Hi Jerin,
On Thu, Oct 31, 2019 at 01:49:10PM +0530, Jerin Jacob wrote:
> On Thu, Oct 31, 2019 at 12:25 PM Vamsi Krishna Attunuru
> <vattun...@marvell.com> wrote:
> >
> > Hi Olivier,
> >
> > Thanks for reworked patches.
> > With V2, Tests with 512MB & 2M page sizes work fine with octeontx2 mempool
> > pmd. One more concern is, octeontx fpa mempool driver also has the similar
> > requirements. How do we address that, Can you suggest the best way to avoid
> > code duplication in PMDs.
>
> # Actually both drivers don't call any HW specific function on those ops
> # Is it possible to move the code under " /* derived from
> rte_mempool_op_calc_mem_size_default() */"
> to static function in the mempool lib
> ie.
> it will keep the generic rte_mempool_op_calc_mem_size_default() clean
> and we can introduce
> other variant of rte_mempool_op_calc_mem_size_default() for this
> specific requirement which inclues the static generic function.
>
> I don't think, it is a one-off requirement to have an object size
> aligned to object start address in all HW based mempool
> implementation.
>
> The reason for the HW scheme doing such a scheme is the following:
> # if object size aligned to object block size, when HW wants to
> enqueue() a packet back to pool,
> irrespective of the free pointer offset it can enqueue the mbuf
> address to mempool.
>
> Example:
> X - mbuf start address
> Y - the object block size
> X + n <- is the packet pointer to send the packet
>
> When submitting the packet o HW to send the packet, SW needs to only
> mention the X + n and
> when HW frees it, it can derive the X(mbuf pointer address) by the
> following arithmetic
> X = (X + n ) - ((X + n) MOD Y)
>
> Hi Olivier,
> It is not worth going back and forth on this code organization. You
> can decide on a scheme, We will follow that.
Thanks for the explanation.
Our mail crossed each others. Please see my answer to Vamsi.
>
>
> >
> > Regards
> > A Vamsi
> >
> > > -----Original Message-----
> > > From: Olivier Matz <olivier.m...@6wind.com>
> > > Sent: Wednesday, October 30, 2019 8:06 PM
> > > To: dev@dpdk.org
> > > Cc: Anatoly Burakov <anatoly.bura...@intel.com>; Andrew Rybchenko
> > > <arybche...@solarflare.com>; Ferruh Yigit <ferruh.yi...@linux.intel.com>;
> > > Giridharan, Ganesan <ggiridha...@rbbn.com>; Jerin Jacob Kollanukkaran
> > > <jer...@marvell.com>; Kiran Kumar Kokkilagadda <kirankum...@marvell.com>;
> > > Stephen Hemminger <sthem...@microsoft.com>; Thomas Monjalon
> > > <tho...@monjalon.net>; Vamsi Krishna Attunuru <vattun...@marvell.com>
> > > Subject: [EXT] [PATCH v2 5/6] mempool: prevent objects from being across
> > > pages
> > >
> > > External Email
> > >
> > > ----------------------------------------------------------------------
> > > When populating a mempool, ensure that objects are not located across
> > > several
> > > pages, except if user did not request iova contiguous objects.
> > >
> > > Signed-off-by: Vamsi Krishna Attunuru <vattun...@marvell.com>
> > > Signed-off-by: Olivier Matz <olivier.m...@6wind.com>
> > > ---
> > > drivers/mempool/octeontx2/Makefile | 3 +
> > > drivers/mempool/octeontx2/meson.build | 3 +
> > > drivers/mempool/octeontx2/otx2_mempool_ops.c | 119 ++++++++++++++++---
> > > lib/librte_mempool/rte_mempool.c | 23 ++--
> > > lib/librte_mempool/rte_mempool_ops_default.c | 32 ++++-
> > > 5 files changed, 147 insertions(+), 33 deletions(-)
> > >
> > > diff --git a/drivers/mempool/octeontx2/Makefile
> > > b/drivers/mempool/octeontx2/Makefile
> > > index 87cce22c6..d781cbfc6 100644
> > > --- a/drivers/mempool/octeontx2/Makefile
> > > +++ b/drivers/mempool/octeontx2/Makefile
> > > @@ -27,6 +27,9 @@ EXPORT_MAP := rte_mempool_octeontx2_version.map
> > >
> > > LIBABIVER := 1
> > >
> > > +# for rte_mempool_get_page_size
> > > +CFLAGS += -DALLOW_EXPERIMENTAL_API
> > > +
> > > #
> > > # all source are stored in SRCS-y
> > > #
> > > diff --git a/drivers/mempool/octeontx2/meson.build
> > > b/drivers/mempool/octeontx2/meson.build
> > > index 9fde40f0e..28f9634da 100644
> > > --- a/drivers/mempool/octeontx2/meson.build
> > > +++ b/drivers/mempool/octeontx2/meson.build
> > > @@ -21,3 +21,6 @@ foreach flag: extra_flags endforeach
> > >
> > > deps += ['eal', 'mbuf', 'kvargs', 'bus_pci', 'common_octeontx2',
> > > 'mempool']
> > > +
> > > +# for rte_mempool_get_page_size
> > > +allow_experimental_apis = true
> > > diff --git a/drivers/mempool/octeontx2/otx2_mempool_ops.c
> > > b/drivers/mempool/octeontx2/otx2_mempool_ops.c
> > > index d769575f4..47117aec6 100644
> > > --- a/drivers/mempool/octeontx2/otx2_mempool_ops.c
> > > +++ b/drivers/mempool/octeontx2/otx2_mempool_ops.c
> > > @@ -713,12 +713,76 @@ static ssize_t
> > > otx2_npa_calc_mem_size(const struct rte_mempool *mp, uint32_t obj_num,
> > > uint32_t pg_shift, size_t *min_chunk_size, size_t
> > > *align) {
> > > - /*
> > > - * Simply need space for one more object to be able to
> > > - * fulfill alignment requirements.
> > > - */
> > > - return rte_mempool_op_calc_mem_size_default(mp, obj_num + 1,
> > > pg_shift,
> > > - min_chunk_size, align);
> > > + size_t total_elt_sz;
> > > + size_t obj_per_page, pg_sz, objs_in_last_page;
> > > + size_t mem_size;
> > > +
> > > + /* derived from rte_mempool_op_calc_mem_size_default() */
> > > +
> > > + total_elt_sz = mp->header_size + mp->elt_size + mp->trailer_size;
> > > +
> > > + if (total_elt_sz == 0) {
> > > + mem_size = 0;
> > > + } else if (pg_shift == 0) {
> > > + /* one object margin to fix alignment */
> > > + mem_size = total_elt_sz * (obj_num + 1);
> > > + } else {
> > > + pg_sz = (size_t)1 << pg_shift;
> > > + obj_per_page = pg_sz / total_elt_sz;
> > > +
> > > + /* we need to keep one object to fix alignment */
> > > + if (obj_per_page > 0)
> > > + obj_per_page--;
> > > +
> > > + if (obj_per_page == 0) {
> > > + /*
> > > + * Note that if object size is bigger than page
> > > size,
> > > + * then it is assumed that pages are grouped in
> > > subsets
> > > + * of physically continuous pages big enough to
> > > store
> > > + * at least one object.
> > > + */
> > > + mem_size = RTE_ALIGN_CEIL(2 * total_elt_sz,
> > > + pg_sz) * obj_num;
> > > + } else {
> > > + /* In the best case, the allocator will return a
> > > + * page-aligned address. For example, with 5 objs,
> > > + * the required space is as below:
> > > + * | page0 | page1 | page2 (last)
> > > |
> > > + * |obj0 |obj1 |xxx|obj2 |obj3 |xxx|obj4|
> > > + * <------------- mem_size ------------->
> > > + */
> > > + objs_in_last_page = ((obj_num - 1) % obj_per_page) +
> > > 1;
> > > + /* room required for the last page */
> > > + mem_size = objs_in_last_page * total_elt_sz;
> > > + /* room required for other pages */
> > > + mem_size += ((obj_num - objs_in_last_page) /
> > > + obj_per_page) << pg_shift;
> > > +
> > > + /* In the worst case, the allocator returns a
> > > + * non-aligned pointer, wasting up to
> > > + * total_elt_sz. Add a margin for that.
> > > + */
> > > + mem_size += total_elt_sz - 1;
> > > + }
> > > + }
> > > +
> > > + *min_chunk_size = total_elt_sz * 2;
> > > + *align = RTE_CACHE_LINE_SIZE;
> > > +
> > > + return mem_size;
> > > +}
> > > +
> > > +/* Returns -1 if object crosses a page boundary, else returns 0 */
> > > +static int check_obj_bounds(char *obj, size_t pg_sz, size_t elt_sz) {
> > > + if (pg_sz == 0)
> > > + return 0;
> > > + if (elt_sz > pg_sz)
> > > + return 0;
> > > + if (RTE_PTR_ALIGN(obj, pg_sz) != RTE_PTR_ALIGN(obj + elt_sz - 1,
> > > pg_sz))
> > > + return -1;
> > > + return 0;
> > > }
> > >
> > > static int
> > > @@ -726,8 +790,12 @@ otx2_npa_populate(struct rte_mempool *mp,
> > > unsigned int max_objs, void *vaddr,
> > > rte_iova_t iova, size_t len,
> > > rte_mempool_populate_obj_cb_t *obj_cb, void *obj_cb_arg)
> > > {
> > > - size_t total_elt_sz;
> > > + char *va = vaddr;
> > > + size_t total_elt_sz, pg_sz;
> > > size_t off;
> > > + unsigned int i;
> > > + void *obj;
> > > + int ret;
> > >
> > > if (iova == RTE_BAD_IOVA)
> > > return -EINVAL;
> > > @@ -735,22 +803,45 @@ otx2_npa_populate(struct rte_mempool *mp,
> > > unsigned int max_objs, void *vaddr,
> > > total_elt_sz = mp->header_size + mp->elt_size + mp->trailer_size;
> > >
> > > /* Align object start address to a multiple of total_elt_sz */
> > > - off = total_elt_sz - ((uintptr_t)vaddr % total_elt_sz);
> > > + off = total_elt_sz - (((uintptr_t)(va - 1) % total_elt_sz) + 1);
> > >
> > > if (len < off)
> > > return -EINVAL;
> > >
> > > - vaddr = (char *)vaddr + off;
> > > - iova += off;
> > > - len -= off;
> > >
> > > - npa_lf_aura_op_range_set(mp->pool_id, iova, iova + len);
> > > + npa_lf_aura_op_range_set(mp->pool_id, iova + off, iova + len - off);
> > >
> > > if (npa_lf_aura_range_update_check(mp->pool_id) < 0)
> > > return -EBUSY;
> > >
> > > - return rte_mempool_op_populate_default(mp, max_objs, vaddr, iova,
> > > len,
> > > - obj_cb, obj_cb_arg);
> > > + /* the following is derived from rte_mempool_op_populate_default()
> > > */
> > > +
> > > + ret = rte_mempool_get_page_size(mp, &pg_sz);
> > > + if (ret < 0)
> > > + return ret;
> > > +
> > > + for (i = 0; i < max_objs; i++) {
> > > + /* avoid objects to cross page boundaries, and align
> > > + * offset to a multiple of total_elt_sz.
> > > + */
> > > + if (check_obj_bounds(va + off, pg_sz, total_elt_sz) < 0) {
> > > + off += RTE_PTR_ALIGN_CEIL(va + off, pg_sz) - (va +
> > > off);
> > > + off += total_elt_sz - (((uintptr_t)(va + off - 1) %
> > > + total_elt_sz) + 1);
> > > + }
> > > +
> > > + if (off + total_elt_sz > len)
> > > + break;
> > > +
> > > + off += mp->header_size;
> > > + obj = va + off;
> > > + obj_cb(mp, obj_cb_arg, obj,
> > > + (iova == RTE_BAD_IOVA) ? RTE_BAD_IOVA : (iova +
> > > off));
> > > + rte_mempool_ops_enqueue_bulk(mp, &obj, 1);
> > > + off += mp->elt_size + mp->trailer_size;
> > > + }
> > > +
> > > + return i;
> > > }
> > >
> > > static struct rte_mempool_ops otx2_npa_ops = { diff --git
> > > a/lib/librte_mempool/rte_mempool.c b/lib/librte_mempool/rte_mempool.c
> > > index 758c5410b..d3db9273d 100644
> > > --- a/lib/librte_mempool/rte_mempool.c
> > > +++ b/lib/librte_mempool/rte_mempool.c
> > > @@ -431,8 +431,6 @@ rte_mempool_get_page_size(struct rte_mempool *mp,
> > > size_t *pg_sz)
> > >
> > > if (!need_iova_contig_obj)
> > > *pg_sz = 0;
> > > - else if (!alloc_in_ext_mem && rte_eal_iova_mode() == RTE_IOVA_VA)
> > > - *pg_sz = 0;
> > > else if (rte_eal_has_hugepages() || alloc_in_ext_mem)
> > > *pg_sz = get_min_page_size(mp->socket_id);
> > > else
> > > @@ -481,17 +479,15 @@ rte_mempool_populate_default(struct rte_mempool
> > > *mp)
> > > * then just set page shift and page size to 0, because the user has
> > > * indicated that there's no need to care about anything.
> > > *
> > > - * if we do need contiguous objects, there is also an option to
> > > reserve
> > > - * the entire mempool memory as one contiguous block of memory, in
> > > - * which case the page shift and alignment wouldn't matter as well.
> > > + * if we do need contiguous objects (if a mempool driver has its
> > > + * own calc_size() method returning min_chunk_size = mem_size),
> > > + * there is also an option to reserve the entire mempool memory
> > > + * as one contiguous block of memory.
> > > *
> > > * if we require contiguous objects, but not necessarily the entire
> > > - * mempool reserved space to be contiguous, then there are two
> > > options.
> > > - *
> > > - * if our IO addresses are virtual, not actual physical (IOVA as VA
> > > - * case), then no page shift needed - our memory allocation will
> > > give us
> > > - * contiguous IO memory as far as the hardware is concerned, so
> > > - * act as if we're getting contiguous memory.
> > > + * mempool reserved space to be contiguous, pg_sz will be != 0,
> > > + * and the default ops->populate() will take care of not placing
> > > + * objects across pages.
> > > *
> > > * if our IO addresses are physical, we may get memory from bigger
> > > * pages, or we might get memory from smaller pages, and how much
> > > of it @@ -504,11 +500,6 @@ rte_mempool_populate_default(struct
> > > rte_mempool *mp)
> > > *
> > > * If we fail to get enough contiguous memory, then we'll go and
> > > * reserve space in smaller chunks.
> > > - *
> > > - * We also have to take into account the fact that memory that we're
> > > - * going to allocate from can belong to an externally allocated
> > > memory
> > > - * area, in which case the assumption of IOVA as VA mode being
> > > - * synonymous with IOVA contiguousness will not hold.
> > > */
> > >
> > > need_iova_contig_obj = !(mp->flags &
> > > MEMPOOL_F_NO_IOVA_CONTIG); diff --git
> > > a/lib/librte_mempool/rte_mempool_ops_default.c
> > > b/lib/librte_mempool/rte_mempool_ops_default.c
> > > index f6aea7662..e5cd4600f 100644
> > > --- a/lib/librte_mempool/rte_mempool_ops_default.c
> > > +++ b/lib/librte_mempool/rte_mempool_ops_default.c
> > > @@ -61,21 +61,47 @@ rte_mempool_op_calc_mem_size_default(const struct
> > > rte_mempool *mp,
> > > return mem_size;
> > > }
> > >
> > > +/* Returns -1 if object crosses a page boundary, else returns 0 */
> > > +static int check_obj_bounds(char *obj, size_t pg_sz, size_t elt_sz) {
> > > + if (pg_sz == 0)
> > > + return 0;
> > > + if (elt_sz > pg_sz)
> > > + return 0;
> > > + if (RTE_PTR_ALIGN(obj, pg_sz) != RTE_PTR_ALIGN(obj + elt_sz - 1,
> > > pg_sz))
> > > + return -1;
> > > + return 0;
> > > +}
> > > +
> > > int
> > > rte_mempool_op_populate_default(struct rte_mempool *mp, unsigned int
> > > max_objs,
> > > void *vaddr, rte_iova_t iova, size_t len,
> > > rte_mempool_populate_obj_cb_t *obj_cb, void *obj_cb_arg) {
> > > - size_t total_elt_sz;
> > > + char *va = vaddr;
> > > + size_t total_elt_sz, pg_sz;
> > > size_t off;
> > > unsigned int i;
> > > void *obj;
> > > + int ret;
> > > +
> > > + ret = rte_mempool_get_page_size(mp, &pg_sz);
> > > + if (ret < 0)
> > > + return ret;
> > >
> > > total_elt_sz = mp->header_size + mp->elt_size + mp->trailer_size;
> > >
> > > - for (off = 0, i = 0; off + total_elt_sz <= len && i < max_objs;
> > > i++) {
> > > + for (off = 0, i = 0; i < max_objs; i++) {
> > > + /* avoid objects to cross page boundaries */
> > > + if (check_obj_bounds(va + off, pg_sz, total_elt_sz) < 0)
> > > + off += RTE_PTR_ALIGN_CEIL(va + off, pg_sz) - (va +
> > > off);
> > > +
> > > + if (off + total_elt_sz > len)
> > > + break;
> > > +
> > > off += mp->header_size;
> > > - obj = (char *)vaddr + off;
> > > + obj = va + off;
> > > obj_cb(mp, obj_cb_arg, obj,
> > > (iova == RTE_BAD_IOVA) ? RTE_BAD_IOVA : (iova +
> > > off));
> > > rte_mempool_ops_enqueue_bulk(mp, &obj, 1);
> > > --
> > > 2.20.1
> >
