[dpdk-dev] [PATCH v2] mbuf: support dynamic fields and flags
Olivier Matz
olivier.matz at 6wind.com
Thu Oct 24 09:56:26 CEST 2019
On Thu, Oct 24, 2019 at 07:38:15AM +0000, Slava Ovsiienko wrote:
> Hi,
>
> Doc building failed, it seems the rte_mbuf_dynfield_copy() description should be fixed:
>
> ./lib/librte_mbuf/rte_mbuf.h:1694: warning: argument 'm_dst' of command @param is not found in the argument list of rte_mbuf_dynfield_copy(struct rte_mbuf *mdst, const struct rte_mbuf *msrc)
> ./lib/librte_mbuf/rte_mbuf.h:1694: warning: argument 'm_src' of command @param is not found in the argument list of rte_mbuf_dynfield_copy(struct rte_mbuf *mdst, const struct rte_mbuf *msrc)
> ./lib/librte_mbuf/rte_mbuf.h:1694: warning: The following parameters of rte_mbuf_dynfield_copy(struct rte_mbuf *mdst, const struct rte_mbuf *msrc) are not documented
Thanks for spotting this, I'm adding the fix to the v3.
>
> With best regards,
> Slava
>
> > -----Original Message-----
> > From: dev <dev-bounces at dpdk.org> On Behalf Of Olivier Matz
> > Sent: Thursday, October 17, 2019 17:42
> > To: dev at dpdk.org
> > Cc: Andrew Rybchenko <arybchenko at solarflare.com>; Bruce Richardson
> > <bruce.richardson at intel.com>; Wang, Haiyue <haiyue.wang at intel.com>;
> > Jerin Jacob Kollanukkaran <jerinj at marvell.com>; Wiles, Keith
> > <keith.wiles at intel.com>; Ananyev, Konstantin
> > <konstantin.ananyev at intel.com>; Morten Brørup
> > <mb at smartsharesystems.com>; Stephen Hemminger
> > <stephen at networkplumber.org>; Thomas Monjalon
> > <thomas at monjalon.net>
> > Subject: [dpdk-dev] [PATCH v2] mbuf: support dynamic fields and flags
> >
> > Many features require to store data inside the mbuf. As the room in mbuf
> > structure is limited, it is not possible to have a field for each feature. Also,
> > changing fields in the mbuf structure can break the API or ABI.
> >
> > This commit addresses these issues, by enabling the dynamic registration of
> > fields or flags:
> >
> > - a dynamic field is a named area in the rte_mbuf structure, with a
> > given size (>= 1 byte) and alignment constraint.
> > - a dynamic flag is a named bit in the rte_mbuf structure.
> >
> > The typical use case is a PMD that registers space for an offload feature,
> > when the application requests to enable this feature. As the space in mbuf is
> > limited, the space should only be reserved if it is going to be used (i.e when
> > the application explicitly asks for it).
> >
> > The registration can be done at any moment, but it is not possible to
> > unregister fields or flags for now.
> >
> > Signed-off-by: Olivier Matz <olivier.matz at 6wind.com>
> > Acked-by: Thomas Monjalon <thomas at monjalon.net>
> > ---
> >
> > v2
> >
> > * Rebase on top of master: solve conflict with Stephen's patchset
> > (packet copy)
> > * Add new apis to register a dynamic field/flag at a specific place
> > * Add a dump function (sugg by David)
> > * Enhance field registration function to select the best offset, keeping
> > large aligned zones as much as possible (sugg by Konstantin)
> > * Use a size_t and unsigned int instead of int when relevant
> > (sugg by Konstantin)
> > * Use "uint64_t dynfield1[2]" in mbuf instead of 2 uint64_t fields
> > (sugg by Konstantin)
> > * Remove unused argument in private function (sugg by Konstantin)
> > * Fix and simplify locking (sugg by Konstantin)
> > * Fix minor typo
> >
> > rfc -> v1
> >
> > * Rebase on top of master
> > * Change registration API to use a structure instead of
> > variables, getting rid of #defines (Stephen's comment)
> > * Update flag registration to use a similar API as fields.
> > * Change max name length from 32 to 64 (sugg. by Thomas)
> > * Enhance API documentation (Haiyue's and Andrew's comments)
> > * Add a debug log at registration
> > * Add some words in release note
> > * Did some performance tests (sugg. by Andrew):
> > On my platform, reading a dynamic field takes ~3 cycles more
> > than a static field, and ~2 cycles more for writing.
> >
> > app/test/test_mbuf.c | 145 ++++++-
> > doc/guides/rel_notes/release_19_11.rst | 7 +
> > lib/librte_mbuf/Makefile | 2 +
> > lib/librte_mbuf/meson.build | 6 +-
> > lib/librte_mbuf/rte_mbuf.h | 23 +-
> > lib/librte_mbuf/rte_mbuf_dyn.c | 548 +++++++++++++++++++++++++
> > lib/librte_mbuf/rte_mbuf_dyn.h | 226 ++++++++++
> > lib/librte_mbuf/rte_mbuf_version.map | 7 +
> > 8 files changed, 959 insertions(+), 5 deletions(-) create mode 100644
> > lib/librte_mbuf/rte_mbuf_dyn.c create mode 100644
> > lib/librte_mbuf/rte_mbuf_dyn.h
> >
> > diff --git a/app/test/test_mbuf.c b/app/test/test_mbuf.c index
> > b9c2b2500..01cafad59 100644
> > --- a/app/test/test_mbuf.c
> > +++ b/app/test/test_mbuf.c
> > @@ -28,6 +28,7 @@
> > #include <rte_random.h>
> > #include <rte_cycles.h>
> > #include <rte_malloc.h>
> > +#include <rte_mbuf_dyn.h>
> >
> > #include "test.h"
> >
> > @@ -657,7 +658,6 @@ test_attach_from_different_pool(struct
> > rte_mempool *pktmbuf_pool,
> > rte_pktmbuf_free(clone2);
> > return -1;
> > }
> > -#undef GOTO_FAIL
> >
> > /*
> > * test allocation and free of mbufs
> > @@ -1276,6 +1276,143 @@ test_tx_offload(void)
> > return (v1 == v2) ? 0 : -EINVAL;
> > }
> >
> > +static int
> > +test_mbuf_dyn(struct rte_mempool *pktmbuf_pool) {
> > + const struct rte_mbuf_dynfield dynfield = {
> > + .name = "test-dynfield",
> > + .size = sizeof(uint8_t),
> > + .align = __alignof__(uint8_t),
> > + .flags = 0,
> > + };
> > + const struct rte_mbuf_dynfield dynfield2 = {
> > + .name = "test-dynfield2",
> > + .size = sizeof(uint16_t),
> > + .align = __alignof__(uint16_t),
> > + .flags = 0,
> > + };
> > + const struct rte_mbuf_dynfield dynfield3 = {
> > + .name = "test-dynfield3",
> > + .size = sizeof(uint8_t),
> > + .align = __alignof__(uint8_t),
> > + .flags = 0,
> > + };
> > + const struct rte_mbuf_dynfield dynfield_fail_big = {
> > + .name = "test-dynfield-fail-big",
> > + .size = 256,
> > + .align = 1,
> > + .flags = 0,
> > + };
> > + const struct rte_mbuf_dynfield dynfield_fail_align = {
> > + .name = "test-dynfield-fail-align",
> > + .size = 1,
> > + .align = 3,
> > + .flags = 0,
> > + };
> > + const struct rte_mbuf_dynflag dynflag = {
> > + .name = "test-dynflag",
> > + .flags = 0,
> > + };
> > + const struct rte_mbuf_dynflag dynflag2 = {
> > + .name = "test-dynflag2",
> > + .flags = 0,
> > + };
> > + const struct rte_mbuf_dynflag dynflag3 = {
> > + .name = "test-dynflag3",
> > + .flags = 0,
> > + };
> > + struct rte_mbuf *m = NULL;
> > + int offset, offset2, offset3;
> > + int flag, flag2, flag3;
> > + int ret;
> > +
> > + printf("Test mbuf dynamic fields and flags\n");
> > + rte_mbuf_dyn_dump(stdout);
> > +
> > + offset = rte_mbuf_dynfield_register(&dynfield);
> > + if (offset == -1)
> > + GOTO_FAIL("failed to register dynamic field, offset=%d: %s",
> > + offset, strerror(errno));
> > +
> > + ret = rte_mbuf_dynfield_register(&dynfield);
> > + if (ret != offset)
> > + GOTO_FAIL("failed to lookup dynamic field, ret=%d: %s",
> > + ret, strerror(errno));
> > +
> > + offset2 = rte_mbuf_dynfield_register(&dynfield2);
> > + if (offset2 == -1 || offset2 == offset || (offset2 & 1))
> > + GOTO_FAIL("failed to register dynamic field 2, offset2=%d:
> > %s",
> > + offset2, strerror(errno));
> > +
> > + offset3 = rte_mbuf_dynfield_register_offset(&dynfield3,
> > + offsetof(struct rte_mbuf, dynfield1[1]));
> > + if (offset3 != offsetof(struct rte_mbuf, dynfield1[1]))
> > + GOTO_FAIL("failed to register dynamic field 3, offset=%d:
> > %s",
> > + offset3, strerror(errno));
> > +
> > + printf("dynfield: offset=%d, offset2=%d, offset3=%d\n",
> > + offset, offset2, offset3);
> > +
> > + ret = rte_mbuf_dynfield_register(&dynfield_fail_big);
> > + if (ret != -1)
> > + GOTO_FAIL("dynamic field creation should fail (too big)");
> > +
> > + ret = rte_mbuf_dynfield_register(&dynfield_fail_align);
> > + if (ret != -1)
> > + GOTO_FAIL("dynamic field creation should fail (bad
> > alignment)");
> > +
> > + ret = rte_mbuf_dynfield_register_offset(&dynfield_fail_align,
> > + offsetof(struct rte_mbuf, ol_flags));
> > + if (ret != -1)
> > + GOTO_FAIL("dynamic field creation should fail (not avail)");
> > +
> > + flag = rte_mbuf_dynflag_register(&dynflag);
> > + if (flag == -1)
> > + GOTO_FAIL("failed to register dynamic flag, flag=%d: %s",
> > + flag, strerror(errno));
> > +
> > + ret = rte_mbuf_dynflag_register(&dynflag);
> > + if (ret != flag)
> > + GOTO_FAIL("failed to lookup dynamic flag, ret=%d: %s",
> > + ret, strerror(errno));
> > +
> > + flag2 = rte_mbuf_dynflag_register(&dynflag2);
> > + if (flag2 == -1 || flag2 == flag)
> > + GOTO_FAIL("failed to register dynamic flag 2, flag2=%d: %s",
> > + flag2, strerror(errno));
> > +
> > + flag3 = rte_mbuf_dynflag_register_bitnum(&dynflag3,
> > + rte_bsf64(PKT_LAST_FREE));
> > + if (flag3 != rte_bsf64(PKT_LAST_FREE))
> > + GOTO_FAIL("failed to register dynamic flag 3, flag2=%d: %s",
> > + flag3, strerror(errno));
> > +
> > + printf("dynflag: flag=%d, flag2=%d, flag3=%d\n", flag, flag2, flag3);
> > +
> > + /* set, get dynamic field */
> > + m = rte_pktmbuf_alloc(pktmbuf_pool);
> > + if (m == NULL)
> > + GOTO_FAIL("Cannot allocate mbuf");
> > +
> > + *RTE_MBUF_DYNFIELD(m, offset, uint8_t *) = 1;
> > + if (*RTE_MBUF_DYNFIELD(m, offset, uint8_t *) != 1)
> > + GOTO_FAIL("failed to read dynamic field");
> > + *RTE_MBUF_DYNFIELD(m, offset2, uint16_t *) = 1000;
> > + if (*RTE_MBUF_DYNFIELD(m, offset2, uint16_t *) != 1000)
> > + GOTO_FAIL("failed to read dynamic field");
> > +
> > + /* set a dynamic flag */
> > + m->ol_flags |= (1ULL << flag);
> > +
> > + rte_mbuf_dyn_dump(stdout);
> > + rte_pktmbuf_free(m);
> > + return 0;
> > +fail:
> > + rte_pktmbuf_free(m);
> > + return -1;
> > +}
> > +#undef GOTO_FAIL
> > +
> > static int
> > test_mbuf(void)
> > {
> > @@ -1295,6 +1432,12 @@ test_mbuf(void)
> > goto err;
> > }
> >
> > + /* test registration of dynamic fields and flags */
> > + if (test_mbuf_dyn(pktmbuf_pool) < 0) {
> > + printf("mbuf dynflag test failed\n");
> > + goto err;
> > + }
> > +
> > /* create a specific pktmbuf pool with a priv_size != 0 and no data
> > * room size */
> > pktmbuf_pool2 = rte_pktmbuf_pool_create("test_pktmbuf_pool2",
> > diff --git a/doc/guides/rel_notes/release_19_11.rst
> > b/doc/guides/rel_notes/release_19_11.rst
> > index 85953b962..9e9c94554 100644
> > --- a/doc/guides/rel_notes/release_19_11.rst
> > +++ b/doc/guides/rel_notes/release_19_11.rst
> > @@ -21,6 +21,13 @@ DPDK Release 19.11
> >
> > xdg-open build/doc/html/guides/rel_notes/release_19_11.html
> >
> > +* **Add support of support dynamic fields and flags in mbuf.**
> > +
> > + This new feature adds the ability to dynamically register some room
> > + for a field or a flag in the mbuf structure. This is typically used
> > + for specific offload features, where adding a static field or flag in
> > + the mbuf is not justified.
> > +
> >
> > New Features
> > ------------
> > diff --git a/lib/librte_mbuf/Makefile b/lib/librte_mbuf/Makefile index
> > c8f6d2689..5a9bcee73 100644
> > --- a/lib/librte_mbuf/Makefile
> > +++ b/lib/librte_mbuf/Makefile
> > @@ -17,8 +17,10 @@ LIBABIVER := 5
> >
> > # all source are stored in SRCS-y
> > SRCS-$(CONFIG_RTE_LIBRTE_MBUF) := rte_mbuf.c rte_mbuf_ptype.c
> > rte_mbuf_pool_ops.c
> > +SRCS-$(CONFIG_RTE_LIBRTE_MBUF) += rte_mbuf_dyn.c
> >
> > # install includes
> > SYMLINK-$(CONFIG_RTE_LIBRTE_MBUF)-include := rte_mbuf.h
> > rte_mbuf_ptype.h rte_mbuf_pool_ops.h
> > +SYMLINK-$(CONFIG_RTE_LIBRTE_MBUF)-include += rte_mbuf_dyn.h
> >
> > include $(RTE_SDK)/mk/rte.lib.mk
> > diff --git a/lib/librte_mbuf/meson.build b/lib/librte_mbuf/meson.build index
> > 6cc11ebb4..9137e8f26 100644
> > --- a/lib/librte_mbuf/meson.build
> > +++ b/lib/librte_mbuf/meson.build
> > @@ -2,8 +2,10 @@
> > # Copyright(c) 2017 Intel Corporation
> >
> > version = 5
> > -sources = files('rte_mbuf.c', 'rte_mbuf_ptype.c', 'rte_mbuf_pool_ops.c') -
> > headers = files('rte_mbuf.h', 'rte_mbuf_ptype.h', 'rte_mbuf_pool_ops.h')
> > +sources = files('rte_mbuf.c', 'rte_mbuf_ptype.c', 'rte_mbuf_pool_ops.c',
> > + 'rte_mbuf_dyn.c')
> > +headers = files('rte_mbuf.h', 'rte_mbuf_ptype.h', 'rte_mbuf_pool_ops.h',
> > + 'rte_mbuf_dyn.h')
> > deps += ['mempool']
> >
> > allow_experimental_apis = true
> > diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h index
> > fb0849ac1..5740b1e93 100644
> > --- a/lib/librte_mbuf/rte_mbuf.h
> > +++ b/lib/librte_mbuf/rte_mbuf.h
> > @@ -198,9 +198,12 @@ extern "C" {
> > #define PKT_RX_OUTER_L4_CKSUM_GOOD (1ULL << 22)
> > #define PKT_RX_OUTER_L4_CKSUM_INVALID ((1ULL << 21) | (1ULL << 22))
> >
> > -/* add new RX flags here */
> > +/* add new RX flags here, don't forget to update PKT_FIRST_FREE */
> >
> > -/* add new TX flags here */
> > +#define PKT_FIRST_FREE (1ULL << 23)
> > +#define PKT_LAST_FREE (1ULL << 39)
> > +
> > +/* add new TX flags here, don't forget to update PKT_LAST_FREE */
> >
> > /**
> > * Indicate that the metadata field in the mbuf is in use.
> > @@ -738,6 +741,7 @@ struct rte_mbuf {
> > */
> > struct rte_mbuf_ext_shared_info *shinfo;
> >
> > + uint64_t dynfield1[2]; /**< Reserved for dynamic fields. */
> > } __rte_cache_aligned;
> >
> > /**
> > @@ -1684,6 +1688,20 @@ rte_pktmbuf_attach_extbuf(struct rte_mbuf *m,
> > void *buf_addr,
> > */
> > #define rte_pktmbuf_detach_extbuf(m) rte_pktmbuf_detach(m)
> >
> > +/**
> > + * Copy dynamic fields from m_src to m_dst.
> > + *
> > + * @param m_dst
> > + * The destination mbuf.
> > + * @param m_src
> > + * The source mbuf.
> > + */
> > +static inline void
> > +rte_mbuf_dynfield_copy(struct rte_mbuf *mdst, const struct rte_mbuf
> > +*msrc) {
> > + memcpy(&mdst->dynfield1, msrc->dynfield1, sizeof(mdst-
> > >dynfield1)); }
> > +
> > /* internal */
> > static inline void
> > __rte_pktmbuf_copy_hdr(struct rte_mbuf *mdst, const struct rte_mbuf
> > *msrc) @@ -1695,6 +1713,7 @@ __rte_pktmbuf_copy_hdr(struct rte_mbuf
> > *mdst, const struct rte_mbuf *msrc)
> > mdst->hash = msrc->hash;
> > mdst->packet_type = msrc->packet_type;
> > mdst->timestamp = msrc->timestamp;
> > + rte_mbuf_dynfield_copy(mdst, msrc);
> > }
> >
> > /**
> > diff --git a/lib/librte_mbuf/rte_mbuf_dyn.c
> > b/lib/librte_mbuf/rte_mbuf_dyn.c new file mode 100644 index
> > 000000000..9ef235483
> > --- /dev/null
> > +++ b/lib/librte_mbuf/rte_mbuf_dyn.c
> > @@ -0,0 +1,548 @@
> > +/* SPDX-License-Identifier: BSD-3-Clause
> > + * Copyright 2019 6WIND S.A.
> > + */
> > +
> > +#include <sys/queue.h>
> > +#include <stdint.h>
> > +#include <limits.h>
> > +
> > +#include <rte_common.h>
> > +#include <rte_eal.h>
> > +#include <rte_eal_memconfig.h>
> > +#include <rte_tailq.h>
> > +#include <rte_errno.h>
> > +#include <rte_malloc.h>
> > +#include <rte_string_fns.h>
> > +#include <rte_mbuf.h>
> > +#include <rte_mbuf_dyn.h>
> > +
> > +#define RTE_MBUF_DYN_MZNAME "rte_mbuf_dyn"
> > +
> > +struct mbuf_dynfield_elt {
> > + TAILQ_ENTRY(mbuf_dynfield_elt) next;
> > + struct rte_mbuf_dynfield params;
> > + size_t offset;
> > +};
> > +TAILQ_HEAD(mbuf_dynfield_list, rte_tailq_entry);
> > +
> > +static struct rte_tailq_elem mbuf_dynfield_tailq = {
> > + .name = "RTE_MBUF_DYNFIELD",
> > +};
> > +EAL_REGISTER_TAILQ(mbuf_dynfield_tailq);
> > +
> > +struct mbuf_dynflag_elt {
> > + TAILQ_ENTRY(mbuf_dynflag_elt) next;
> > + struct rte_mbuf_dynflag params;
> > + unsigned int bitnum;
> > +};
> > +TAILQ_HEAD(mbuf_dynflag_list, rte_tailq_entry);
> > +
> > +static struct rte_tailq_elem mbuf_dynflag_tailq = {
> > + .name = "RTE_MBUF_DYNFLAG",
> > +};
> > +EAL_REGISTER_TAILQ(mbuf_dynflag_tailq);
> > +
> > +struct mbuf_dyn_shm {
> > + /**
> > + * For each mbuf byte, free_space[i] != 0 if space is free.
> > + * The value is the size of the biggest aligned element that
> > + * can fit in the zone.
> > + */
> > + uint8_t free_space[sizeof(struct rte_mbuf)];
> > + /** Bitfield of available flags. */
> > + uint64_t free_flags;
> > +};
> > +static struct mbuf_dyn_shm *shm;
> > +
> > +/* Set the value of free_space[] according to the size and alignment of
> > + * the free areas. This helps to select the best place when reserving a
> > + * dynamic field. Assume tailq is locked.
> > + */
> > +static void
> > +process_score(void)
> > +{
> > + size_t off, align, size, i;
> > +
> > + /* first, erase previous info */
> > + for (i = 0; i < sizeof(struct rte_mbuf); i++) {
> > + if (shm->free_space[i])
> > + shm->free_space[i] = 1;
> > + }
> > +
> > + for (off = 0; off < sizeof(struct rte_mbuf); off++) {
> > + /* get the size of the free zone */
> > + for (size = 0; shm->free_space[off + size]; size++)
> > + ;
> > + if (size == 0)
> > + continue;
> > +
> > + /* get the alignment of biggest object that can fit in
> > + * the zone at this offset.
> > + */
> > + for (align = 1;
> > + (off % (align << 1)) == 0 && (align << 1) <= size;
> > + align <<= 1)
> > + ;
> > +
> > + /* save it in free_space[] */
> > + for (i = off; i < off + size; i++)
> > + shm->free_space[i] = RTE_MAX(align, shm-
> > >free_space[i]);
> > + }
> > +}
> > +
> > +/* Allocate and initialize the shared memory. Assume tailq is locked */
> > +static int
> > +init_shared_mem(void)
> > +{
> > + const struct rte_memzone *mz;
> > + uint64_t mask;
> > +
> > + if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
> > + mz =
> > rte_memzone_reserve_aligned(RTE_MBUF_DYN_MZNAME,
> > + sizeof(struct
> > mbuf_dyn_shm),
> > + SOCKET_ID_ANY, 0,
> > + RTE_CACHE_LINE_SIZE);
> > + } else {
> > + mz = rte_memzone_lookup(RTE_MBUF_DYN_MZNAME);
> > + }
> > + if (mz == NULL)
> > + return -1;
> > +
> > + shm = mz->addr;
> > +
> > +#define mark_free(field) \
> > + memset(&shm->free_space[offsetof(struct rte_mbuf, field)], \
> > + 1, sizeof(((struct rte_mbuf *)0)->field))
> > +
> > + if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
> > + /* init free_space, keep it sync'd with
> > + * rte_mbuf_dynfield_copy().
> > + */
> > + memset(shm, 0, sizeof(*shm));
> > + mark_free(dynfield1);
> > +
> > + /* init free_flags */
> > + for (mask = PKT_FIRST_FREE; mask <= PKT_LAST_FREE; mask
> > <<= 1)
> > + shm->free_flags |= mask;
> > +
> > + process_score();
> > + }
> > +#undef mark_free
> > +
> > + return 0;
> > +}
> > +
> > +/* check if this offset can be used */
> > +static int
> > +check_offset(size_t offset, size_t size, size_t align) {
> > + size_t i;
> > +
> > + if ((offset & (align - 1)) != 0)
> > + return -1;
> > + if (offset + size > sizeof(struct rte_mbuf))
> > + return -1;
> > +
> > + for (i = 0; i < size; i++) {
> > + if (!shm->free_space[i + offset])
> > + return -1;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +/* assume tailq is locked */
> > +static struct mbuf_dynfield_elt *
> > +__mbuf_dynfield_lookup(const char *name) {
> > + struct mbuf_dynfield_list *mbuf_dynfield_list;
> > + struct mbuf_dynfield_elt *mbuf_dynfield;
> > + struct rte_tailq_entry *te;
> > +
> > + mbuf_dynfield_list = RTE_TAILQ_CAST(
> > + mbuf_dynfield_tailq.head, mbuf_dynfield_list);
> > +
> > + TAILQ_FOREACH(te, mbuf_dynfield_list, next) {
> > + mbuf_dynfield = (struct mbuf_dynfield_elt *)te->data;
> > + if (strcmp(name, mbuf_dynfield->params.name) == 0)
> > + break;
> > + }
> > +
> > + if (te == NULL) {
> > + rte_errno = ENOENT;
> > + return NULL;
> > + }
> > +
> > + return mbuf_dynfield;
> > +}
> > +
> > +int
> > +rte_mbuf_dynfield_lookup(const char *name, struct rte_mbuf_dynfield
> > +*params) {
> > + struct mbuf_dynfield_elt *mbuf_dynfield;
> > +
> > + if (shm == NULL) {
> > + rte_errno = ENOENT;
> > + return -1;
> > + }
> > +
> > + rte_mcfg_tailq_read_lock();
> > + mbuf_dynfield = __mbuf_dynfield_lookup(name);
> > + rte_mcfg_tailq_read_unlock();
> > +
> > + if (mbuf_dynfield == NULL) {
> > + rte_errno = ENOENT;
> > + return -1;
> > + }
> > +
> > + if (params != NULL)
> > + memcpy(params, &mbuf_dynfield->params,
> > sizeof(*params));
> > +
> > + return mbuf_dynfield->offset;
> > +}
> > +
> > +static int mbuf_dynfield_cmp(const struct rte_mbuf_dynfield *params1,
> > + const struct rte_mbuf_dynfield *params2) {
> > + if (strcmp(params1->name, params2->name))
> > + return -1;
> > + if (params1->size != params2->size)
> > + return -1;
> > + if (params1->align != params2->align)
> > + return -1;
> > + if (params1->flags != params2->flags)
> > + return -1;
> > + return 0;
> > +}
> > +
> > +/* assume tailq is locked */
> > +static int
> > +__rte_mbuf_dynfield_register_offset(const struct rte_mbuf_dynfield
> > *params,
> > + size_t req)
> > +{
> > + struct mbuf_dynfield_list *mbuf_dynfield_list;
> > + struct mbuf_dynfield_elt *mbuf_dynfield = NULL;
> > + struct rte_tailq_entry *te = NULL;
> > + unsigned int best_zone = UINT_MAX;
> > + size_t i, offset;
> > + int ret;
> > +
> > + if (shm == NULL && init_shared_mem() < 0)
> > + return -1;
> > +
> > + mbuf_dynfield = __mbuf_dynfield_lookup(params->name);
> > + if (mbuf_dynfield != NULL) {
> > + if (req != SIZE_MAX && req != mbuf_dynfield->offset) {
> > + rte_errno = EEXIST;
> > + return -1;
> > + }
> > + if (mbuf_dynfield_cmp(params, &mbuf_dynfield->params) <
> > 0) {
> > + rte_errno = EEXIST;
> > + return -1;
> > + }
> > + return mbuf_dynfield->offset;
> > + }
> > +
> > + if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
> > + rte_errno = EPERM;
> > + return -1;
> > + }
> > +
> > + if (req == SIZE_MAX) {
> > + for (offset = 0;
> > + offset < sizeof(struct rte_mbuf);
> > + offset++) {
> > + if (check_offset(offset, params->size,
> > + params->align) == 0 &&
> > + shm->free_space[offset] <
> > best_zone) {
> > + best_zone = shm->free_space[offset];
> > + req = offset;
> > + }
> > + }
> > + if (req == SIZE_MAX) {
> > + rte_errno = ENOENT;
> > + return -1;
> > + }
> > + } else {
> > + if (check_offset(req, params->size, params->align) < 0) {
> > + rte_errno = EBUSY;
> > + return -1;
> > + }
> > + }
> > +
> > + offset = req;
> > + mbuf_dynfield_list = RTE_TAILQ_CAST(
> > + mbuf_dynfield_tailq.head, mbuf_dynfield_list);
> > +
> > + te = rte_zmalloc("MBUF_DYNFIELD_TAILQ_ENTRY", sizeof(*te), 0);
> > + if (te == NULL)
> > + return -1;
> > +
> > + mbuf_dynfield = rte_zmalloc("mbuf_dynfield",
> > sizeof(*mbuf_dynfield), 0);
> > + if (mbuf_dynfield == NULL) {
> > + rte_free(te);
> > + return -1;
> > + }
> > +
> > + ret = strlcpy(mbuf_dynfield->params.name, params->name,
> > + sizeof(mbuf_dynfield->params.name));
> > + if (ret < 0 || ret >= (int)sizeof(mbuf_dynfield->params.name)) {
> > + rte_errno = ENAMETOOLONG;
> > + rte_free(mbuf_dynfield);
> > + rte_free(te);
> > + return -1;
> > + }
> > + memcpy(&mbuf_dynfield->params, params, sizeof(mbuf_dynfield-
> > >params));
> > + mbuf_dynfield->offset = offset;
> > + te->data = mbuf_dynfield;
> > +
> > + TAILQ_INSERT_TAIL(mbuf_dynfield_list, te, next);
> > +
> > + for (i = offset; i < offset + params->size; i++)
> > + shm->free_space[i] = 0;
> > + process_score();
> > +
> > + RTE_LOG(DEBUG, MBUF, "Registered dynamic field %s (sz=%zu,
> > al=%zu, fl=0x%x) -> %zd\n",
> > + params->name, params->size, params->align, params->flags,
> > + offset);
> > +
> > + return offset;
> > +}
> > +
> > +int
> > +rte_mbuf_dynfield_register_offset(const struct rte_mbuf_dynfield
> > *params,
> > + size_t req)
> > +{
> > + int ret;
> > +
> > + if (params->size >= sizeof(struct rte_mbuf)) {
> > + rte_errno = EINVAL;
> > + return -1;
> > + }
> > + if (!rte_is_power_of_2(params->align)) {
> > + rte_errno = EINVAL;
> > + return -1;
> > + }
> > + if (params->flags != 0) {
> > + rte_errno = EINVAL;
> > + return -1;
> > + }
> > +
> > + rte_mcfg_tailq_write_lock();
> > + ret = __rte_mbuf_dynfield_register_offset(params, req);
> > + rte_mcfg_tailq_write_unlock();
> > +
> > + return ret;
> > +}
> > +
> > +int
> > +rte_mbuf_dynfield_register(const struct rte_mbuf_dynfield *params) {
> > + return rte_mbuf_dynfield_register_offset(params, SIZE_MAX); }
> > +
> > +/* assume tailq is locked */
> > +static struct mbuf_dynflag_elt *
> > +__mbuf_dynflag_lookup(const char *name) {
> > + struct mbuf_dynflag_list *mbuf_dynflag_list;
> > + struct mbuf_dynflag_elt *mbuf_dynflag;
> > + struct rte_tailq_entry *te;
> > +
> > + mbuf_dynflag_list = RTE_TAILQ_CAST(
> > + mbuf_dynflag_tailq.head, mbuf_dynflag_list);
> > +
> > + TAILQ_FOREACH(te, mbuf_dynflag_list, next) {
> > + mbuf_dynflag = (struct mbuf_dynflag_elt *)te->data;
> > + if (strncmp(name, mbuf_dynflag->params.name,
> > + RTE_MBUF_DYN_NAMESIZE) == 0)
> > + break;
> > + }
> > +
> > + if (te == NULL) {
> > + rte_errno = ENOENT;
> > + return NULL;
> > + }
> > +
> > + return mbuf_dynflag;
> > +}
> > +
> > +int
> > +rte_mbuf_dynflag_lookup(const char *name,
> > + struct rte_mbuf_dynflag *params)
> > +{
> > + struct mbuf_dynflag_elt *mbuf_dynflag;
> > +
> > + if (shm == NULL) {
> > + rte_errno = ENOENT;
> > + return -1;
> > + }
> > +
> > + rte_mcfg_tailq_read_lock();
> > + mbuf_dynflag = __mbuf_dynflag_lookup(name);
> > + rte_mcfg_tailq_read_unlock();
> > +
> > + if (mbuf_dynflag == NULL) {
> > + rte_errno = ENOENT;
> > + return -1;
> > + }
> > +
> > + if (params != NULL)
> > + memcpy(params, &mbuf_dynflag->params, sizeof(*params));
> > +
> > + return mbuf_dynflag->bitnum;
> > +}
> > +
> > +static int mbuf_dynflag_cmp(const struct rte_mbuf_dynflag *params1,
> > + const struct rte_mbuf_dynflag *params2) {
> > + if (strcmp(params1->name, params2->name))
> > + return -1;
> > + if (params1->flags != params2->flags)
> > + return -1;
> > + return 0;
> > +}
> > +
> > +/* assume tailq is locked */
> > +static int
> > +__rte_mbuf_dynflag_register_bitnum(const struct rte_mbuf_dynflag
> > *params,
> > + unsigned int req)
> > +{
> > + struct mbuf_dynflag_list *mbuf_dynflag_list;
> > + struct mbuf_dynflag_elt *mbuf_dynflag = NULL;
> > + struct rte_tailq_entry *te = NULL;
> > + unsigned int bitnum;
> > + int ret;
> > +
> > + if (shm == NULL && init_shared_mem() < 0)
> > + return -1;
> > +
> > + mbuf_dynflag = __mbuf_dynflag_lookup(params->name);
> > + if (mbuf_dynflag != NULL) {
> > + if (req != UINT_MAX && req != mbuf_dynflag->bitnum) {
> > + rte_errno = EEXIST;
> > + return -1;
> > + }
> > + if (mbuf_dynflag_cmp(params, &mbuf_dynflag->params) < 0)
> > {
> > + rte_errno = EEXIST;
> > + return -1;
> > + }
> > + return mbuf_dynflag->bitnum;
> > + }
> > +
> > + if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
> > + rte_errno = EPERM;
> > + return -1;
> > + }
> > +
> > + if (req == UINT_MAX) {
> > + if (shm->free_flags == 0) {
> > + rte_errno = ENOENT;
> > + return -1;
> > + }
> > + bitnum = rte_bsf64(shm->free_flags);
> > + } else {
> > + if ((shm->free_flags & (1ULL << req)) == 0) {
> > + rte_errno = EBUSY;
> > + return -1;
> > + }
> > + bitnum = req;
> > + }
> > +
> > + mbuf_dynflag_list = RTE_TAILQ_CAST(
> > + mbuf_dynflag_tailq.head, mbuf_dynflag_list);
> > +
> > + te = rte_zmalloc("MBUF_DYNFLAG_TAILQ_ENTRY", sizeof(*te), 0);
> > + if (te == NULL)
> > + return -1;
> > +
> > + mbuf_dynflag = rte_zmalloc("mbuf_dynflag", sizeof(*mbuf_dynflag),
> > 0);
> > + if (mbuf_dynflag == NULL) {
> > + rte_free(te);
> > + return -1;
> > + }
> > +
> > + ret = strlcpy(mbuf_dynflag->params.name, params->name,
> > + sizeof(mbuf_dynflag->params.name));
> > + if (ret < 0 || ret >= (int)sizeof(mbuf_dynflag->params.name)) {
> > + rte_free(mbuf_dynflag);
> > + rte_free(te);
> > + rte_errno = ENAMETOOLONG;
> > + return -1;
> > + }
> > + mbuf_dynflag->bitnum = bitnum;
> > + te->data = mbuf_dynflag;
> > +
> > + TAILQ_INSERT_TAIL(mbuf_dynflag_list, te, next);
> > +
> > + shm->free_flags &= ~(1ULL << bitnum);
> > +
> > + RTE_LOG(DEBUG, MBUF, "Registered dynamic flag %s (fl=0x%x) ->
> > %u\n",
> > + params->name, params->flags, bitnum);
> > +
> > + return bitnum;
> > +}
> > +
> > +int
> > +rte_mbuf_dynflag_register_bitnum(const struct rte_mbuf_dynflag *params,
> > + unsigned int req)
> > +{
> > + int ret;
> > +
> > + if (req != UINT_MAX && req >= 64) {
> > + rte_errno = EINVAL;
> > + return -1;
> > + }
> > +
> > + rte_mcfg_tailq_write_lock();
> > + ret = __rte_mbuf_dynflag_register_bitnum(params, req);
> > + rte_mcfg_tailq_write_unlock();
> > +
> > + return ret;
> > +}
> > +
> > +int
> > +rte_mbuf_dynflag_register(const struct rte_mbuf_dynflag *params) {
> > + return rte_mbuf_dynflag_register_bitnum(params, UINT_MAX); }
> > +
> > +void rte_mbuf_dyn_dump(FILE *out)
> > +{
> > + struct mbuf_dynfield_list *mbuf_dynfield_list;
> > + struct mbuf_dynfield_elt *dynfield;
> > + struct mbuf_dynflag_list *mbuf_dynflag_list;
> > + struct mbuf_dynflag_elt *dynflag;
> > + struct rte_tailq_entry *te;
> > + size_t i;
> > +
> > + rte_mcfg_tailq_write_lock();
> > + init_shared_mem();
> > + fprintf(out, "Reserved fields:\n");
> > + mbuf_dynfield_list = RTE_TAILQ_CAST(
> > + mbuf_dynfield_tailq.head, mbuf_dynfield_list);
> > + TAILQ_FOREACH(te, mbuf_dynfield_list, next) {
> > + dynfield = (struct mbuf_dynfield_elt *)te->data;
> > + fprintf(out, " name=%s offset=%zd size=%zd align=%zd
> > flags=%x\n",
> > + dynfield->params.name, dynfield->offset,
> > + dynfield->params.size, dynfield->params.align,
> > + dynfield->params.flags);
> > + }
> > + fprintf(out, "Reserved flags:\n");
> > + mbuf_dynflag_list = RTE_TAILQ_CAST(
> > + mbuf_dynflag_tailq.head, mbuf_dynflag_list);
> > + TAILQ_FOREACH(te, mbuf_dynflag_list, next) {
> > + dynflag = (struct mbuf_dynflag_elt *)te->data;
> > + fprintf(out, " name=%s bitnum=%u flags=%x\n",
> > + dynflag->params.name, dynflag->bitnum,
> > + dynflag->params.flags);
> > + }
> > + fprintf(out, "Free space in mbuf (0 = free, value = zone
> > alignment):\n");
> > + for (i = 0; i < sizeof(struct rte_mbuf); i++) {
> > + if ((i % 8) == 0)
> > + fprintf(out, " %4.4zx: ", i);
> > + fprintf(out, "%2.2x%s", shm->free_space[i],
> > + (i % 8 != 7) ? " " : "\n");
> > + }
> > + rte_mcfg_tailq_write_unlock();
> > +}
> > diff --git a/lib/librte_mbuf/rte_mbuf_dyn.h
> > b/lib/librte_mbuf/rte_mbuf_dyn.h new file mode 100644 index
> > 000000000..307613c96
> > --- /dev/null
> > +++ b/lib/librte_mbuf/rte_mbuf_dyn.h
> > @@ -0,0 +1,226 @@
> > +/* SPDX-License-Identifier: BSD-3-Clause
> > + * Copyright 2019 6WIND S.A.
> > + */
> > +
> > +#ifndef _RTE_MBUF_DYN_H_
> > +#define _RTE_MBUF_DYN_H_
> > +
> > +/**
> > + * @file
> > + * RTE Mbuf dynamic fields and flags
> > + *
> > + * Many features require to store data inside the mbuf. As the room in
> > + * mbuf structure is limited, it is not possible to have a field for
> > + * each feature. Also, changing fields in the mbuf structure can break
> > + * the API or ABI.
> > + *
> > + * This module addresses this issue, by enabling the dynamic
> > + * registration of fields or flags:
> > + *
> > + * - a dynamic field is a named area in the rte_mbuf structure, with a
> > + * given size (>= 1 byte) and alignment constraint.
> > + * - a dynamic flag is a named bit in the rte_mbuf structure, stored
> > + * in mbuf->ol_flags.
> > + *
> > + * The typical use case is when a specific offload feature requires to
> > + * register a dedicated offload field in the mbuf structure, and adding
> > + * a static field or flag is not justified.
> > + *
> > + * Example of use:
> > + *
> > + * - A rte_mbuf_dynfield structure is defined, containing the parameters
> > + * of the dynamic field to be registered:
> > + * const struct rte_mbuf_dynfield rte_dynfield_my_feature = { ... };
> > + * - The application initializes the PMD, and asks for this feature
> > + * at port initialization by passing DEV_RX_OFFLOAD_MY_FEATURE in
> > + * rxconf. This will make the PMD to register the field by calling
> > + * rte_mbuf_dynfield_register(&rte_dynfield_my_feature). The PMD
> > + * stores the returned offset.
> > + * - The application that uses the offload feature also registers
> > + * the field to retrieve the same offset.
> > + * - When the PMD receives a packet, it can set the field:
> > + * *RTE_MBUF_DYNFIELD(m, offset, <type *>) = value;
> > + * - In the main loop, the application can retrieve the value with
> > + * the same macro.
> > + *
> > + * To avoid wasting space, the dynamic fields or flags must only be
> > + * reserved on demand, when an application asks for the related feature.
> > + *
> > + * The registration can be done at any moment, but it is not possible
> > + * to unregister fields or flags for now.
> > + *
> > + * A dynamic field can be reserved and used by an application only.
> > + * It can for instance be a packet mark.
> > + */
> > +
> > +#include <sys/types.h>
> > +/**
> > + * Maximum length of the dynamic field or flag string.
> > + */
> > +#define RTE_MBUF_DYN_NAMESIZE 64
> > +
> > +/**
> > + * Structure describing the parameters of a mbuf dynamic field.
> > + */
> > +struct rte_mbuf_dynfield {
> > + char name[RTE_MBUF_DYN_NAMESIZE]; /**< Name of the field. */
> > + size_t size; /**< The number of bytes to reserve. */
> > + size_t align; /**< The alignment constraint (power of 2). */
> > + unsigned int flags; /**< Reserved for future use, must be 0. */ };
> > +
> > +/**
> > + * Structure describing the parameters of a mbuf dynamic flag.
> > + */
> > +struct rte_mbuf_dynflag {
> > + char name[RTE_MBUF_DYN_NAMESIZE]; /**< Name of the dynamic
> > flag. */
> > + unsigned int flags; /**< Reserved for future use, must be 0. */ };
> > +
> > +/**
> > + * Register space for a dynamic field in the mbuf structure.
> > + *
> > + * If the field is already registered (same name and parameters), its
> > + * offset is returned.
> > + *
> > + * @param params
> > + * A structure containing the requested parameters (name, size,
> > + * alignment constraint and flags).
> > + * @return
> > + * The offset in the mbuf structure, or -1 on error.
> > + * Possible values for rte_errno:
> > + * - EINVAL: invalid parameters (size, align, or flags).
> > + * - EEXIST: this name is already register with different parameters.
> > + * - EPERM: called from a secondary process.
> > + * - ENOENT: not enough room in mbuf.
> > + * - ENOMEM: allocation failure.
> > + * - ENAMETOOLONG: name does not ends with \0.
> > + */
> > +__rte_experimental
> > +int rte_mbuf_dynfield_register(const struct rte_mbuf_dynfield *params);
> > +
> > +/**
> > + * Register space for a dynamic field in the mbuf structure at offset.
> > + *
> > + * If the field is already registered (same name, parameters and
> > +offset),
> > + * the offset is returned.
> > + *
> > + * @param params
> > + * A structure containing the requested parameters (name, size,
> > + * alignment constraint and flags).
> > + * @param offset
> > + * The requested offset. Ignored if SIZE_MAX is passed.
> > + * @return
> > + * The offset in the mbuf structure, or -1 on error.
> > + * Possible values for rte_errno:
> > + * - EINVAL: invalid parameters (size, align, flags, or offset).
> > + * - EEXIST: this name is already register with different parameters.
> > + * - EBUSY: the requested offset cannot be used.
> > + * - EPERM: called from a secondary process.
> > + * - ENOENT: not enough room in mbuf.
> > + * - ENOMEM: allocation failure.
> > + * - ENAMETOOLONG: name does not ends with \0.
> > + */
> > +__rte_experimental
> > +int rte_mbuf_dynfield_register_offset(const struct rte_mbuf_dynfield
> > *params,
> > + size_t offset);
> > +
> > +/**
> > + * Lookup for a registered dynamic mbuf field.
> > + *
> > + * @param name
> > + * A string identifying the dynamic field.
> > + * @param params
> > + * If not NULL, and if the lookup is successful, the structure is
> > + * filled with the parameters of the dynamic field.
> > + * @return
> > + * The offset of this field in the mbuf structure, or -1 on error.
> > + * Possible values for rte_errno:
> > + * - ENOENT: no dynamic field matches this name.
> > + */
> > +__rte_experimental
> > +int rte_mbuf_dynfield_lookup(const char *name,
> > + struct rte_mbuf_dynfield *params);
> > +
> > +/**
> > + * Register a dynamic flag in the mbuf structure.
> > + *
> > + * If the flag is already registered (same name and parameters), its
> > + * bitnum is returned.
> > + *
> > + * @param params
> > + * A structure containing the requested parameters of the dynamic
> > + * flag (name and options).
> > + * @return
> > + * The number of the reserved bit, or -1 on error.
> > + * Possible values for rte_errno:
> > + * - EINVAL: invalid parameters (size, align, or flags).
> > + * - EEXIST: this name is already register with different parameters.
> > + * - EPERM: called from a secondary process.
> > + * - ENOENT: no more flag available.
> > + * - ENOMEM: allocation failure.
> > + * - ENAMETOOLONG: name is longer than RTE_MBUF_DYN_NAMESIZE -
> > 1.
> > + */
> > +__rte_experimental
> > +int rte_mbuf_dynflag_register(const struct rte_mbuf_dynflag *params);
> > +
> > +/**
> > + * Register a dynamic flag in the mbuf structure specifying bitnum.
> > + *
> > + * If the flag is already registered (same name, parameters and
> > +bitnum),
> > + * the bitnum is returned.
> > + *
> > + * @param params
> > + * A structure containing the requested parameters of the dynamic
> > + * flag (name and options).
> > + * @param bitnum
> > + * The requested bitnum. Ignored if UINT_MAX is passed.
> > + * @return
> > + * The number of the reserved bit, or -1 on error.
> > + * Possible values for rte_errno:
> > + * - EINVAL: invalid parameters (size, align, or flags).
> > + * - EEXIST: this name is already register with different parameters.
> > + * - EBUSY: the requested bitnum cannot be used.
> > + * - EPERM: called from a secondary process.
> > + * - ENOENT: no more flag available.
> > + * - ENOMEM: allocation failure.
> > + * - ENAMETOOLONG: name is longer than RTE_MBUF_DYN_NAMESIZE -
> > 1.
> > + */
> > +__rte_experimental
> > +int rte_mbuf_dynflag_register_bitnum(const struct rte_mbuf_dynflag
> > *params,
> > + unsigned int bitnum);
> > +
> > +/**
> > + * Lookup for a registered dynamic mbuf flag.
> > + *
> > + * @param name
> > + * A string identifying the dynamic flag.
> > + * @param params
> > + * If not NULL, and if the lookup is successful, the structure is
> > + * filled with the parameters of the dynamic flag.
> > + * @return
> > + * The offset of this flag in the mbuf structure, or -1 on error.
> > + * Possible values for rte_errno:
> > + * - ENOENT: no dynamic flag matches this name.
> > + */
> > +__rte_experimental
> > +int rte_mbuf_dynflag_lookup(const char *name,
> > + struct rte_mbuf_dynflag *params);
> > +
> > +/**
> > + * Helper macro to access to a dynamic field.
> > + */
> > +#define RTE_MBUF_DYNFIELD(m, offset, type) ((type)((uintptr_t)(m) +
> > +(offset)))
> > +
> > +/**
> > + * Dump the status of dynamic fields and flags.
> > + *
> > + * @param out
> > + * The stream where the status is displayed.
> > + */
> > +__rte_experimental
> > +void rte_mbuf_dyn_dump(FILE *out);
> > +
> > +/* Placeholder for dynamic fields and flags declarations. */
> > +
> > +#endif
> > diff --git a/lib/librte_mbuf/rte_mbuf_version.map
> > b/lib/librte_mbuf/rte_mbuf_version.map
> > index 519fead35..9bf5ca37a 100644
> > --- a/lib/librte_mbuf/rte_mbuf_version.map
> > +++ b/lib/librte_mbuf/rte_mbuf_version.map
> > @@ -58,6 +58,13 @@ EXPERIMENTAL {
> > global:
> >
> > rte_mbuf_check;
> > + rte_mbuf_dynfield_lookup;
> > + rte_mbuf_dynfield_register;
> > + rte_mbuf_dynfield_register_offset;
> > + rte_mbuf_dynflag_lookup;
> > + rte_mbuf_dynflag_register;
> > + rte_mbuf_dynflag_register_bitnum;
> > + rte_mbuf_dyn_dump;
> > rte_pktmbuf_copy;
> >
> > } DPDK_18.08;
> > --
> > 2.20.1
>
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