+++ /dev/null
-/*
- * linux/include/linux/ltt-relay.h
- *
- * Copyright (C) 2002, 2003 - Tom Zanussi (zanussi@us.ibm.com), IBM Corp
- * Copyright (C) 1999, 2000, 2001, 2002 - Karim Yaghmour (karim@opersys.com)
- * Copyright (C) 2008 - Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca)
- *
- * CONFIG_RELAY definitions and declarations
- */
-
-#ifndef _LINUX_LTT_RELAY_H
-#define _LINUX_LTT_RELAY_H
-
-//ust// #include <linux/types.h>
-//ust// #include <linux/sched.h>
-//ust// #include <linux/timer.h>
-//ust// #include <linux/wait.h>
-//ust// #include <linux/list.h>
-//ust// #include <linux/fs.h>
-//ust// #include <linux/poll.h>
-//ust// #include <linux/kref.h>
-//ust// #include <linux/mm.h>
-//ust// #include <linux/ltt-core.h>
-#include "kref.h"
-#include "list.h"
-
-/* Needs a _much_ better name... */
-#define FIX_SIZE(x) ((((x) - 1) & PAGE_MASK) + PAGE_SIZE)
-
-/*
- * Tracks changes to rchan/rchan_buf structs
- */
-#define LTT_RELAY_CHANNEL_VERSION 8
-
-struct rchan_buf;
-
-struct buf_page {
- struct page *page;
- struct rchan_buf *buf; /* buffer the page belongs to */
- size_t offset; /* page offset in the buffer */
- struct list_head list; /* buffer linked list */
-};
-
-/*
- * Per-cpu relay channel buffer
- */
-struct rchan_buf {
- struct rchan *chan; /* associated channel */
-//ust// wait_queue_head_t read_wait; /* reader wait queue */
-//ust// struct timer_list timer; /* reader wake-up timer */
-//ust// struct dentry *dentry; /* channel file dentry */
- struct kref kref; /* channel buffer refcount */
-//ust// struct list_head pages; /* list of buffer pages */
- void *buf_data; //ust//
- size_t buf_size;
-//ust// struct buf_page *wpage; /* current write page (cache) */
-//ust// struct buf_page *hpage[2]; /* current subbuf header page (cache) */
-//ust// struct buf_page *rpage; /* current subbuf read page (cache) */
-//ust// unsigned int page_count; /* number of current buffer pages */
- unsigned int finalized; /* buffer has been finalized */
-//ust// unsigned int cpu; /* this buf's cpu */
- int shmid; /* the shmid of the buffer data pages */
-} ____cacheline_aligned;
-
-/*
- * Relay channel data structure
- */
-struct rchan {
- u32 version; /* the version of this struct */
- size_t subbuf_size; /* sub-buffer size */
- size_t n_subbufs; /* number of sub-buffers per buffer */
- size_t alloc_size; /* total buffer size allocated */
- struct rchan_callbacks *cb; /* client callbacks */
- struct kref kref; /* channel refcount */
- void *private_data; /* for user-defined data */
-//ust// struct rchan_buf *buf[NR_CPUS]; /* per-cpu channel buffers */
- struct rchan_buf *buf;
- struct list_head list; /* for channel list */
- struct dentry *parent; /* parent dentry passed to open */
- int subbuf_size_order; /* order of sub-buffer size */
-//ust// char base_filename[NAME_MAX]; /* saved base filename */
-};
-
-/*
- * Relay channel client callbacks
- */
-struct rchan_callbacks {
- /*
- * subbuf_start - called on buffer-switch to a new sub-buffer
- * @buf: the channel buffer containing the new sub-buffer
- * @subbuf: the start of the new sub-buffer
- * @prev_subbuf: the start of the previous sub-buffer
- * @prev_padding: unused space at the end of previous sub-buffer
- *
- * The client should return 1 to continue logging, 0 to stop
- * logging.
- *
- * NOTE: subbuf_start will also be invoked when the buffer is
- * created, so that the first sub-buffer can be initialized
- * if necessary. In this case, prev_subbuf will be NULL.
- *
- * NOTE: the client can reserve bytes at the beginning of the new
- * sub-buffer by calling subbuf_start_reserve() in this callback.
- */
- int (*subbuf_start) (struct rchan_buf *buf,
- void *subbuf,
- void *prev_subbuf,
- size_t prev_padding);
-
- /*
- * create_buf_file - create file to represent a relay channel buffer
- * @filename: the name of the file to create
- * @parent: the parent of the file to create
- * @mode: the mode of the file to create
- * @buf: the channel buffer
- *
- * Called during relay_open(), once for each per-cpu buffer,
- * to allow the client to create a file to be used to
- * represent the corresponding channel buffer. If the file is
- * created outside of relay, the parent must also exist in
- * that filesystem.
- *
- * The callback should return the dentry of the file created
- * to represent the relay buffer.
- *
- * Setting the is_global outparam to a non-zero value will
- * cause relay_open() to create a single global buffer rather
- * than the default set of per-cpu buffers.
- *
- * See Documentation/filesystems/relayfs.txt for more info.
- */
- struct dentry *(*create_buf_file)(const char *filename,
- struct dentry *parent,
- int mode,
- struct rchan_buf *buf);
-
- /*
- * remove_buf_file - remove file representing a relay channel buffer
- * @dentry: the dentry of the file to remove
- *
- * Called during relay_close(), once for each per-cpu buffer,
- * to allow the client to remove a file used to represent a
- * channel buffer.
- *
- * The callback should return 0 if successful, negative if not.
- */
-//ust// int (*remove_buf_file)(struct rchan_buf *buf);
-};
-
-extern struct buf_page *ltt_relay_find_prev_page(struct rchan_buf *buf,
- struct buf_page *page, size_t offset, ssize_t diff_offset);
-
-extern struct buf_page *ltt_relay_find_next_page(struct rchan_buf *buf,
- struct buf_page *page, size_t offset, ssize_t diff_offset);
-
-extern void _ltt_relay_write(struct rchan_buf *buf, size_t offset,
- const void *src, size_t len, ssize_t cpy);
-
-extern int ltt_relay_read(struct rchan_buf *buf, size_t offset,
- void *dest, size_t len);
-
-extern struct buf_page *ltt_relay_read_get_page(struct rchan_buf *buf,
- size_t offset);
-
-/*
- * Return the address where a given offset is located.
- * Should be used to get the current subbuffer header pointer. Given we know
- * it's never on a page boundary, it's safe to write directly to this address,
- * as long as the write is never bigger than a page size.
- */
-extern void *ltt_relay_offset_address(struct rchan_buf *buf,
- size_t offset);
-
-/*
- * Find the page containing "offset". Cache it if it is after the currently
- * cached page.
- */
-static inline struct buf_page *ltt_relay_cache_page(struct rchan_buf *buf,
- struct buf_page **page_cache,
- struct buf_page *page, size_t offset)
-{
- ssize_t diff_offset;
- ssize_t half_buf_size = buf->chan->alloc_size >> 1;
-
- /*
- * Make sure this is the page we want to write into. The current
- * page is changed concurrently by other writers. [wrh]page are
- * used as a cache remembering the last page written
- * to/read/looked up for header address. No synchronization;
- * could have to find the previous page is a nested write
- * occured. Finding the right page is done by comparing the
- * dest_offset with the buf_page offsets.
- * When at the exact opposite of the buffer, bias towards forward search
- * because it will be cached.
- */
-
- diff_offset = (ssize_t)offset - (ssize_t)page->offset;
- if (diff_offset <= -(ssize_t)half_buf_size)
- diff_offset += buf->chan->alloc_size;
- else if (diff_offset > half_buf_size)
- diff_offset -= buf->chan->alloc_size;
-
- if (unlikely(diff_offset >= (ssize_t)PAGE_SIZE)) {
- page = ltt_relay_find_next_page(buf, page, offset, diff_offset);
- *page_cache = page;
- } else if (unlikely(diff_offset < 0)) {
- page = ltt_relay_find_prev_page(buf, page, offset, diff_offset);
- }
- return page;
-}
-
-//ust// #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
- static inline void ltt_relay_do_copy(void *dest, const void *src, size_t len)
-{
- switch (len) {
- case 0: break;
- case 1: *(u8 *)dest = *(const u8 *)src;
- break;
- case 2: *(u16 *)dest = *(const u16 *)src;
- break;
- case 4: *(u32 *)dest = *(const u32 *)src;
- break;
-//ust// #if (BITS_PER_LONG == 64)
- case 8: *(u64 *)dest = *(const u64 *)src;
- break;
-//ust// #endif
- default:
- memcpy(dest, src, len);
- }
-}
-//ust// #else
-//ust// /*
-//ust// * Returns whether the dest and src addresses are aligned on
-//ust// * min(sizeof(void *), len). Call this with statically known len for efficiency.
-//ust// */
-//ust// static inline int addr_aligned(const void *dest, const void *src, size_t len)
-//ust// {
-//ust// if (ltt_align((size_t)dest, len))
-//ust// return 0;
-//ust// if (ltt_align((size_t)src, len))
-//ust// return 0;
-//ust// return 1;
-//ust// }
-//ust//
-//ust// static inline void ltt_relay_do_copy(void *dest, const void *src, size_t len)
-//ust// {
-//ust// switch (len) {
-//ust// case 0: break;
-//ust// case 1: *(u8 *)dest = *(const u8 *)src;
-//ust// break;
-//ust// case 2: if (unlikely(!addr_aligned(dest, src, 2)))
-//ust// goto memcpy_fallback;
-//ust// *(u16 *)dest = *(const u16 *)src;
-//ust// break;
-//ust// case 4: if (unlikely(!addr_aligned(dest, src, 4)))
-//ust// goto memcpy_fallback;
-//ust// *(u32 *)dest = *(const u32 *)src;
-//ust// break;
-//ust// #if (BITS_PER_LONG == 64)
-//ust// case 8: if (unlikely(!addr_aligned(dest, src, 8)))
-//ust// goto memcpy_fallback;
-//ust// *(u64 *)dest = *(const u64 *)src;
-//ust// break;
-//ust// #endif
-//ust// default:
-//ust// goto memcpy_fallback;
-//ust// }
-//ust// return;
-//ust// memcpy_fallback:
-//ust// memcpy(dest, src, len);
-//ust// }
-//ust// #endif
-
-static inline int ltt_relay_write(struct rchan_buf *buf, size_t offset,
- const void *src, size_t len)
-{
-//ust// struct buf_page *page;
-//ust// ssize_t pagecpy;
-//ust//
-//ust// offset &= buf->chan->alloc_size - 1;
-//ust// page = buf->wpage;
-//ust//
-//ust// page = ltt_relay_cache_page(buf, &buf->wpage, page, offset);
-//ust// pagecpy = min_t(size_t, len, PAGE_SIZE - (offset & ~PAGE_MASK));
-//ust// ltt_relay_do_copy(page_address(page->page)
-//ust// + (offset & ~PAGE_MASK), src, pagecpy);
-//ust//
-//ust// if (unlikely(len != pagecpy))
-//ust// _ltt_relay_write(buf, offset, src, len, page, pagecpy);
-//ust// return len;
-
-
- size_t cpy;
- cpy = min_t(size_t, len, buf->buf_size - offset);
- ltt_relay_do_copy(buf->buf_data + offset, src, cpy);
-
- if (unlikely(len != cpy))
- _ltt_relay_write(buf, offset, src, len, cpy);
- return len;
-}
-
-/*
- * CONFIG_LTT_RELAY kernel API, ltt/ltt-relay-alloc.c
- */
-
-struct rchan *ltt_relay_open(const char *base_filename,
- struct dentry *parent,
- size_t subbuf_size,
- size_t n_subbufs,
- void *private_data);
-extern void ltt_relay_close(struct rchan *chan);
-
-/*
- * exported ltt_relay file operations, ltt/ltt-relay-alloc.c
- */
-extern const struct file_operations ltt_relay_file_operations;
-
-
-/* LTTng lockless logging buffer info */
-struct ltt_channel_buf_struct {
- /* First 32 bytes cache-hot cacheline */
- local_t offset; /* Current offset in the buffer */
-//ust// local_t *commit_count; /* Commit count per sub-buffer */
- atomic_long_t consumed; /*
- * Current offset in the buffer
- * standard atomic access (shared)
- */
- unsigned long last_tsc; /*
- * Last timestamp written in the buffer.
- */
- /* End of first 32 bytes cacheline */
- atomic_long_t active_readers; /*
- * Active readers count
- * standard atomic access (shared)
- */
- local_t events_lost;
- local_t corrupted_subbuffers;
-//ust// spinlock_t full_lock; /*
-//ust// * buffer full condition spinlock, only
-//ust// * for userspace tracing blocking mode
-//ust// * synchronization with reader.
-//ust// */
-//ust// wait_queue_head_t write_wait; /*
-//ust// * Wait queue for blocking user space
-//ust// * writers
-//ust// */
-//ust// atomic_t wakeup_readers; /* Boolean : wakeup readers waiting ? */
- /* one byte is written to this pipe when data is available, in order
- to wake the consumer */
- /* portability: Single byte writes must be as quick as possible. The kernel-side
- buffer must be large enough so the writer doesn't block. From the pipe(7)
- man page: Since linux 2.6.11, the pipe capacity is 65536 bytes. */
- int data_ready_fd_write;
- /* the reading end of the pipe */
- int data_ready_fd_read;
-
- /* commit count per subbuffer; must be at end of struct */
- local_t commit_count[0] ____cacheline_aligned;
-} ____cacheline_aligned;
-
-int ltt_do_get_subbuf(struct rchan_buf *buf, struct ltt_channel_buf_struct *ltt_buf, long *pconsumed_old);
-
-int ltt_do_put_subbuf(struct rchan_buf *buf, struct ltt_channel_buf_struct *ltt_buf, u32 uconsumed_old);
-
-
-#endif /* _LINUX_LTT_RELAY_H */
-
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