+++ /dev/null
-#ifndef _LINUX_RING_BUFFER_CONFIG_H
-#define _LINUX_RING_BUFFER_CONFIG_H
-
-/*
- * linux/ringbuffer/config.h
- *
- * Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * Ring buffer configuration header. Note: after declaring the standard inline
- * functions, clients should also include linux/ringbuffer/api.h.
- *
- * Dual LGPL v2.1/GPL v2 license.
- */
-
-#include <errno.h>
-#include "ust/lttng-tracer.h"
-#include "ust/usterr-signal-safe.h"
-#include "ust/kcompat/kcompat.h"
-#include "ust/align.h"
-
-struct lttng_ust_lib_ring_buffer;
-struct channel;
-struct lttng_ust_lib_ring_buffer_config;
-struct lttng_ust_lib_ring_buffer_ctx;
-struct lttng_ust_shm_handle *handle;
-
-/*
- * Ring buffer client callbacks. Only used by slow path, never on fast path.
- * For the fast path, record_header_size(), ring_buffer_clock_read() should be
- * provided as inline functions too. These may simply return 0 if not used by
- * the client.
- */
-struct lttng_ust_lib_ring_buffer_client_cb {
- /* Mandatory callbacks */
-
- /* A static inline version is also required for fast path */
- u64 (*ring_buffer_clock_read) (struct channel *chan);
- size_t (*record_header_size) (const struct lttng_ust_lib_ring_buffer_config *config,
- struct channel *chan, size_t offset,
- size_t *pre_header_padding,
- struct lttng_ust_lib_ring_buffer_ctx *ctx);
-
- /* Slow path only, at subbuffer switch */
- size_t (*subbuffer_header_size) (void);
- void (*buffer_begin) (struct lttng_ust_lib_ring_buffer *buf, u64 tsc,
- unsigned int subbuf_idx,
- struct lttng_ust_shm_handle *handle);
- void (*buffer_end) (struct lttng_ust_lib_ring_buffer *buf, u64 tsc,
- unsigned int subbuf_idx, unsigned long data_size,
- struct lttng_ust_shm_handle *handle);
-
- /* Optional callbacks (can be set to NULL) */
-
- /* Called at buffer creation/finalize */
- int (*buffer_create) (struct lttng_ust_lib_ring_buffer *buf, void *priv,
- int cpu, const char *name,
- struct lttng_ust_shm_handle *handle);
- /*
- * Clients should guarantee that no new reader handle can be opened
- * after finalize.
- */
- void (*buffer_finalize) (struct lttng_ust_lib_ring_buffer *buf,
- void *priv, int cpu,
- struct lttng_ust_shm_handle *handle);
-
- /*
- * Extract header length, payload length and timestamp from event
- * record. Used by buffer iterators. Timestamp is only used by channel
- * iterator.
- */
- void (*record_get) (const struct lttng_ust_lib_ring_buffer_config *config,
- struct channel *chan, struct lttng_ust_lib_ring_buffer *buf,
- size_t offset, size_t *header_len,
- size_t *payload_len, u64 *timestamp,
- struct lttng_ust_shm_handle *handle);
-};
-
-/*
- * Ring buffer instance configuration.
- *
- * Declare as "static const" within the client object to ensure the inline fast
- * paths can be optimized.
- *
- * alloc/sync pairs:
- *
- * RING_BUFFER_ALLOC_PER_CPU and RING_BUFFER_SYNC_PER_CPU :
- * Per-cpu buffers with per-cpu synchronization. Tracing must be performed
- * with preemption disabled (lib_ring_buffer_get_cpu() and
- * lib_ring_buffer_put_cpu()).
- *
- * RING_BUFFER_ALLOC_PER_CPU and RING_BUFFER_SYNC_GLOBAL :
- * Per-cpu buffer with global synchronization. Tracing can be performed with
- * preemption enabled, statistically stays on the local buffers.
- *
- * RING_BUFFER_ALLOC_GLOBAL and RING_BUFFER_SYNC_PER_CPU :
- * Should only be used for buffers belonging to a single thread or protected
- * by mutual exclusion by the client. Note that periodical sub-buffer switch
- * should be disabled in this kind of configuration.
- *
- * RING_BUFFER_ALLOC_GLOBAL and RING_BUFFER_SYNC_GLOBAL :
- * Global shared buffer with global synchronization.
- *
- * wakeup:
- *
- * RING_BUFFER_WAKEUP_BY_TIMER uses per-cpu deferrable timers to poll the
- * buffers and wake up readers if data is ready. Mainly useful for tracers which
- * don't want to call into the wakeup code on the tracing path. Use in
- * combination with "read_timer_interval" channel_create() argument.
- *
- * RING_BUFFER_WAKEUP_BY_WRITER directly wakes up readers when a subbuffer is
- * ready to read. Lower latencies before the reader is woken up. Mainly suitable
- * for drivers.
- *
- * RING_BUFFER_WAKEUP_NONE does not perform any wakeup whatsoever. The client
- * has the responsibility to perform wakeups.
- */
-struct lttng_ust_lib_ring_buffer_config {
- enum {
- RING_BUFFER_ALLOC_PER_CPU,
- RING_BUFFER_ALLOC_GLOBAL,
- } alloc;
- enum {
- RING_BUFFER_SYNC_PER_CPU, /* Wait-free */
- RING_BUFFER_SYNC_GLOBAL, /* Lock-free */
- } sync;
- enum {
- RING_BUFFER_OVERWRITE, /* Overwrite when buffer full */
- RING_BUFFER_DISCARD, /* Discard when buffer full */
- } mode;
- enum {
- RING_BUFFER_SPLICE,
- RING_BUFFER_MMAP,
- RING_BUFFER_READ, /* TODO */
- RING_BUFFER_ITERATOR,
- RING_BUFFER_NONE,
- } output;
- enum {
- RING_BUFFER_PAGE,
- RING_BUFFER_VMAP, /* TODO */
- RING_BUFFER_STATIC, /* TODO */
- } backend;
- enum {
- RING_BUFFER_NO_OOPS_CONSISTENCY,
- RING_BUFFER_OOPS_CONSISTENCY,
- } oops;
- enum {
- RING_BUFFER_IPI_BARRIER,
- RING_BUFFER_NO_IPI_BARRIER,
- } ipi;
- enum {
- RING_BUFFER_WAKEUP_BY_TIMER, /* wake up performed by timer */
- RING_BUFFER_WAKEUP_BY_WRITER, /*
- * writer wakes up reader,
- * not lock-free
- * (takes spinlock).
- */
- } wakeup;
- /*
- * tsc_bits: timestamp bits saved at each record.
- * 0 and 64 disable the timestamp compression scheme.
- */
- unsigned int tsc_bits;
- struct lttng_ust_lib_ring_buffer_client_cb cb;
-};
-
-/*
- * ring buffer context
- *
- * Context passed to lib_ring_buffer_reserve(), lib_ring_buffer_commit(),
- * lib_ring_buffer_try_discard_reserve(), lib_ring_buffer_align_ctx() and
- * lib_ring_buffer_write().
- */
-struct lttng_ust_lib_ring_buffer_ctx {
- /* input received by lib_ring_buffer_reserve(), saved here. */
- struct channel *chan; /* channel */
- void *priv; /* client private data */
- struct lttng_ust_shm_handle *handle; /* shared-memory handle */
- size_t data_size; /* size of payload */
- int largest_align; /*
- * alignment of the largest element
- * in the payload
- */
- int cpu; /* processor id */
-
- /* output from lib_ring_buffer_reserve() */
- struct lttng_ust_lib_ring_buffer *buf; /*
- * buffer corresponding to processor id
- * for this channel
- */
- size_t slot_size; /* size of the reserved slot */
- unsigned long buf_offset; /* offset following the record header */
- unsigned long pre_offset; /*
- * Initial offset position _before_
- * the record is written. Positioned
- * prior to record header alignment
- * padding.
- */
- u64 tsc; /* time-stamp counter value */
- unsigned int rflags; /* reservation flags */
-};
-
-/**
- * lib_ring_buffer_ctx_init - initialize ring buffer context
- * @ctx: ring buffer context to initialize
- * @chan: channel
- * @priv: client private data
- * @data_size: size of record data payload
- * @largest_align: largest alignment within data payload types
- * @cpu: processor id
- */
-static inline
-void lib_ring_buffer_ctx_init(struct lttng_ust_lib_ring_buffer_ctx *ctx,
- struct channel *chan, void *priv,
- size_t data_size, int largest_align,
- int cpu, struct lttng_ust_shm_handle *handle)
-{
- ctx->chan = chan;
- ctx->priv = priv;
- ctx->data_size = data_size;
- ctx->largest_align = largest_align;
- ctx->cpu = cpu;
- ctx->rflags = 0;
- ctx->handle = handle;
-}
-
-/*
- * Reservation flags.
- *
- * RING_BUFFER_RFLAG_FULL_TSC
- *
- * This flag is passed to record_header_size() and to the primitive used to
- * write the record header. It indicates that the full 64-bit time value is
- * needed in the record header. If this flag is not set, the record header needs
- * only to contain "tsc_bits" bit of time value.
- *
- * Reservation flags can be added by the client, starting from
- * "(RING_BUFFER_FLAGS_END << 0)". It can be used to pass information from
- * record_header_size() to lib_ring_buffer_write_record_header().
- */
-#define RING_BUFFER_RFLAG_FULL_TSC (1U << 0)
-#define RING_BUFFER_RFLAG_END (1U << 1)
-
-/*
- * We need to define RING_BUFFER_ALIGN_ATTR so it is known early at
- * compile-time. We have to duplicate the "config->align" information and the
- * definition here because config->align is used both in the slow and fast
- * paths, but RING_BUFFER_ALIGN_ATTR is only available for the client code.
- */
-#ifdef RING_BUFFER_ALIGN
-
-# define RING_BUFFER_ALIGN_ATTR /* Default arch alignment */
-
-/*
- * Calculate the offset needed to align the type.
- * size_of_type must be non-zero.
- */
-static inline
-unsigned int lib_ring_buffer_align(size_t align_drift, size_t size_of_type)
-{
- return offset_align(align_drift, size_of_type);
-}
-
-#else
-
-# define RING_BUFFER_ALIGN_ATTR __attribute__((packed))
-
-/*
- * Calculate the offset needed to align the type.
- * size_of_type must be non-zero.
- */
-static inline
-unsigned int lib_ring_buffer_align(size_t align_drift, size_t size_of_type)
-{
- return 0;
-}
-
-#endif
-
-/**
- * lib_ring_buffer_align_ctx - Align context offset on "alignment"
- * @ctx: ring buffer context.
- */
-static inline
-void lib_ring_buffer_align_ctx(struct lttng_ust_lib_ring_buffer_ctx *ctx,
- size_t alignment)
-{
- ctx->buf_offset += lib_ring_buffer_align(ctx->buf_offset,
- alignment);
-}
-
-/*
- * lib_ring_buffer_check_config() returns 0 on success.
- * Used internally to check for valid configurations at channel creation.
- */
-static inline
-int lib_ring_buffer_check_config(const struct lttng_ust_lib_ring_buffer_config *config,
- unsigned int switch_timer_interval,
- unsigned int read_timer_interval)
-{
- if (config->alloc == RING_BUFFER_ALLOC_GLOBAL
- && config->sync == RING_BUFFER_SYNC_PER_CPU
- && switch_timer_interval)
- return -EINVAL;
- return 0;
-}
-
-#include <ust/vatomic.h>
-
-#endif /* _LINUX_RING_BUFFER_CONFIG_H */
projects / ust.git / blobdiff