Patch looks good to me Acked-by: Kamalakshitha Aligeri <kamalakshitha.alig...@arm.com>
> -----Original Message----- > From: Morten Brørup <m...@smartsharesystems.com> > Sent: Monday, February 13, 2023 4:25 AM > To: olivier.m...@6wind.com; andrew.rybche...@oktetlabs.ru; Honnappa > Nagarahalli <honnappa.nagaraha...@arm.com>; Kamalakshitha Aligeri > <kamalakshitha.alig...@arm.com>; bruce.richard...@intel.com; > konstantin.anan...@huawei.com; dev@dpdk.org > Cc: nd <n...@arm.com>; david.march...@redhat.com; Morten Brørup > <m...@smartsharesystems.com> > Subject: [PATCH v9] mempool cache: add zero-copy get and put functions > > Zero-copy access to mempool caches is beneficial for PMD performance, and > must be provided by the mempool library to fix [Bug 1052] without a > performance regression. > > [Bug 1052]: https://bugs.dpdk.org/show_bug.cgi?id=1052 > > Bugzilla ID: 1052 > > Signed-off-by: Morten Brørup <m...@smartsharesystems.com> > Acked-by: Konstantin Ananyev <konstantin.v.anan...@yandex.ru> > Acked-by: Chengwen Feng <fengcheng...@huawei.com> > > v9: > * Also set rte_errno in zero-copy put function, if returning NULL. > (Honnappa) > * Revert v3 comparison to prevent overflow if n is really huge and len is > non-zero. (Olivier) > v8: > * Actually include the rte_errno header file. > Note to self: The changes only take effect on the disk after the file in > the text editor has been saved. > v7: > * Fix typo in function description. (checkpatch) > * Zero-copy functions may set rte_errno; include rte_errno header file. > (ci/loongarch-compilation) > v6: > * Improve description of the 'n' parameter to the zero-copy get function. > (Konstantin, Bruce) > * The caches used for zero-copy may not be user-owned, so remove this > word > from the function descriptions. (Kamalakshitha) > v5: > * Bugfix: Compare zero-copy get request to the cache size instead of the > flush threshold; otherwise refill could overflow the memory allocated > for the cache. (Andrew) > * Split the zero-copy put function into an internal function doing the > work, and a public function with trace. > * Avoid code duplication by rewriting rte_mempool_do_generic_put() to use > the internal zero-copy put function. (Andrew) > * Corrected the return type of rte_mempool_cache_zc_put_bulk() from > void * > to void **; it returns a pointer to an array of objects. > * Fix coding style: Add missing curly brackets. (Andrew) > v4: > * Fix checkpatch warnings. > v3: > * Bugfix: Respect the cache size; compare to the flush threshold instead > of RTE_MEMPOOL_CACHE_MAX_SIZE. > * Added 'rewind' function for incomplete 'put' operations. (Konstantin) > * Replace RTE_ASSERTs with runtime checks of the request size. > Instead of failing, return NULL if the request is too big. (Konstantin) > * Modified comparison to prevent overflow if n is really huge and len is > non-zero. (Andrew) > * Updated the comments in the code. > v2: > * Fix checkpatch warnings. > * Fix missing registration of trace points. > * The functions are inline, so they don't go into the map file. > v1 changes from the RFC: > * Removed run-time parameter checks. (Honnappa) > This is a hot fast path function; requiring correct application > behaviour, i.e. function parameters must be valid. > * Added RTE_ASSERT for parameters instead. > Code for this is only generated if built with RTE_ENABLE_ASSERT. > * Removed fallback when 'cache' parameter is not set. (Honnappa) > * Chose the simple get function; i.e. do not move the existing objects in > the cache to the top of the new stack, just leave them at the bottom. > * Renamed the functions. Other suggestions are welcome, of course. ;-) > * Updated the function descriptions. > * Added the functions to trace_fp and version.map. > --- > lib/mempool/mempool_trace_points.c | 9 ++ > lib/mempool/rte_mempool.h | 239 +++++++++++++++++++++++++---- > lib/mempool/rte_mempool_trace_fp.h | 23 +++ > lib/mempool/version.map | 5 + > 4 files changed, 247 insertions(+), 29 deletions(-) > > diff --git a/lib/mempool/mempool_trace_points.c > b/lib/mempool/mempool_trace_points.c > index 4ad76deb34..83d353a764 100644 > --- a/lib/mempool/mempool_trace_points.c > +++ b/lib/mempool/mempool_trace_points.c > @@ -77,3 +77,12 @@ > RTE_TRACE_POINT_REGISTER(rte_mempool_trace_ops_free, > > RTE_TRACE_POINT_REGISTER(rte_mempool_trace_set_ops_byname, > lib.mempool.set.ops.byname) > + > +RTE_TRACE_POINT_REGISTER(rte_mempool_trace_cache_zc_put_bulk, > + lib.mempool.cache.zc.put.bulk) > + > +RTE_TRACE_POINT_REGISTER(rte_mempool_trace_cache_zc_put_rewind, > + lib.mempool.cache.zc.put.rewind) > + > +RTE_TRACE_POINT_REGISTER(rte_mempool_trace_cache_zc_get_bulk, > + lib.mempool.cache.zc.get.bulk) > diff --git a/lib/mempool/rte_mempool.h b/lib/mempool/rte_mempool.h > index 9f530db24b..94f895c329 100644 > --- a/lib/mempool/rte_mempool.h > +++ b/lib/mempool/rte_mempool.h > @@ -42,6 +42,7 @@ > #include <rte_config.h> > #include <rte_spinlock.h> > #include <rte_debug.h> > +#include <rte_errno.h> > #include <rte_lcore.h> > #include <rte_branch_prediction.h> > #include <rte_ring.h> > @@ -1346,6 +1347,199 @@ rte_mempool_cache_flush(struct > rte_mempool_cache *cache, > cache->len = 0; > } > > + > +/** > + * @internal used by rte_mempool_cache_zc_put_bulk() and > rte_mempool_do_generic_put(). > + * > + * Zero-copy put objects in a mempool cache backed by the specified > mempool. > + * > + * @param cache > + * A pointer to the mempool cache. > + * @param mp > + * A pointer to the mempool. > + * @param n > + * The number of objects to be put in the mempool cache. > + * @return > + * The pointer to where to put the objects in the mempool cache. > + * NULL, with rte_errno set to EINVAL, if the request itself is too big > + * for the cache, i.e. exceeds the cache flush threshold. > + */ > +static __rte_always_inline void ** > +__rte_mempool_cache_zc_put_bulk(struct rte_mempool_cache *cache, > + struct rte_mempool *mp, > + unsigned int n) > +{ > + void **cache_objs; > + > + RTE_ASSERT(cache != NULL); > + RTE_ASSERT(mp != NULL); > + > + if (cache->len + n <= cache->flushthresh) { > + /* > + * The objects can be added to the cache without crossing > the > + * flush threshold. > + */ > + cache_objs = &cache->objs[cache->len]; > + cache->len += n; > + } else if (likely(n <= cache->flushthresh)) { > + /* > + * The request itself fits into the cache. > + * But first, the cache must be flushed to the backend, so > + * adding the objects does not cross the flush threshold. > + */ > + cache_objs = &cache->objs[0]; > + rte_mempool_ops_enqueue_bulk(mp, cache_objs, cache- > >len); > + cache->len = n; > + } else { > + /* The request itself is too big for the cache. */ > + rte_errno = EINVAL; > + return NULL; > + } > + > + RTE_MEMPOOL_CACHE_STAT_ADD(cache, put_bulk, 1); > + RTE_MEMPOOL_CACHE_STAT_ADD(cache, put_objs, n); > + > + return cache_objs; > +} > + > +/** > + * @warning > + * @b EXPERIMENTAL: This API may change, or be removed, without prior > notice. > + * > + * Zero-copy put objects in a mempool cache backed by the specified > mempool. > + * > + * @param cache > + * A pointer to the mempool cache. > + * @param mp > + * A pointer to the mempool. > + * @param n > + * The number of objects to be put in the mempool cache. > + * @return > + * The pointer to where to put the objects in the mempool cache. > + * NULL if the request itself is too big for the cache, i.e. > + * exceeds the cache flush threshold. > + */ > +__rte_experimental > +static __rte_always_inline void ** > +rte_mempool_cache_zc_put_bulk(struct rte_mempool_cache *cache, > + struct rte_mempool *mp, > + unsigned int n) > +{ > + RTE_ASSERT(cache != NULL); > + RTE_ASSERT(mp != NULL); > + > + rte_mempool_trace_cache_zc_put_bulk(cache, mp, n); > + return __rte_mempool_cache_zc_put_bulk(cache, mp, n); } > + > +/** > + * @warning > + * @b EXPERIMENTAL: This API may change, or be removed, without prior > notice. > + * > + * Zero-copy un-put objects in a mempool cache. > + * > + * @param cache > + * A pointer to the mempool cache. > + * @param n > + * The number of objects not put in the mempool cache after calling > + * rte_mempool_cache_zc_put_bulk(). > + */ > +__rte_experimental > +static __rte_always_inline void > +rte_mempool_cache_zc_put_rewind(struct rte_mempool_cache *cache, > + unsigned int n) > +{ > + RTE_ASSERT(cache != NULL); > + RTE_ASSERT(n <= cache->len); > + > + rte_mempool_trace_cache_zc_put_rewind(cache, n); > + > + cache->len -= n; > + > + RTE_MEMPOOL_CACHE_STAT_ADD(cache, put_objs, (int)-n); } > + > +/** > + * @warning > + * @b EXPERIMENTAL: This API may change, or be removed, without prior > notice. > + * > + * Zero-copy get objects from a mempool cache backed by the specified > mempool. > + * > + * @param cache > + * A pointer to the mempool cache. > + * @param mp > + * A pointer to the mempool. > + * @param n > + * The number of objects to be made available for extraction from the > mempool cache. > + * @return > + * The pointer to the objects in the mempool cache. > + * NULL on error; i.e. the cache + the pool does not contain 'n' objects. > + * With rte_errno set to the error code of the mempool dequeue function, > + * or EINVAL if the request itself is too big for the cache, i.e. > + * exceeds the cache flush threshold. > + */ > +__rte_experimental > +static __rte_always_inline void * > +rte_mempool_cache_zc_get_bulk(struct rte_mempool_cache *cache, > + struct rte_mempool *mp, > + unsigned int n) > +{ > + unsigned int len, size; > + > + RTE_ASSERT(cache != NULL); > + RTE_ASSERT(mp != NULL); > + > + rte_mempool_trace_cache_zc_get_bulk(cache, mp, n); > + > + len = cache->len; > + size = cache->size; > + > + if (n <= len) { > + /* The request can be satisfied from the cache as is. */ > + len -= n; > + } else if (likely(n <= size)) { > + /* > + * The request itself can be satisfied from the cache. > + * But first, the cache must be filled from the backend; > + * fetch size + requested - len objects. > + */ > + int ret; > + > + ret = rte_mempool_ops_dequeue_bulk(mp, &cache- > >objs[len], size + n - len); > + if (unlikely(ret < 0)) { > + /* > + * We are buffer constrained. > + * Do not fill the cache, just satisfy the request. > + */ > + ret = rte_mempool_ops_dequeue_bulk(mp, > &cache->objs[len], n - len); > + if (unlikely(ret < 0)) { > + /* Unable to satisfy the request. */ > + > + RTE_MEMPOOL_STAT_ADD(mp, > get_fail_bulk, 1); > + RTE_MEMPOOL_STAT_ADD(mp, > get_fail_objs, n); > + > + rte_errno = -ret; > + return NULL; > + } > + > + len = 0; > + } else { > + len = size; > + } > + } else { > + /* The request itself is too big for the cache. */ > + rte_errno = EINVAL; > + return NULL; > + } > + > + cache->len = len; > + > + RTE_MEMPOOL_CACHE_STAT_ADD(cache, get_success_bulk, 1); > + RTE_MEMPOOL_CACHE_STAT_ADD(cache, get_success_objs, n); > + > + return &cache->objs[len]; > +} > + > /** > * @internal Put several objects back in the mempool; used internally. > * @param mp > @@ -1364,32 +1558,25 @@ rte_mempool_do_generic_put(struct > rte_mempool *mp, void * const *obj_table, { > void **cache_objs; > > - /* No cache provided */ > - if (unlikely(cache == NULL)) > - goto driver_enqueue; > + /* No cache provided? */ > + if (unlikely(cache == NULL)) { > + /* Increment stats now, adding in mempool always succeeds. > */ > + RTE_MEMPOOL_STAT_ADD(mp, put_bulk, 1); > + RTE_MEMPOOL_STAT_ADD(mp, put_objs, n); > > - /* increment stat now, adding in mempool always success */ > - RTE_MEMPOOL_CACHE_STAT_ADD(cache, put_bulk, 1); > - RTE_MEMPOOL_CACHE_STAT_ADD(cache, put_objs, n); > + goto driver_enqueue; > + } > > - /* The request itself is too big for the cache */ > - if (unlikely(n > cache->flushthresh)) > - goto driver_enqueue_stats_incremented; > + /* Prepare to add the objects to the cache. */ > + cache_objs = __rte_mempool_cache_zc_put_bulk(cache, mp, n); > > - /* > - * The cache follows the following algorithm: > - * 1. If the objects cannot be added to the cache without crossing > - * the flush threshold, flush the cache to the backend. > - * 2. Add the objects to the cache. > - */ > + /* The request itself is too big for the cache? */ > + if (unlikely(cache_objs == NULL)) { > + /* Increment stats now, adding in mempool always succeeds. > */ > + RTE_MEMPOOL_CACHE_STAT_ADD(cache, put_bulk, 1); > + RTE_MEMPOOL_CACHE_STAT_ADD(cache, put_objs, n); > > - if (cache->len + n <= cache->flushthresh) { > - cache_objs = &cache->objs[cache->len]; > - cache->len += n; > - } else { > - cache_objs = &cache->objs[0]; > - rte_mempool_ops_enqueue_bulk(mp, cache_objs, cache- > >len); > - cache->len = n; > + goto driver_enqueue; > } > > /* Add the objects to the cache. */ > @@ -1399,13 +1586,7 @@ rte_mempool_do_generic_put(struct > rte_mempool *mp, void * const *obj_table, > > driver_enqueue: > > - /* increment stat now, adding in mempool always success */ > - RTE_MEMPOOL_STAT_ADD(mp, put_bulk, 1); > - RTE_MEMPOOL_STAT_ADD(mp, put_objs, n); > - > -driver_enqueue_stats_incremented: > - > - /* push objects to the backend */ > + /* Push the objects to the backend. */ > rte_mempool_ops_enqueue_bulk(mp, obj_table, n); } > > diff --git a/lib/mempool/rte_mempool_trace_fp.h > b/lib/mempool/rte_mempool_trace_fp.h > index ed060e887c..14666457f7 100644 > --- a/lib/mempool/rte_mempool_trace_fp.h > +++ b/lib/mempool/rte_mempool_trace_fp.h > @@ -109,6 +109,29 @@ RTE_TRACE_POINT_FP( > rte_trace_point_emit_ptr(mempool); > ) > > +RTE_TRACE_POINT_FP( > + rte_mempool_trace_cache_zc_put_bulk, > + RTE_TRACE_POINT_ARGS(void *cache, void *mempool, uint32_t > nb_objs), > + rte_trace_point_emit_ptr(cache); > + rte_trace_point_emit_ptr(mempool); > + rte_trace_point_emit_u32(nb_objs); > +) > + > +RTE_TRACE_POINT_FP( > + rte_mempool_trace_cache_zc_put_rewind, > + RTE_TRACE_POINT_ARGS(void *cache, uint32_t nb_objs), > + rte_trace_point_emit_ptr(cache); > + rte_trace_point_emit_u32(nb_objs); > +) > + > +RTE_TRACE_POINT_FP( > + rte_mempool_trace_cache_zc_get_bulk, > + RTE_TRACE_POINT_ARGS(void *cache, void *mempool, uint32_t > nb_objs), > + rte_trace_point_emit_ptr(cache); > + rte_trace_point_emit_ptr(mempool); > + rte_trace_point_emit_u32(nb_objs); > +) > + > #ifdef __cplusplus > } > #endif > diff --git a/lib/mempool/version.map b/lib/mempool/version.map index > b67d7aace7..1383ae6db2 100644 > --- a/lib/mempool/version.map > +++ b/lib/mempool/version.map > @@ -63,6 +63,11 @@ EXPERIMENTAL { > __rte_mempool_trace_ops_alloc; > __rte_mempool_trace_ops_free; > __rte_mempool_trace_set_ops_byname; > + > + # added in 23.03 > + __rte_mempool_trace_cache_zc_put_bulk; > + __rte_mempool_trace_cache_zc_put_rewind; > + __rte_mempool_trace_cache_zc_get_bulk; > }; > > INTERNAL { > -- > 2.17.1
