Re: Fw: two 2.6.13-rc3-mm3 oddities

[Manfred Spraul]

Dipankar Sarma wrote:

> Hugh, could you please try this with the experimental patch below ?
> Manfred, is it safe to decrement nr_files in file_free()
> instead of the destructor ? I can't see any problem.
>
>  
The ctor/dtor are only called when new objects are created, not on every 
kmem_cache_alloc/kmem_cache_free. Thus I would expect that the counter 
becomes negative on builds without CONFIG_DEBUG_SLAB.
Thus increase in the ctor and decrease in file_free() is the wrong 
thing. If you want to move the decrease from the dtor to file_free, then 
you must move the increase, too.
But: IIRC the counters were moved to the ctor/dtor for performance 
reasons, I'd guess mbligh ran into cache line trashing on the 
filp_count_lock spinlock with reaim or something like that.

--
   Manfred
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