Hi, On Tue, Jul 16, 2019 at 09:40:59AM +0000, Vamsi Krishna Attunuru wrote: > > > > -----Original Message----- > > From: Olivier Matz <olivier.m...@6wind.com> > > Sent: Tuesday, July 16, 2019 2:17 PM > > To: Burakov, Anatoly <anatoly.bura...@intel.com> > > Cc: Jerin Jacob Kollanukkaran <jer...@marvell.com>; Ferruh Yigit > > <ferruh.yi...@intel.com>; Vamsi Krishna Attunuru <vattun...@marvell.com>; > > dev@dpdk.org; arybche...@solarflare.com > > Subject: Re: [dpdk-dev] [EXT] Re: [PATCH v6 0/4] add IOVA = VA support in > > KNI > > > > Hi, > > > > On Mon, Jul 15, 2019 at 10:38:53AM +0100, Burakov, Anatoly wrote: > > > On 15-Jul-19 5:54 AM, Jerin Jacob Kollanukkaran wrote: > > > > > > > > > > (also, i don't really like the name NO_PAGE_BOUND since > > > > > > > > > > in memzone API there's a "bounded memzone" allocation > > > > > > > > > > API, and this flag's name reads like objects would not > > > > > > > > > > be bounded by page size, not that they won't cross page > > > > > > > > > > boundary) > > > > > > > > > > > > > > > > > > No strong opinion for the name. What name you suggest? > > > > > > > > > > > > > > > > How about something like MEMPOOL_F_NO_PAGE_SPLIT? > > > > > > > > > > > > > > Looks good to me. > > > > > > > > > > > > > > In summary, Change wrt existing patch" > > > > > > > - Change NO_PAGE_BOUND to MEMPOOL_F_NO_PAGE_SPLIT > > > > > > > - Set this flag in rte_pktmbuf_pool_create () when > > > > > > rte_eal_has_hugepages() || > > > > > > > rte_malloc_heap_socket_is_external(socket_id)) > > > > > > > > > > > > If we are to have a special KNI allocation API, would we even need > > > > > > that? > > > > > > > > > > Not need this change in rte_pktmbuf_pool_create () if we introduce > > > > > a new rte_kni_pktmbuf_pool_create () API. > > > > > > > > Ferruh, Olivier, Anatoly, > > > > > > > > Any objection to create new rte_kni_pktmbuf_pool_create () API to > > > > embedded MEMPOOL_F_NO_PAGE_SPLIT flag requirement for KNI + IOVA > > as > > > > VA > > > > > > > > > > > > > > As long as we all are aware of what that means and agree with that > > > consequence (namely, separate codepaths for KNI and other PMD's) then > > > i have no specific objections. > > > > Sorry for the late feedback. > > > > I think we can change the default behavior of mempool populate(), to prevent > > objects from being accross 2 pages, except if the size of the object is > > bigger than > > the size of the page. This is already what is done in > > rte_mempool_op_calc_mem_size_default() when we want to estimate the > > amount of memory needed to allocate N objects. > > > > This would avoid the introduction of a specific API to allocate packets for > > kni, > > and a specific mempool flag. > > > > About the problem of 9K mbuf mentionned by Anatoly, could we imagine a > > check in kni code, that just returns an error "does not work with > > size(mbuf) > size(page)" ? > > > > Yes, change in default behavior avoids new APIs or flags. > Two minor changes on top of above suggestions. > 1) Can flag(NO_PAGE_SPLIT) be retained.?, sequence is like, flag is set by > default in rte_mempool_populate_default() > and later it can be cleared based on obj_per_page in > rte_mempool_op_calc_mem_size_default(). I do not see specific > requirement of these flag apart from handling above sequence.
Sorry, I don't get why you want to keep this flag. Is it to facilitate the error check in kni code? The flags are used by the mempool user to ask for a specific behavior, so if we change the default behavior, there is nothing to change to the user API. > 2) For problems of 9k mbuf, I think that check could be addressed in kni > lib(in rte_kni_init and return error). You can use rte_mempool_obj_iter() to iterate the objects (mbufs) in the mempool, to ensure that none of them is accross 2 pages.
