[v2,2/6] lib/ring: add template to support different element sizes

Message ID 20190906190510.11146-3-honnappa.nagarahalli@arm.com
State New
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Series
  • lib/ring: templates to support custom element size
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Commit Message

Honnappa Nagarahalli Sept. 6, 2019, 7:05 p.m.
Add templates to support creating ring APIs with different
ring element sizes.

Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>

Reviewed-by: Dharmik Thakkar <dharmik.thakkar@arm.com>

Reviewed-by: Gavin Hu <gavin.hu@arm.com>

Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>

---
 lib/librte_ring/Makefile            |   4 +-
 lib/librte_ring/meson.build         |   4 +-
 lib/librte_ring/rte_ring_template.c |  46 ++++
 lib/librte_ring/rte_ring_template.h | 330 ++++++++++++++++++++++++++++
 4 files changed, 382 insertions(+), 2 deletions(-)
 create mode 100644 lib/librte_ring/rte_ring_template.c
 create mode 100644 lib/librte_ring/rte_ring_template.h

-- 
2.17.1

Comments

Stephen Hemminger Sept. 8, 2019, 7:44 p.m. | #1
On Fri,  6 Sep 2019 14:05:06 -0500
Honnappa Nagarahalli <honnappa.nagarahalli@arm.com> wrote:

> Add templates to support creating ring APIs with different

> ring element sizes.

> 

> Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>

> Reviewed-by: Dharmik Thakkar <dharmik.thakkar@arm.com>

> Reviewed-by: Gavin Hu <gavin.hu@arm.com>

> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>


Understand the desire for generic code, but macro's are much harder to maintain
and debug. Would it be possible to use inline code taking a size argument
and let compiler optimizations with constant folding do the same thing.

Sorry, I vote NO for large scale use of macro's.
Bruce Richardson Sept. 9, 2019, 9:01 a.m. | #2
On Sun, Sep 08, 2019 at 08:44:36PM +0100, Stephen Hemminger wrote:
> On Fri,  6 Sep 2019 14:05:06 -0500

> Honnappa Nagarahalli <honnappa.nagarahalli@arm.com> wrote:

> 

> > Add templates to support creating ring APIs with different

> > ring element sizes.

> > 

> > Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>

> > Reviewed-by: Dharmik Thakkar <dharmik.thakkar@arm.com>

> > Reviewed-by: Gavin Hu <gavin.hu@arm.com>

> > Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>

> 

> Understand the desire for generic code, but macro's are much harder to maintain

> and debug. Would it be possible to use inline code taking a size argument

> and let compiler optimizations with constant folding do the same thing.

> 

> Sorry, I vote NO for large scale use of macro's.


I would tend to agree. This use of macros makes the code very awkward to
read and understand.
Honnappa Nagarahalli Sept. 9, 2019, 10:33 p.m. | #3
> -----Original Message-----

> From: Bruce Richardson <bruce.richardson@intel.com>

> Sent: Monday, September 9, 2019 4:01 AM

> To: Stephen Hemminger <stephen@networkplumber.org>

> Cc: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>;

> olivier.matz@6wind.com; yipeng1.wang@intel.com;

> sameh.gobriel@intel.com; pablo.de.lara.guarch@intel.com; dev@dpdk.org;

> pbhagavatula@marvell.com; jerinj@marvell.com

> Subject: Re: [dpdk-dev] [PATCH v2 2/6] lib/ring: add template to support

> different element sizes

> 

> On Sun, Sep 08, 2019 at 08:44:36PM +0100, Stephen Hemminger wrote:

> > On Fri,  6 Sep 2019 14:05:06 -0500

> > Honnappa Nagarahalli <honnappa.nagarahalli@arm.com> wrote:

> >

> > > Add templates to support creating ring APIs with different ring

> > > element sizes.

> > >

> > > Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>

> > > Reviewed-by: Dharmik Thakkar <dharmik.thakkar@arm.com>

> > > Reviewed-by: Gavin Hu <gavin.hu@arm.com>

> > > Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>

> >

> > Understand the desire for generic code, but macro's are much harder to

> > maintain and debug. Would it be possible to use inline code taking a

> > size argument and let compiler optimizations with constant folding do the

> same thing.

> >

> > Sorry, I vote NO for large scale use of macro's.

> 

> I would tend to agree. This use of macros makes the code very awkward to

> read and understand.

Stephen, Bruce,  thank you for your feedback. Looks like we at least have an agreement on the problem definition, hopefully we can find a solution. I will try to rework this and get back with solutions/problems.

Patch

diff --git a/lib/librte_ring/Makefile b/lib/librte_ring/Makefile
index 4c8410229..818898110 100644
--- a/lib/librte_ring/Makefile
+++ b/lib/librte_ring/Makefile
@@ -19,6 +19,8 @@  SRCS-$(CONFIG_RTE_LIBRTE_RING) := rte_ring.c
 # install includes
 SYMLINK-$(CONFIG_RTE_LIBRTE_RING)-include := rte_ring.h \
 					rte_ring_generic.h \
-					rte_ring_c11_mem.h
+					rte_ring_c11_mem.h \
+					rte_ring_template.h \
+					rte_ring_template.c
 
 include $(RTE_SDK)/mk/rte.lib.mk
diff --git a/lib/librte_ring/meson.build b/lib/librte_ring/meson.build
index 74219840a..e4e208a7c 100644
--- a/lib/librte_ring/meson.build
+++ b/lib/librte_ring/meson.build
@@ -5,7 +5,9 @@  version = 2
 sources = files('rte_ring.c')
 headers = files('rte_ring.h',
 		'rte_ring_c11_mem.h',
-		'rte_ring_generic.h')
+		'rte_ring_generic.h',
+		'rte_ring_template.h',
+		'rte_ring_template.c')
 
 # rte_ring_create_elem and rte_ring_get_memsize_elem are experimental
 allow_experimental_apis = true
diff --git a/lib/librte_ring/rte_ring_template.c b/lib/librte_ring/rte_ring_template.c
new file mode 100644
index 000000000..1ca593f95
--- /dev/null
+++ b/lib/librte_ring/rte_ring_template.c
@@ -0,0 +1,46 @@ 
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright (c) 2019 Arm Limited
+ */
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <string.h>
+#include <stdint.h>
+#include <inttypes.h>
+#include <errno.h>
+#include <sys/queue.h>
+
+#include <rte_common.h>
+#include <rte_log.h>
+#include <rte_memory.h>
+#include <rte_memzone.h>
+#include <rte_malloc.h>
+#include <rte_launch.h>
+#include <rte_eal.h>
+#include <rte_eal_memconfig.h>
+#include <rte_atomic.h>
+#include <rte_per_lcore.h>
+#include <rte_lcore.h>
+#include <rte_branch_prediction.h>
+#include <rte_errno.h>
+#include <rte_string_fns.h>
+#include <rte_spinlock.h>
+#include <rte_tailq.h>
+
+#include "rte_ring.h"
+
+/* return the size of memory occupied by a ring */
+ssize_t
+__RTE_RING_CONCAT(rte_ring_get_memsize)(unsigned count)
+{
+	return rte_ring_get_memsize_elem(count, RTE_RING_TMPLT_ELEM_SIZE);
+}
+
+/* create the ring */
+struct rte_ring *
+__RTE_RING_CONCAT(rte_ring_create)(const char *name, unsigned count,
+		int socket_id, unsigned flags)
+{
+	return rte_ring_create_elem(name, count, RTE_RING_TMPLT_ELEM_SIZE,
+		socket_id, flags);
+}
diff --git a/lib/librte_ring/rte_ring_template.h b/lib/librte_ring/rte_ring_template.h
new file mode 100644
index 000000000..5002a7485
--- /dev/null
+++ b/lib/librte_ring/rte_ring_template.h
@@ -0,0 +1,330 @@ 
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright (c) 2019 Arm Limited
+ */
+
+#ifndef _RTE_RING_TEMPLATE_H_
+#define _RTE_RING_TEMPLATE_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdio.h>
+#include <stdint.h>
+#include <sys/queue.h>
+#include <errno.h>
+#include <rte_common.h>
+#include <rte_config.h>
+#include <rte_memory.h>
+#include <rte_lcore.h>
+#include <rte_atomic.h>
+#include <rte_branch_prediction.h>
+#include <rte_memzone.h>
+#include <rte_pause.h>
+#include <rte_ring.h>
+
+/* Ring API suffix name - used to append to API names */
+#ifndef RTE_RING_TMPLT_API_SUFFIX
+#error RTE_RING_TMPLT_API_SUFFIX not defined
+#endif
+
+/* Ring's element size in bits, should be a power of 2 */
+#ifndef RTE_RING_TMPLT_ELEM_SIZE
+#error RTE_RING_TMPLT_ELEM_SIZE not defined
+#endif
+
+/* Type of ring elements */
+#ifndef RTE_RING_TMPLT_ELEM_TYPE
+#error RTE_RING_TMPLT_ELEM_TYPE not defined
+#endif
+
+#define _rte_fuse(a, b) a##_##b
+#define __rte_fuse(a, b) _rte_fuse(a, b)
+#define __RTE_RING_CONCAT(a) __rte_fuse(a, RTE_RING_TMPLT_API_SUFFIX)
+
+/* Calculate the memory size needed for a ring */
+RTE_RING_TMPLT_EXPERIMENTAL
+ssize_t __RTE_RING_CONCAT(rte_ring_get_memsize)(unsigned count);
+
+/* Create a new ring named *name* in memory. */
+RTE_RING_TMPLT_EXPERIMENTAL
+struct rte_ring *
+__RTE_RING_CONCAT(rte_ring_create)(const char *name, unsigned count,
+					int socket_id, unsigned flags);
+
+/**
+ * @internal Enqueue several objects on the ring
+ */
+static __rte_always_inline unsigned int
+__RTE_RING_CONCAT(__rte_ring_do_enqueue)(struct rte_ring *r,
+		RTE_RING_TMPLT_ELEM_TYPE const *obj_table, unsigned int n,
+		enum rte_ring_queue_behavior behavior, unsigned int is_sp,
+		unsigned int *free_space)
+{
+	uint32_t prod_head, prod_next;
+	uint32_t free_entries;
+
+	n = __rte_ring_move_prod_head(r, is_sp, n, behavior,
+			&prod_head, &prod_next, &free_entries);
+	if (n == 0)
+		goto end;
+
+	ENQUEUE_PTRS(r, &r[1], prod_head, obj_table, n,
+		RTE_RING_TMPLT_ELEM_TYPE);
+
+	update_tail(&r->prod, prod_head, prod_next, is_sp, 1);
+end:
+	if (free_space != NULL)
+		*free_space = free_entries - n;
+	return n;
+}
+
+/**
+ * @internal Dequeue several objects from the ring
+ */
+static __rte_always_inline unsigned int
+__RTE_RING_CONCAT(__rte_ring_do_dequeue)(struct rte_ring *r,
+	RTE_RING_TMPLT_ELEM_TYPE *obj_table, unsigned int n,
+	enum rte_ring_queue_behavior behavior, unsigned int is_sc,
+	unsigned int *available)
+{
+	uint32_t cons_head, cons_next;
+	uint32_t entries;
+
+	n = __rte_ring_move_cons_head(r, (int)is_sc, n, behavior,
+			&cons_head, &cons_next, &entries);
+	if (n == 0)
+		goto end;
+
+	DEQUEUE_PTRS(r, &r[1], cons_head, obj_table, n,
+		RTE_RING_TMPLT_ELEM_TYPE);
+
+	update_tail(&r->cons, cons_head, cons_next, is_sc, 0);
+
+end:
+	if (available != NULL)
+		*available = entries - n;
+	return n;
+}
+
+
+/**
+ * Enqueue several objects on the ring (multi-producers safe).
+ */
+static __rte_always_inline unsigned int
+__RTE_RING_CONCAT(rte_ring_mp_enqueue_bulk)(struct rte_ring *r,
+	RTE_RING_TMPLT_ELEM_TYPE const *obj_table, unsigned int n,
+	unsigned int *free_space)
+{
+	return __RTE_RING_CONCAT(__rte_ring_do_enqueue)(r, obj_table, n,
+			RTE_RING_QUEUE_FIXED, __IS_MP, free_space);
+}
+
+/**
+ * Enqueue several objects on a ring (NOT multi-producers safe).
+ */
+static __rte_always_inline unsigned int
+__RTE_RING_CONCAT(rte_ring_sp_enqueue_bulk)(struct rte_ring *r,
+	RTE_RING_TMPLT_ELEM_TYPE const *obj_table, unsigned int n,
+	unsigned int *free_space)
+{
+	return __RTE_RING_CONCAT(__rte_ring_do_enqueue)(r, obj_table, n,
+			RTE_RING_QUEUE_FIXED, __IS_SP, free_space);
+}
+
+/**
+ * Enqueue several objects on a ring.
+ */
+static __rte_always_inline unsigned int
+__RTE_RING_CONCAT(rte_ring_enqueue_bulk)(struct rte_ring *r,
+	RTE_RING_TMPLT_ELEM_TYPE const *obj_table, unsigned int n,
+	unsigned int *free_space)
+{
+	return __RTE_RING_CONCAT(__rte_ring_do_enqueue)(r, obj_table, n,
+			RTE_RING_QUEUE_FIXED, r->prod.single, free_space);
+}
+
+/**
+ * Enqueue one object on a ring (multi-producers safe).
+ */
+static __rte_always_inline int
+__RTE_RING_CONCAT(rte_ring_mp_enqueue)(struct rte_ring *r,
+	RTE_RING_TMPLT_ELEM_TYPE const obj)
+{
+	return __RTE_RING_CONCAT(rte_ring_mp_enqueue_bulk)(r, &obj, 1, NULL) ?
+			0 : -ENOBUFS;
+}
+
+/**
+ * Enqueue one object on a ring (NOT multi-producers safe).
+ */
+static __rte_always_inline int
+__RTE_RING_CONCAT(rte_ring_sp_enqueue)(struct rte_ring *r,
+	RTE_RING_TMPLT_ELEM_TYPE const obj)
+{
+	return __RTE_RING_CONCAT(rte_ring_sp_enqueue_bulk)(r, &obj, 1, NULL) ?
+			0 : -ENOBUFS;
+}
+
+/**
+ * Enqueue one object on a ring.
+ */
+static __rte_always_inline int
+__RTE_RING_CONCAT(rte_ring_enqueue)(struct rte_ring *r,
+	RTE_RING_TMPLT_ELEM_TYPE const *obj)
+{
+	return __RTE_RING_CONCAT(rte_ring_enqueue_bulk)(r, obj, 1, NULL) ?
+			0 : -ENOBUFS;
+}
+
+/**
+ * Dequeue several objects from a ring (multi-consumers safe).
+ */
+static __rte_always_inline unsigned int
+__RTE_RING_CONCAT(rte_ring_mc_dequeue_bulk)(struct rte_ring *r,
+	RTE_RING_TMPLT_ELEM_TYPE *obj_table, unsigned int n,
+	unsigned int *available)
+{
+	return __RTE_RING_CONCAT(__rte_ring_do_dequeue)(r, obj_table, n,
+			RTE_RING_QUEUE_FIXED, __IS_MC, available);
+}
+
+/**
+ * Dequeue several objects from a ring (NOT multi-consumers safe).
+ */
+static __rte_always_inline unsigned int
+__RTE_RING_CONCAT(rte_ring_sc_dequeue_bulk)(struct rte_ring *r,
+	RTE_RING_TMPLT_ELEM_TYPE *obj_table, unsigned int n,
+	unsigned int *available)
+{
+	return __RTE_RING_CONCAT(__rte_ring_do_dequeue)(r, obj_table, n,
+			RTE_RING_QUEUE_FIXED, __IS_SC, available);
+}
+
+/**
+ * Dequeue several objects from a ring.
+ */
+static __rte_always_inline unsigned int
+__RTE_RING_CONCAT(rte_ring_dequeue_bulk)(struct rte_ring *r,
+	RTE_RING_TMPLT_ELEM_TYPE *obj_table, unsigned int n,
+	unsigned int *available)
+{
+	return __RTE_RING_CONCAT(__rte_ring_do_dequeue)(r, obj_table, n,
+			RTE_RING_QUEUE_FIXED, r->cons.single, available);
+}
+
+/**
+ * Dequeue one object from a ring (multi-consumers safe).
+ */
+static __rte_always_inline int
+__RTE_RING_CONCAT(rte_ring_mc_dequeue)(struct rte_ring *r,
+	RTE_RING_TMPLT_ELEM_TYPE *obj_p)
+{
+	return __RTE_RING_CONCAT(rte_ring_mc_dequeue_bulk)(r, obj_p, 1, NULL) ?
+			0 : -ENOENT;
+}
+
+/**
+ * Dequeue one object from a ring (NOT multi-consumers safe).
+ */
+static __rte_always_inline int
+__RTE_RING_CONCAT(rte_ring_sc_dequeue)(struct rte_ring *r,
+	RTE_RING_TMPLT_ELEM_TYPE *obj_p)
+{
+	return __RTE_RING_CONCAT(rte_ring_sc_dequeue_bulk)(r, obj_p, 1, NULL) ?
+			0 : -ENOENT;
+}
+
+/**
+ * Dequeue one object from a ring.
+ */
+static __rte_always_inline int
+__RTE_RING_CONCAT(rte_ring_dequeue)(struct rte_ring *r,
+	RTE_RING_TMPLT_ELEM_TYPE *obj_p)
+{
+	return __RTE_RING_CONCAT(rte_ring_dequeue_bulk)(r, obj_p, 1, NULL) ?
+			0 : -ENOENT;
+}
+
+/**
+ * Enqueue several objects on the ring (multi-producers safe).
+ */
+static __rte_always_inline unsigned
+__RTE_RING_CONCAT(rte_ring_mp_enqueue_burst)(struct rte_ring *r,
+	RTE_RING_TMPLT_ELEM_TYPE *obj_table,
+			 unsigned int n, unsigned int *free_space)
+{
+	return __RTE_RING_CONCAT(__rte_ring_do_enqueue)(r, obj_table, n,
+			RTE_RING_QUEUE_VARIABLE, __IS_MP, free_space);
+}
+
+/**
+ * Enqueue several objects on a ring (NOT multi-producers safe).
+ */
+static __rte_always_inline unsigned
+__RTE_RING_CONCAT(rte_ring_sp_enqueue_burst)(struct rte_ring *r,
+	RTE_RING_TMPLT_ELEM_TYPE *obj_table,
+			 unsigned int n, unsigned int *free_space)
+{
+	return __RTE_RING_CONCAT(__rte_ring_do_enqueue)(r, obj_table, n,
+			RTE_RING_QUEUE_VARIABLE, __IS_SP, free_space);
+}
+
+/**
+ * Enqueue several objects on a ring.
+ */
+static __rte_always_inline unsigned
+__RTE_RING_CONCAT(rte_ring_enqueue_burst)(struct rte_ring *r,
+	RTE_RING_TMPLT_ELEM_TYPE const *obj_table, unsigned int n,
+	unsigned int *free_space)
+{
+	return __RTE_RING_CONCAT(__rte_ring_do_enqueue)(r, obj_table, n,
+			RTE_RING_QUEUE_VARIABLE, r->prod.single, free_space);
+}
+
+/**
+ * Dequeue several objects from a ring (multi-consumers safe). When the request
+ * objects are more than the available objects, only dequeue the actual number
+ * of objects
+ */
+static __rte_always_inline unsigned
+__RTE_RING_CONCAT(rte_ring_mc_dequeue_burst)(struct rte_ring *r,
+	RTE_RING_TMPLT_ELEM_TYPE *obj_table, unsigned int n,
+	unsigned int *available)
+{
+	return __RTE_RING_CONCAT(__rte_ring_do_dequeue)(r, obj_table, n,
+			RTE_RING_QUEUE_VARIABLE, __IS_MC, available);
+}
+
+/**
+ * Dequeue several objects from a ring (NOT multi-consumers safe).When the
+ * request objects are more than the available objects, only dequeue the
+ * actual number of objects
+ */
+static __rte_always_inline unsigned
+__RTE_RING_CONCAT(rte_ring_sc_dequeue_burst)(struct rte_ring *r,
+	RTE_RING_TMPLT_ELEM_TYPE *obj_table, unsigned int n,
+	unsigned int *available)
+{
+	return __RTE_RING_CONCAT(__rte_ring_do_dequeue)(r, obj_table, n,
+			RTE_RING_QUEUE_VARIABLE, __IS_SC, available);
+}
+
+/**
+ * Dequeue multiple objects from a ring up to a maximum number.
+ */
+static __rte_always_inline unsigned
+__RTE_RING_CONCAT(rte_ring_dequeue_burst)(struct rte_ring *r,
+	RTE_RING_TMPLT_ELEM_TYPE *obj_table, unsigned int n,
+	unsigned int *available)
+{
+	return __RTE_RING_CONCAT(__rte_ring_do_dequeue)(r, obj_table, n,
+				RTE_RING_QUEUE_VARIABLE,
+				r->cons.single, available);
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _RTE_RING_TEMPLATE_H_ */