#include <assert.h>
#include <ust/core.h>
+#include <ust/clock.h>
-#include "usterr.h"
+#include "usterr_signal_safe.h"
#include "channels.h"
#include "tracerconst.h"
#include "tracercore.h"
-#include "header-inline.h"
-
-/***** FIXME: SHOULD BE REMOVED ***** */
/*
* BUFFER_TRUNC zeroes the subbuffer offset and the subbuffer number parts of
/**************************************/
+/*
+ * TODO: using "long" type for struct ust_buffer (control structure
+ * shared between traced apps and the consumer) is a very bad idea when
+ * we get to systems with mixed 32/64-bit processes.
+ *
+ * But on 64-bit system, we want the full power of 64-bit counters,
+ * which wraps less often. Therefore, it's not as easy as "use 32-bit
+ * types everywhere".
+ *
+ * One way to deal with this is to:
+ * 1) Design 64-bit consumer so it can detect 32-bit and 64-bit apps.
+ * 2) The 32-bit consumer only supports 32-bit apps.
+ */
+
struct commit_counters {
long cc; /* ATOMIC */
long cc_sb; /* ATOMIC - Incremented _once_ at sb switch */
int data_ready_fd_write;
/* the reading end of the pipe */
int data_ready_fd_read;
+ /*
+ * List of buffers with an open pipe, used for fork and forced subbuffer
+ * switch.
+ */
+ struct cds_list_head open_buffers_list;
unsigned int finalized;
//ust// struct timer_list switch_timer; /* timer for periodical switch */
struct ust_channel *chan;
- struct kref kref;
+ struct urcu_ref urcu_ref;
void *buf_data;
size_t buf_size;
int shmid;
unsigned int cpu;
/* commit count per subbuffer; must be at end of struct */
- long commit_seq[0] ____cacheline_aligned; /* ATOMIC */
+ long commit_seq[0]; /* ATOMIC */
} ____cacheline_aligned;
/*
- * A switch is done during tracing or as a final flush after tracing (so it
- * won't write in the new sub-buffer).
- * FIXME: make this message clearer
+ * A switch is either done during tracing (FORCE_ACTIVE) or as a final
+ * flush after tracing (with FORCE_FLUSH). FORCE_FLUSH ensures we won't
+ * write in the new sub-buffer).
*/
enum force_switch_mode { FORCE_ACTIVE, FORCE_FLUSH };
extern void ltt_force_switch_lockless_slow(struct ust_buffer *buf,
enum force_switch_mode mode);
+#ifndef HAVE_EFFICIENT_UNALIGNED_ACCESS
+
+/*
+ * Calculate the offset needed to align the type.
+ * size_of_type must be non-zero.
+ */
+static inline unsigned int ltt_align(size_t align_drift, size_t size_of_type)
+{
+ size_t alignment = min(sizeof(void *), size_of_type);
+ return (alignment - align_drift) & (alignment - 1);
+}
+/* Default arch alignment */
+#define LTT_ALIGN
+
+static inline int ltt_get_alignment(void)
+{
+ return sizeof(void *);
+}
+
+#else /* HAVE_EFFICIENT_UNALIGNED_ACCESS */
+
+static inline unsigned int ltt_align(size_t align_drift,
+ size_t size_of_type)
+{
+ return 0;
+}
+
+#define LTT_ALIGN __attribute__((packed))
+
+static inline int ltt_get_alignment(void)
+{
+ return 0;
+}
+#endif /* HAVE_EFFICIENT_UNALIGNED_ACCESS */
static __inline__ void ust_buffers_do_copy(void *dest, const void *src, size_t len)
{
}
#endif
+/*
+ * ust_get_header_size
+ *
+ * Calculate alignment offset to 32-bits. This is the alignment offset of the
+ * event header.
+ *
+ * Important note :
+ * The event header must be 32-bits. The total offset calculated here :
+ *
+ * Alignment of header struct on 32 bits (min arch size, header size)
+ * + sizeof(header struct) (32-bits)
+ * + (opt) u16 (ext. event id)
+ * + (opt) u16 (event_size) (if event_size == 0xFFFFUL, has ext. event size)
+ * + (opt) u32 (ext. event size)
+ * + (opt) u64 full TSC (aligned on min(64-bits, arch size))
+ *
+ * The payload must itself determine its own alignment from the biggest type it
+ * contains.
+ * */
+static __inline__ unsigned char ust_get_header_size(
+ struct ust_channel *channel,
+ size_t offset,
+ size_t data_size,
+ size_t *before_hdr_pad,
+ unsigned int rflags)
+{
+ size_t orig_offset = offset;
+ size_t padding;
+
+ padding = ltt_align(offset, sizeof(struct ltt_event_header));
+ offset += padding;
+ offset += sizeof(struct ltt_event_header);
+
+ if(unlikely(rflags)) {
+ switch (rflags) {
+ case LTT_RFLAG_ID_SIZE_TSC:
+ offset += sizeof(u16) + sizeof(u16);
+ if (data_size >= 0xFFFFU)
+ offset += sizeof(u32);
+ offset += ltt_align(offset, sizeof(u64));
+ offset += sizeof(u64);
+ break;
+ case LTT_RFLAG_ID_SIZE:
+ offset += sizeof(u16) + sizeof(u16);
+ if (data_size >= 0xFFFFU)
+ offset += sizeof(u32);
+ break;
+ case LTT_RFLAG_ID:
+ offset += sizeof(u16);
+ break;
+ }
+ }
+
+ *before_hdr_pad = padding;
+ return offset - orig_offset;
+}
+
static __inline__ void ltt_reserve_push_reader(
struct ust_channel *rchan,
struct ust_buffer *buf,
consumed_idx = SUBBUF_INDEX(consumed_old, buf->chan);
commit_count = uatomic_read(&buf->commit_count[consumed_idx].cc_sb);
/*
- * No memory barrier here, since we are only interested
+ * No memory cmm_barrier here, since we are only interested
* in a statistically correct polling result. The next poll will
* get the data is we are racing. The mb() that ensures correct
* memory order is in get_subbuf.
*tsc = trace_clock_read64();
-//ust// #ifdef CONFIG_LTT_VMCORE
-//ust// prefetch(&buf->commit_count[SUBBUF_INDEX(*o_begin, rchan)]);
-//ust// prefetch(&buf->commit_seq[SUBBUF_INDEX(*o_begin, rchan)]);
-//ust// #else
-//ust// prefetchw(&buf->commit_count[SUBBUF_INDEX(*o_begin, rchan)]);
-//ust// #endif
if (last_tsc_overflow(buf, *tsc))
*rflags = LTT_RFLAG_ID_SIZE_TSC;
/*
* Perform retryable operations.
*/
- /* FIXME: make this really per cpu? */
- if (unlikely(LOAD_SHARED(ltt_nesting) > 4)) {
+ if (unlikely(CMM_LOAD_SHARED(ltt_nesting) > 4)) {
DBG("Dropping event because nesting is too deep.");
uatomic_inc(&buf->events_lost);
return -EPERM;
*/
ltt_reserve_push_reader(chan, buf, o_end - 1);
- /*
- * Clear noref flag for this subbuffer.
- */
-//ust// ltt_clear_noref_flag(chan, buf, SUBBUF_INDEX(o_end - 1, chan));
-
*buf_offset = o_begin + before_hdr_pad;
return 0;
slow_path:
* commit count reaches back the reserve offset (module subbuffer size). It is
* useful for crash dump.
*/
-//ust// #ifdef CONFIG_LTT_VMCORE
static __inline__ void ltt_write_commit_counter(struct ust_channel *chan,
struct ust_buffer *buf, long idx, long buf_offset,
long commit_count, size_t data_size)
DBG("commit_seq for channel %s_%d, subbuf %ld is now %ld", buf->chan->channel_name, buf->cpu, idx, commit_count);
}
-//ust// #else
-//ust// static __inline__ void ltt_write_commit_counter(struct ust_buffer *buf,
-//ust// long idx, long buf_offset, long commit_count, size_t data_size)
-//ust// {
-//ust// }
-//ust// #endif
/*
* Atomic unordered slot commit. Increments the commit count in the
long endidx = SUBBUF_INDEX(offset_end - 1, chan);
long commit_count;
- smp_wmb();
+ cmm_smp_wmb();
uatomic_add(&buf->commit_count[endidx].cc, slot_size);
/*
size_t buf_offset = BUFFER_OFFSET(offset, buf->chan);
assert(buf_offset < buf->chan->subbuf_size*buf->chan->subbuf_cnt);
- assert(buf_offset + len < buf->chan->subbuf_size*buf->chan->subbuf_cnt);
+ assert(buf_offset + len
+ <= buf->chan->subbuf_size*buf->chan->subbuf_cnt);
ust_buffers_do_copy(buf->buf_data + buf_offset, src, len);
* don't have constants, so gcc generally uses a function call.
*/
for (; len > 0; len--) {
- *(u8 *)dest = LOAD_SHARED(*(const u8 *)src);
+ *(u8 *)dest = CMM_LOAD_SHARED(*(const u8 *)src);
/* Check with dest, because src may be modified concurrently */
if (*(const u8 *)dest == '\0') {
len--;
int terminated;
assert(buf_offset < buf->chan->subbuf_size*buf->chan->subbuf_cnt);
- assert(buf_offset + len < buf->chan->subbuf_size*buf->chan->subbuf_cnt);
+ assert(buf_offset + len
+ <= buf->chan->subbuf_size*buf->chan->subbuf_cnt);
copied = ust_buffers_do_strncpy(buf->buf_data + buf_offset,
src, len, &terminated);
projects / ust.git / blobdiff