this to work
>>>>>        * well.
>>>>>        */
>>>>>       if (TEST_OPTION(skip_busy, s)
>>>>>           && SB_FREE_BLOCKS(s) > SB_BLOCK_COUNT(s) / 20) {
>>>>>     
>>>>>
>>>>>          
>>>>>
>>How about eliminating this feature entirely.   It seems rather dubious.
>>    
>>
>  Yes, but it may help reducing fragmentation as it leaves some free
>space in bitmaps for the files already ending in that bitmaps. I'm not
>sure if it really helps through...
>  
>
I think I was wrong, and retract my remark.