Messages in this thread | | | Subject | Re: [PATCH 3/4] dma-debug: Dynamically expand the dma_debug_entry pool | From | John Garry <> | Date | Tue, 4 Dec 2018 17:38:12 +0000 |
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> >>> In fact, having got this far in, what I'd quite like to do is to get rid >>> of dma_debug_resize_entries() such that we never need to free things at >>> all, since then we could allocate whole pages as blocks of entries to >>> save on masses of individual slab allocations. >>> >> >> On a related topic, is it possible for the user to learn the total >> entries created at a given point in time? If not, could we add a file >> in the debugfs folder for this? >
Hi Robin,
> I did get as far as pondering that you effectively lose track of > utilisation once the low-water-mark of min_free_entries hits 0 and stays
I did try your patches and I noticed this, i.e I was hitting the point at which we start to alloc more entries.
> there - AFAICS it should be sufficient to just expose nr_total_entries > as-is, since users can then calculate current and maximum occupancy > based on *_free_entries. Does that sound reasonable to you? >
Sounds ok. I am just interested to know roughly how many DMA buffers we're using in our system.
> That also indirectly reminds me that this lot is documented in > DMA_API.txt, so I should be good and update that too...
Thanks, John
> > Cheers, > Robin. > > . >
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