* Dual LGPL v2.1/GPL v2 license.
*/
+#define _GNU_SOURCE
#include <sys/types.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <urcu/compiler.h>
#include <urcu/ref.h>
+#include <helper.h>
#include "smp.h"
#include <lttng/ringbuffer-config.h>
+#include "vatomic.h"
#include "backend.h"
#include "frontend.h"
#include "shm.h"
+#include "tlsfixup.h"
#ifndef max
#define max(a, b) ((a) > (b) ? (a) : (b))
#endif
+/* Print DBG() messages about events lost only every 1048576 hits */
+#define DBG_PRINT_NR_LOST (1UL << 20)
+
/*
* Use POSIX SHM: shm_open(3) and shm_unlink(3).
* close(2) to close the fd returned by shm_open.
__thread unsigned int lib_ring_buffer_nesting;
+/*
+ * TODO: this is unused. Errors are saved within the ring buffer.
+ * Eventually, allow consumerd to print these errors.
+ */
static
void lib_ring_buffer_print_errors(struct channel *chan,
struct lttng_ust_lib_ring_buffer *buf, int cpu,
- struct lttng_ust_shm_handle *handle);
-
-/*
- * Must be called under cpu hotplug protection.
- */
-void lib_ring_buffer_free(struct lttng_ust_lib_ring_buffer *buf,
- struct lttng_ust_shm_handle *handle)
-{
- struct channel *chan = shmp(handle, buf->backend.chan);
-
- lib_ring_buffer_print_errors(chan, buf, buf->backend.cpu, handle);
- /* buf->commit_hot will be freed by shm teardown */
- /* buf->commit_cold will be freed by shm teardown */
-
- lib_ring_buffer_backend_free(&buf->backend);
-}
+ struct lttng_ust_shm_handle *handle)
+ __attribute__((unused));
/**
* lib_ring_buffer_reset - Reset ring buffer to initial values.
const struct lttng_ust_lib_ring_buffer_config *config = &chanb->config;
struct channel *chan = caa_container_of(chanb, struct channel, backend);
void *priv = channel_get_private(chan);
- unsigned int num_subbuf;
size_t subbuf_header_size;
- u64 tsc;
+ uint64_t tsc;
int ret;
/* Test for cpu hotplug */
goto free_commit;
}
- num_subbuf = chan->backend.num_subbuf;
- //init_waitqueue_head(&buf->read_wait);
-
/*
* Write the subbuffer header for first subbuffer so we know the total
* duration of data gathering.
free_commit:
/* commit_hot will be freed by shm teardown */
free_chanbuf:
- lib_ring_buffer_backend_free(&buf->backend);
return ret;
}
void *buf_addr, size_t subbuf_size,
size_t num_subbuf, unsigned int switch_timer_interval,
unsigned int read_timer_interval,
- int *shm_fd, int *wait_fd, uint64_t *memory_map_size)
+ int **shm_fd, int **wait_fd, uint64_t **memory_map_size)
{
int ret, cpu;
size_t shmsize, chansize;
void channel_destroy(struct channel *chan, struct lttng_ust_shm_handle *handle,
int shadow)
{
- const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
- int cpu;
-
if (shadow) {
channel_release(chan, handle, shadow);
return;
channel_unregister_notifiers(chan, handle);
- if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
- for_each_channel_cpu(cpu, chan) {
- struct lttng_ust_lib_ring_buffer *buf = shmp(handle, chan->backend.buf[cpu].shmp);
-
- if (config->cb.buffer_finalize)
- config->cb.buffer_finalize(buf,
- channel_get_private(chan),
- cpu, handle);
- if (buf->backend.allocated)
- lib_ring_buffer_switch_slow(buf, SWITCH_FLUSH,
- handle);
- /*
- * Perform flush before writing to finalized.
- */
- cmm_smp_wmb();
- CMM_ACCESS_ONCE(buf->finalized) = 1;
- //wake_up_interruptible(&buf->read_wait);
- }
- } else {
- struct lttng_ust_lib_ring_buffer *buf = shmp(handle, chan->backend.buf[0].shmp);
+ /*
+ * Note: the consumer takes care of finalizing and switching the
+ * buffers.
+ */
- if (config->cb.buffer_finalize)
- config->cb.buffer_finalize(buf, channel_get_private(chan), -1, handle);
- if (buf->backend.allocated)
- lib_ring_buffer_switch_slow(buf, SWITCH_FLUSH,
- handle);
- /*
- * Perform flush before writing to finalized.
- */
- cmm_smp_wmb();
- CMM_ACCESS_ONCE(buf->finalized) = 1;
- //wake_up_interruptible(&buf->read_wait);
- }
- CMM_ACCESS_ONCE(chan->finalized) = 1;
- //wake_up_interruptible(&chan->hp_wait);
- //wake_up_interruptible(&chan->read_wait);
/*
* sessiond/consumer are keeping a reference on the shm file
* descriptor directly. No need to refcount.
const struct lttng_ust_lib_ring_buffer_config *config,
struct channel *chan, int cpu,
struct lttng_ust_shm_handle *handle,
- int *shm_fd, int *wait_fd,
- uint64_t *memory_map_size)
+ int **shm_fd, int **wait_fd,
+ uint64_t **memory_map_size)
{
struct shm_ref *ref;
const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
unsigned long write_offset, cons_offset;
- /*
- * Can be called in the error path of allocation when
- * trans_channel_data is not yet set.
- */
- if (!chan)
- return;
/*
* No need to order commit_count, write_offset and cons_offset reads
* because we execute at teardown when no more writer nor reader
void lib_ring_buffer_switch_old_start(struct lttng_ust_lib_ring_buffer *buf,
struct channel *chan,
struct switch_offsets *offsets,
- u64 tsc,
+ uint64_t tsc,
struct lttng_ust_shm_handle *handle)
{
const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
void lib_ring_buffer_switch_old_end(struct lttng_ust_lib_ring_buffer *buf,
struct channel *chan,
struct switch_offsets *offsets,
- u64 tsc,
+ uint64_t tsc,
struct lttng_ust_shm_handle *handle)
{
const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
void lib_ring_buffer_switch_new_start(struct lttng_ust_lib_ring_buffer *buf,
struct channel *chan,
struct switch_offsets *offsets,
- u64 tsc,
+ uint64_t tsc,
struct lttng_ust_shm_handle *handle)
{
const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
void lib_ring_buffer_switch_new_end(struct lttng_ust_lib_ring_buffer *buf,
struct channel *chan,
struct switch_offsets *offsets,
- u64 tsc,
+ uint64_t tsc,
struct lttng_ust_shm_handle *handle)
{
const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
struct lttng_ust_lib_ring_buffer *buf,
struct channel *chan,
struct switch_offsets *offsets,
- u64 *tsc)
+ uint64_t *tsc)
{
const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
unsigned long off;
const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
struct switch_offsets offsets;
unsigned long oldidx;
- u64 tsc;
+ uint64_t tsc;
offsets.size = 0;
- subbuf_trunc((unsigned long)
uatomic_read(&buf->consumed), chan)
>= chan->backend.buf_size)) {
+ unsigned long nr_lost;
+
/*
* We do not overwrite non consumed buffers
* and we are full : record is lost.
*/
+ nr_lost = v_read(config, &buf->records_lost_full);
v_inc(config, &buf->records_lost_full);
+ if ((nr_lost & (DBG_PRINT_NR_LOST - 1)) == 0) {
+ DBG("%lu or more records lost in (%s:%d) (buffer full)\n",
+ nr_lost + 1, chan->backend.name,
+ buf->backend.cpu);
+ }
return -ENOBUFS;
} else {
/*
*/
}
} else {
+ unsigned long nr_lost;
+
/*
* Next subbuffer reserve offset does not match the
* commit offset. Drop record in producer-consumer and
* overwrite mode. Caused by either a writer OOPS or too
* many nested writes over a reserve/commit pair.
*/
+ nr_lost = v_read(config, &buf->records_lost_wrap);
v_inc(config, &buf->records_lost_wrap);
+ if ((nr_lost & (DBG_PRINT_NR_LOST - 1)) == 0) {
+ DBG("%lu or more records lost in (%s:%d) (wrap-around)\n",
+ nr_lost + 1, chan->backend.name,
+ buf->backend.cpu);
+ }
return -EIO;
}
offsets->size =
+ ctx->data_size;
if (caa_unlikely(subbuf_offset(offsets->begin, chan)
+ offsets->size > chan->backend.subbuf_size)) {
+ unsigned long nr_lost;
+
/*
* Record too big for subbuffers, report error, don't
* complete the sub-buffer switch.
*/
+ nr_lost = v_read(config, &buf->records_lost_big);
v_inc(config, &buf->records_lost_big);
+ if ((nr_lost & (DBG_PRINT_NR_LOST - 1)) == 0) {
+ DBG("%lu or more records lost in (%s:%d) record size "
+ " of %zu bytes is too large for buffer\n",
+ nr_lost + 1, chan->backend.name,
+ buf->backend.cpu, offsets->size);
+ }
return -ENOSPC;
} else {
/*
ctx->buf_offset = offsets.begin + offsets.pre_header_padding;
return 0;
}
+
+/*
+ * Force a read (imply TLS fixup for dlopen) of TLS variables.
+ */
+void lttng_fixup_ringbuffer_tls(void)
+{
+ asm volatile ("" : : "m" (lib_ring_buffer_nesting));
+}
projects / lttng-ust.git / blobdiff