(no top posting please) On 02/12/15 00:26, Marcin Wojtas wrote: > Hi Florian, > > Can you please describe in more details, what would you expect from > such special abstraction layer regarding buffer managers? I'd like to > understand more of your expectations and evaluate possible work.
Well, something along these lines: - have the ability to register a particular pool (location + number of buffers) in a way that is relatively device agnostic (initialization would of course be device specific) - provide a set of buffer management APIs like those you proposed below, and have some generic code that leverages what drivers/net/ethernet/sun/niu.c does for instance - introduce a netdev_alloc_skb_from_pool() or something like that which would limit the amount of code to change in your network driver to benefit from that feature so based I am sure David would be able to suggest more detailed API. > > Best regards, > Marcin > > 2015-11-30 17:25 GMT+01:00 David Miller <da...@redhat.com>: >> From: Marcin Wojtas <m...@semihalf.com> >> Date: Mon, 30 Nov 2015 15:13:22 +0100 >> >>> What kind of abstraction and helpers do you mean? Some kind of API >>> (e.g. bm_alloc_buffer, bm_initialize_ring bm_put_buffer, >>> bm_get_buffer), which would be used by platform drivers (and specific >>> aplications if one wants to develop on top of the kernel)? >>> >>> In general, what is your top-view of such solution and its cooperation >>> with the drivers? >> >> The tricky parts involved have to do with allocating pages for the >> buffer pools and minimizing the number of atomic refcounting >> operations on those pages for for the puts and gets, particularly >> around buffer replenish runs. >> >> For example, if you're allocating a page for a buffer pool the device >> will chop into N (for any N < PAGE_SIZE) byte pieces, you can >> eliminate many atomic operations. -- Florian -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
