On Fri, Oct 25, 2019 at 8:59 PM Xueming(Steven) Li <xuemi...@mellanox.com> wrote: > > > >From: Jerin Jacob <jerinjac...@gmail.com> > >Sent: Saturday, October 19, 2019 8:28 PM > > > >On Fri, 18 Oct, 2019, 3:40 pm Xueming(Steven) Li, > ><mailto:xuemi...@mellanox.com> wrote: > >> -----Original Message----- > >> From: Jerin Jacob <mailto:jerinjac...@gmail.com> > >> Sent: Friday, October 18, 2019 12:41 AM > >> To: Xueming(Steven) Li <mailto:xuemi...@mellanox.com> > >> Cc: Olivier Matz <mailto:olivier.m...@6wind.com>; Andrew Rybchenko > >> <mailto:arybche...@solarflare.com>; dpdk-dev <mailto:dev@dpdk.org>; Asaf > >> Penso > >> <mailto:as...@mellanox.com>; Ori Kam <mailto:or...@mellanox.com>; Stephen > >> Hemminger <mailto:step...@networkplumber.org> > >> Subject: Re: [dpdk-dev] [RFC] mempool: introduce indexed memory pool > >> > >> On Thu, Oct 17, 2019 at 6:43 PM Xueming(Steven) Li > >> <mailto:xuemi...@mellanox.com> wrote: > >> > > >> > > -----Original Message----- > >> > > From: Jerin Jacob <mailto:jerinjac...@gmail.com> > >> > > Sent: Thursday, October 17, 2019 3:14 PM > >> > > To: Xueming(Steven) Li <mailto:xuemi...@mellanox.com> > >> > > Cc: Olivier Matz <mailto:olivier.m...@6wind.com>; Andrew Rybchenko > >> > > <mailto:arybche...@solarflare.com>; dpdk-dev <mailto:dev@dpdk.org>; > >> > > Asaf Penso > >> > > <mailto:as...@mellanox.com>; Ori Kam <mailto:or...@mellanox.com> > >> > > Subject: Re: [dpdk-dev] [RFC] mempool: introduce indexed memory pool > >> > > > >> > > On Thu, Oct 17, 2019 at 12:25 PM Xueming Li > >> > > <mailto:xuemi...@mellanox.com> > >> wrote: > >> > > > > >> > > > Indexed memory pool manages memory entries by index, allocation > >> > > > from pool returns both memory pointer and index(ID). users save ID > >> > > > as u32 or less(u16) instead of traditional 8 bytes pointer. Memory > >> > > > could be retrieved from pool or returned to pool later by index. > >> > > > > >> > > > Pool allocates backend memory in chunk on demand, pool size grows > >> > > > dynamically. Bitmap is used to track entry usage in chunk, thus > >> > > > management overhead is one bit per entry. > >> > > > > >> > > > Standard rte_malloc demands malloc overhead(64B) and minimal data > >> > > > size(64B). This pool aims to such cost saving also pointer size. > >> > > > For scenario like creating millions of rte_flows each consists of > >> > > > small pieces of memories, the difference is huge. > >> > > > > >> > > > Like standard memory pool, this lightweight pool only support > >> > > > fixed size memory allocation. Pools should be created for each > >> > > > different size. > >> > > > > >> > > > To facilitate memory allocated by index, a set of ILIST_XXX macro > >> > > > defined to operate entries as regular LIST. > >> > > > > >> > > > By setting entry size to zero, pool can be used as ID generator. > >> > > > > >> > > > Signed-off-by: Xueming Li <mailto:xuemi...@mellanox.com> > >> > > > --- > >> > > > lib/librte_mempool/Makefile | 3 +- > >> > > > lib/librte_mempool/rte_indexed_pool.c | 289 > >> +++++++++++++++++++++ > >> > > > lib/librte_mempool/rte_indexed_pool.h | 224 ++++++++++++++++ > >> > > > >> > > Can this be abstracted over the driver interface instead of creating a > >> > > new > >> APIS? > >> > > ie using drivers/mempool/ > >> > > >> > The driver interface manage memory entries with pointers, while this api > >> uses u32 index as key... > >> > >> I see. As a use case, it makes sense to me. > > > >> Have you checked the possibility reusing/extending > >> lib/librte_eal/common/include/rte_bitmap.h for bitmap management, > >> instead of rolling a new one? > > > >Yes, the rte_bitmap designed for fixed bitmap size, to grow, have to copy > >almost entire bitmap(array1+array2). > >This pool distribute array2 into each trunk, and the trunk array actually > >plays the array1 role. > >When growing, just grow array1 which is smaller, no touch to existing array2 > >in each trunk. > > > >IMO, Growing bit map is generic problem so moving bitmap management logic to > >common place will be usefull for other libraries in future. My suggestion > >would be to enchanse rte_bitmap to support dynamic bitmap through new APIs. > > > Interesting that people always think this api a bitmap, now start to realize > it meaningful, memory just an optional attachment storage to each bit :) > I'll append missing api like set bitmap by index, then move it to eal common > folder, the header file should be rte_bitmap2.h?
+ cristian.dumitre...@intel.com(rte_bitmap.h maintainer) for any comments. rte_bitmap2.h may not be an intuitive name. One option could behave separate APIs for the new case in rte_bitmap.h. No strong opinions on the code organization in eal. > > > > > > >The map_xxx() naming might confused people, I'll make following change in > >next version: > > map_get()/map_set(): only used once and the code is simple, move > > code into caller. > > map_is_empty()/map_clear()/ : unused, remove > > map_clear_any(): relative simple, embed into caller. > >
