diff options
Diffstat (limited to 'include/linux/relay.h')
| -rw-r--r-- | include/linux/relay.h | 85 |
1 files changed, 47 insertions, 38 deletions
diff --git a/include/linux/relay.h b/include/linux/relay.h index d7c8359693c6..6772a7075840 100644 --- a/include/linux/relay.h +++ b/include/linux/relay.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ /* * linux/include/linux/relay.h * @@ -15,10 +16,12 @@ #include <linux/timer.h> #include <linux/wait.h> #include <linux/list.h> +#include <linux/irq_work.h> #include <linux/bug.h> #include <linux/fs.h> #include <linux/poll.h> #include <linux/kref.h> +#include <linux/percpu.h> /* * Tracks changes to rchan/rchan_buf structs @@ -26,6 +29,22 @@ #define RELAYFS_CHANNEL_VERSION 7 /* + * Relay buffer statistics + */ +enum { + RELAY_STATS_BUF_FULL = (1 << 0), + RELAY_STATS_WRT_BIG = (1 << 1), + + RELAY_STATS_LAST = RELAY_STATS_WRT_BIG, +}; + +struct rchan_buf_stats +{ + unsigned int full_count; /* counter for buffer full */ + unsigned int big_count; /* counter for too big to write */ +}; + +/* * Per-cpu relay channel buffer */ struct rchan_buf @@ -37,14 +56,14 @@ struct rchan_buf size_t subbufs_consumed; /* count of sub-buffers consumed */ struct rchan *chan; /* associated channel */ wait_queue_head_t read_wait; /* reader wait queue */ - struct timer_list timer; /* reader wake-up timer */ + struct irq_work wakeup_work; /* reader wakeup */ struct dentry *dentry; /* channel file dentry */ struct kref kref; /* channel buffer refcount */ + struct rchan_buf_stats stats; /* buffer stats */ struct page **page_array; /* array of current buffer pages */ unsigned int page_count; /* number of current buffer pages */ unsigned int finalized; /* buffer has been finalized */ size_t *padding; /* padding counts per sub-buffer */ - size_t prev_padding; /* temporary variable */ size_t bytes_consumed; /* bytes consumed in cur read subbuf */ size_t early_bytes; /* bytes consumed before VFS inited */ unsigned int cpu; /* this buf's cpu */ @@ -59,11 +78,10 @@ struct rchan 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 */ + const struct rchan_callbacks *cb; /* client callbacks */ struct kref kref; /* channel refcount */ void *private_data; /* for user-defined data */ - size_t last_toobig; /* tried to log event > subbuf size */ - struct rchan_buf *buf[NR_CPUS]; /* per-cpu channel buffers */ + struct rchan_buf * __percpu *buf; /* per-cpu channel buffers */ int is_global; /* One global buffer ? */ struct list_head list; /* for channel list */ struct dentry *parent; /* parent dentry passed to open */ @@ -81,11 +99,12 @@ struct rchan_callbacks * @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. * + * This callback is optional. + * * 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. @@ -95,29 +114,9 @@ struct rchan_callbacks */ int (*subbuf_start) (struct rchan_buf *buf, void *subbuf, - void *prev_subbuf, - size_t prev_padding); + void *prev_subbuf); /* - * buf_mapped - relay buffer mmap notification - * @buf: the channel buffer - * @filp: relay file pointer - * - * Called when a relay file is successfully mmapped - */ - void (*buf_mapped)(struct rchan_buf *buf, - struct file *filp); - - /* - * buf_unmapped - relay buffer unmap notification - * @buf: the channel buffer - * @filp: relay file pointer - * - * Called when a relay file is successfully unmapped - */ - void (*buf_unmapped)(struct rchan_buf *buf, - struct file *filp); - /* * 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 @@ -138,7 +137,9 @@ struct rchan_callbacks * cause relay_open() to create a single global buffer rather * than the default set of per-cpu buffers. * - * See Documentation/filesystems/relay.txt for more info. + * This callback is mandatory. + * + * See Documentation/filesystems/relay.rst for more info. */ struct dentry *(*create_buf_file)(const char *filename, struct dentry *parent, @@ -155,6 +156,8 @@ struct rchan_callbacks * channel buffer. * * The callback should return 0 if successful, negative if not. + * + * This callback is mandatory. */ int (*remove_buf_file)(struct dentry *dentry); }; @@ -167,13 +170,11 @@ struct rchan *relay_open(const char *base_filename, struct dentry *parent, size_t subbuf_size, size_t n_subbufs, - struct rchan_callbacks *cb, + const struct rchan_callbacks *cb, void *private_data); -extern int relay_late_setup_files(struct rchan *chan, - const char *base_filename, - struct dentry *parent); extern void relay_close(struct rchan *chan); extern void relay_flush(struct rchan *chan); +size_t relay_stats(struct rchan *chan, int flags); extern void relay_subbufs_consumed(struct rchan *chan, unsigned int cpu, size_t consumed); @@ -204,7 +205,7 @@ static inline void relay_write(struct rchan *chan, struct rchan_buf *buf; local_irq_save(flags); - buf = chan->buf[smp_processor_id()]; + buf = *this_cpu_ptr(chan->buf); if (unlikely(buf->offset + length > chan->subbuf_size)) length = relay_switch_subbuf(buf, length); memcpy(buf->data + buf->offset, data, length); @@ -230,12 +231,12 @@ static inline void __relay_write(struct rchan *chan, { struct rchan_buf *buf; - buf = chan->buf[get_cpu()]; + buf = *get_cpu_ptr(chan->buf); if (unlikely(buf->offset + length > buf->chan->subbuf_size)) length = relay_switch_subbuf(buf, length); memcpy(buf->data + buf->offset, data, length); buf->offset += length; - put_cpu(); + put_cpu_ptr(chan->buf); } /** @@ -251,17 +252,19 @@ static inline void __relay_write(struct rchan *chan, */ static inline void *relay_reserve(struct rchan *chan, size_t length) { - void *reserved; - struct rchan_buf *buf = chan->buf[smp_processor_id()]; + void *reserved = NULL; + struct rchan_buf *buf = *get_cpu_ptr(chan->buf); if (unlikely(buf->offset + length > buf->chan->subbuf_size)) { length = relay_switch_subbuf(buf, length); if (!length) - return NULL; + goto end; } reserved = buf->data + buf->offset; buf->offset += length; +end: + put_cpu_ptr(chan->buf); return reserved; } @@ -285,5 +288,11 @@ static inline void subbuf_start_reserve(struct rchan_buf *buf, */ extern const struct file_operations relay_file_operations; +#ifdef CONFIG_RELAY +int relay_prepare_cpu(unsigned int cpu); +#else +#define relay_prepare_cpu NULL +#endif + #endif /* _LINUX_RELAY_H */ |