1 #ifndef _LIB_RING_BUFFER_BACKEND_TYPES_H
2 #define _LIB_RING_BUFFER_BACKEND_TYPES_H
5 * lib/ringbuffer/backend_types.h
7 * Ring buffer backend (types).
9 * Copyright (C) 2008-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
11 * This library is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU Lesser General Public
13 * License as published by the Free Software Foundation; only
14 * version 2.1 of the License.
16 * This library is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 * Lesser General Public License for more details.
21 * You should have received a copy of the GNU Lesser General Public
22 * License along with this library; if not, write to the Free Software
23 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26 #include <linux/cpumask.h>
27 #include <linux/types.h>
28 #include <lttng-kernel-version.h>
29 #include <lttng-cpuhotplug.h>
31 struct lib_ring_buffer_backend_page
{
32 void *virt
; /* page virtual address (cached) */
33 unsigned long pfn
; /* page frame number */
36 struct lib_ring_buffer_backend_pages
{
37 unsigned long mmap_offset
; /* offset of the subbuffer in mmap */
38 union v_atomic records_commit
; /* current records committed count */
39 union v_atomic records_unread
; /* records to read */
40 unsigned long data_size
; /* Amount of data to read from subbuf */
41 struct lib_ring_buffer_backend_page p
[];
44 struct lib_ring_buffer_backend_subbuffer
{
45 /* Identifier for subbuf backend pages. Exchanged atomically. */
46 unsigned long id
; /* backend subbuffer identifier */
49 struct lib_ring_buffer_backend_counts
{
51 * Counter specific to the sub-buffer location within the ring buffer.
52 * The actual sequence number of the packet within the entire ring
53 * buffer can be derived from the formula nr_subbuffers * seq_cnt +
56 uint64_t seq_cnt
; /* packet sequence number */
60 * Forward declaration of frontend-specific channel and ring_buffer.
63 struct lib_ring_buffer
;
65 struct lib_ring_buffer_backend
{
66 /* Array of ring_buffer_backend_subbuffer for writer */
67 struct lib_ring_buffer_backend_subbuffer
*buf_wsb
;
68 /* ring_buffer_backend_subbuffer for reader */
69 struct lib_ring_buffer_backend_subbuffer buf_rsb
;
70 /* Array of lib_ring_buffer_backend_counts for the packet counter */
71 struct lib_ring_buffer_backend_counts
*buf_cnt
;
73 * Pointer array of backend pages, for whole buffer.
74 * Indexed by ring_buffer_backend_subbuffer identifier (id) index.
76 struct lib_ring_buffer_backend_pages
**array
;
77 unsigned int num_pages_per_subbuf
;
79 struct channel
*chan
; /* Associated channel */
80 int cpu
; /* This buffer's cpu. -1 if global. */
81 union v_atomic records_read
; /* Number of records read */
82 unsigned int allocated
:1; /* is buffer allocated ? */
85 struct channel_backend
{
86 unsigned long buf_size
; /* Size of the buffer */
87 unsigned long subbuf_size
; /* Sub-buffer size */
88 unsigned int subbuf_size_order
; /* Order of sub-buffer size */
89 unsigned int num_subbuf_order
; /*
90 * Order of number of sub-buffers/buffer
93 unsigned int buf_size_order
; /* Order of buffer size */
94 unsigned int extra_reader_sb
:1; /* has extra reader subbuffer ? */
95 struct lib_ring_buffer
*buf
; /* Channel per-cpu buffers */
97 unsigned long num_subbuf
; /* Number of sub-buffers for writer */
98 u64 start_tsc
; /* Channel creation TSC value */
99 void *priv
; /* Client-specific information */
100 void *priv_ops
; /* Client-specific ops pointer */
101 void (*release_priv_ops
)(void *priv_ops
);
102 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
103 struct lttng_cpuhp_node cpuhp_prepare
; /* CPU hotplug prepare */
105 struct notifier_block cpu_hp_notifier
; /* CPU hotplug notifier */
108 * We need to copy config because the module containing the
109 * source config can vanish before the last reference to this
110 * channel's streams is released.
112 struct lib_ring_buffer_config config
; /* Ring buffer configuration */
113 cpumask_var_t cpumask
; /* Allocated per-cpu buffers cpumask */
114 char name
[NAME_MAX
]; /* Channel name */
117 #endif /* _LIB_RING_BUFFER_BACKEND_TYPES_H */