+++ /dev/null
-#ifndef _LIB_RING_BUFFER_FRONTEND_TYPES_H
-#define _LIB_RING_BUFFER_FRONTEND_TYPES_H
-
-/*
- * lib/ringbuffer/frontend_types.h
- *
- * Ring Buffer Library Synchronization Header (types).
- *
- * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; only
- * version 2.1 of the License.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
- * Author:
- * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * See ring_buffer_frontend.c for more information on wait-free algorithms.
- */
-
-#include <linux/kref.h>
-#include <wrapper/ringbuffer/config.h>
-#include <wrapper/ringbuffer/backend_types.h>
-#include <wrapper/spinlock.h>
-#include <lib/prio_heap/lttng_prio_heap.h> /* For per-CPU read-side iterator */
-
-/*
- * A switch is done during tracing or as a final flush after tracing (so it
- * won't write in the new sub-buffer).
- */
-enum switch_mode { SWITCH_ACTIVE, SWITCH_FLUSH };
-
-/* channel-level read-side iterator */
-struct channel_iter {
- /* Prio heap of buffers. Lowest timestamps at the top. */
- struct lttng_ptr_heap heap; /* Heap of struct lib_ring_buffer ptrs */
- struct list_head empty_head; /* Empty buffers linked-list head */
- int read_open; /* Opened for reading ? */
- u64 last_qs; /* Last quiescent state timestamp */
- u64 last_timestamp; /* Last timestamp (for WARN_ON) */
- int last_cpu; /* Last timestamp cpu */
- /*
- * read() file operation state.
- */
- unsigned long len_left;
-};
-
-/* channel: collection of per-cpu ring buffers. */
-struct channel {
- atomic_t record_disabled;
- unsigned long commit_count_mask; /*
- * Commit count mask, removing
- * the MSBs corresponding to
- * bits used to represent the
- * subbuffer index.
- */
-
- struct channel_backend backend; /* Associated backend */
-
- unsigned long switch_timer_interval; /* Buffer flush (jiffies) */
- unsigned long read_timer_interval; /* Reader wakeup (jiffies) */
- struct notifier_block cpu_hp_notifier; /* CPU hotplug notifier */
- struct notifier_block tick_nohz_notifier; /* CPU nohz notifier */
- struct notifier_block hp_iter_notifier; /* hotplug iterator notifier */
- unsigned int cpu_hp_enable:1; /* Enable CPU hotplug notif. */
- unsigned int hp_iter_enable:1; /* Enable hp iter notif. */
- wait_queue_head_t read_wait; /* reader wait queue */
- wait_queue_head_t hp_wait; /* CPU hotplug wait queue */
- int finalized; /* Has channel been finalized */
- struct channel_iter iter; /* Channel read-side iterator */
- struct kref ref; /* Reference count */
-};
-
-/* Per-subbuffer commit counters used on the hot path */
-struct commit_counters_hot {
- union v_atomic cc; /* Commit counter */
- union v_atomic seq; /* Consecutive commits */
-};
-
-/* Per-subbuffer commit counters used only on cold paths */
-struct commit_counters_cold {
- union v_atomic cc_sb; /* Incremented _once_ at sb switch */
-};
-
-/* Per-buffer read iterator */
-struct lib_ring_buffer_iter {
- u64 timestamp; /* Current record timestamp */
- size_t header_len; /* Current record header length */
- size_t payload_len; /* Current record payload length */
-
- struct list_head empty_node; /* Linked list of empty buffers */
- unsigned long consumed, read_offset, data_size;
- enum {
- ITER_GET_SUBBUF = 0,
- ITER_TEST_RECORD,
- ITER_NEXT_RECORD,
- ITER_PUT_SUBBUF,
- } state;
- unsigned int allocated:1;
- unsigned int read_open:1; /* Opened for reading ? */
-};
-
-/* ring buffer state */
-struct lib_ring_buffer {
- /* First 32 bytes cache-hot cacheline */
- union v_atomic offset; /* Current offset in the buffer */
- struct commit_counters_hot *commit_hot;
- /* Commit count per sub-buffer */
- atomic_long_t consumed; /*
- * Current offset in the buffer
- * standard atomic access (shared)
- */
- atomic_t record_disabled;
- /* End of first 32 bytes cacheline */
- union v_atomic last_tsc; /*
- * Last timestamp written in the buffer.
- */
-
- struct lib_ring_buffer_backend backend; /* Associated backend */
-
- struct commit_counters_cold *commit_cold;
- /* Commit count per sub-buffer */
- atomic_long_t active_readers; /*
- * Active readers count
- * standard atomic access (shared)
- */
- /* Dropped records */
- union v_atomic records_lost_full; /* Buffer full */
- union v_atomic records_lost_wrap; /* Nested wrap-around */
- union v_atomic records_lost_big; /* Events too big */
- union v_atomic records_count; /* Number of records written */
- union v_atomic records_overrun; /* Number of overwritten records */
- wait_queue_head_t read_wait; /* reader buffer-level wait queue */
- wait_queue_head_t write_wait; /* writer buffer-level wait queue (for metadata only) */
- int finalized; /* buffer has been finalized */
- struct timer_list switch_timer; /* timer for periodical switch */
- struct timer_list read_timer; /* timer for read poll */
- raw_spinlock_t raw_tick_nohz_spinlock; /* nohz entry lock/trylock */
- struct lib_ring_buffer_iter iter; /* read-side iterator */
- unsigned long get_subbuf_consumed; /* Read-side consumed */
- unsigned long prod_snapshot; /* Producer count snapshot */
- unsigned long cons_snapshot; /* Consumer count snapshot */
- unsigned int get_subbuf:1, /* Sub-buffer being held by reader */
- switch_timer_enabled:1, /* Protected by ring_buffer_nohz_lock */
- read_timer_enabled:1; /* Protected by ring_buffer_nohz_lock */
-};
-
-static inline
-void *channel_get_private(struct channel *chan)
-{
- return chan->backend.priv;
-}
-
-void lib_ring_buffer_lost_event_too_big(struct channel *chan);
-
-/*
- * Issue warnings and disable channels upon internal error.
- * Can receive struct lib_ring_buffer or struct lib_ring_buffer_backend
- * parameters.
- */
-#define CHAN_WARN_ON(c, cond) \
- ({ \
- struct channel *__chan; \
- int _____ret = unlikely(cond); \
- if (_____ret) { \
- if (__same_type(*(c), struct channel_backend)) \
- __chan = container_of((void *) (c), \
- struct channel, \
- backend); \
- else if (__same_type(*(c), struct channel)) \
- __chan = (void *) (c); \
- else \
- BUG_ON(1); \
- atomic_inc(&__chan->record_disabled); \
- WARN_ON(1); \
- } \
- _____ret; \
- })
-
-#endif /* _LIB_RING_BUFFER_FRONTEND_TYPES_H */
projects / lttng-modules.git / blobdiff