#include <linux/delay.h>
#include <linux/module.h>
#include <linux/percpu.h>
+#include <asm/cacheflush.h>
#include <wrapper/ringbuffer/config.h>
#include <wrapper/ringbuffer/backend.h>
#include <wrapper/kref.h>
#include <wrapper/percpu-defs.h>
#include <wrapper/timer.h>
+#include <wrapper/vmalloc.h>
/*
* Internal structure representing offsets to use at a sub-buffer switch.
struct channel *chan = buf->backend.chan;
lib_ring_buffer_print_errors(chan, buf, buf->backend.cpu);
- kfree(buf->commit_hot);
- kfree(buf->commit_cold);
+ lttng_kvfree(buf->commit_hot);
+ lttng_kvfree(buf->commit_cold);
lib_ring_buffer_backend_free(&buf->backend);
}
return ret;
buf->commit_hot =
- kzalloc_node(ALIGN(sizeof(*buf->commit_hot)
+ lttng_kvzalloc_node(ALIGN(sizeof(*buf->commit_hot)
* chan->backend.num_subbuf,
1 << INTERNODE_CACHE_SHIFT),
GFP_KERNEL | __GFP_NOWARN,
}
buf->commit_cold =
- kzalloc_node(ALIGN(sizeof(*buf->commit_cold)
+ lttng_kvzalloc_node(ALIGN(sizeof(*buf->commit_cold)
* chan->backend.num_subbuf,
1 << INTERNODE_CACHE_SHIFT),
GFP_KERNEL | __GFP_NOWARN,
/* Error handling */
free_init:
- kfree(buf->commit_cold);
+ lttng_kvfree(buf->commit_cold);
free_commit:
- kfree(buf->commit_hot);
+ lttng_kvfree(buf->commit_hot);
free_chanbuf:
lib_ring_buffer_backend_free(&buf->backend);
return ret;
unsigned long consumed_cur, write_offset;
int finalized;
- /*
- * First, ensure we perform a "final" flush onto the stream. This will
- * ensure we create a packet of padding if we encounter an empty
- * packet. This ensures the time-stamps right before the snapshot is
- * used as end of packet timestamp.
- */
- if (!buf->quiescent)
- _lib_ring_buffer_switch_remote(buf, SWITCH_FLUSH);
-
retry:
finalized = ACCESS_ONCE(buf->finalized);
/*
}
EXPORT_SYMBOL_GPL(lib_ring_buffer_move_consumer);
+#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
+static void lib_ring_buffer_flush_read_subbuf_dcache(
+ const struct lib_ring_buffer_config *config,
+ struct channel *chan,
+ struct lib_ring_buffer *buf)
+{
+ struct lib_ring_buffer_backend_pages *pages;
+ unsigned long sb_bindex, id, i, nr_pages;
+
+ if (config->output != RING_BUFFER_MMAP)
+ return;
+
+ /*
+ * Architectures with caches aliased on virtual addresses may
+ * use different cache lines for the linear mapping vs
+ * user-space memory mapping. Given that the ring buffer is
+ * based on the kernel linear mapping, aligning it with the
+ * user-space mapping is not straightforward, and would require
+ * extra TLB entries. Therefore, simply flush the dcache for the
+ * entire sub-buffer before reading it.
+ */
+ id = buf->backend.buf_rsb.id;
+ sb_bindex = subbuffer_id_get_index(config, id);
+ pages = buf->backend.array[sb_bindex];
+ nr_pages = buf->backend.num_pages_per_subbuf;
+ for (i = 0; i < nr_pages; i++) {
+ struct lib_ring_buffer_backend_page *backend_page;
+
+ backend_page = &pages->p[i];
+ flush_dcache_page(pfn_to_page(backend_page->pfn));
+ }
+}
+#else
+static void lib_ring_buffer_flush_read_subbuf_dcache(
+ const struct lib_ring_buffer_config *config,
+ struct channel *chan,
+ struct lib_ring_buffer *buf)
+{
+}
+#endif
+
/**
* lib_ring_buffer_get_subbuf - get exclusive access to subbuffer for reading
* @buf: ring buffer
buf->get_subbuf_consumed = consumed;
buf->get_subbuf = 1;
+ lib_ring_buffer_flush_read_subbuf_dcache(config, chan, buf);
+
return 0;
nodata:
/*
* lib_ring_buffer_switch_old_start: Populate old subbuffer header.
*
- * Only executed by SWITCH_FLUSH, which can be issued while tracing is active
- * or at buffer finalization (destroy).
+ * Only executed when the buffer is finalized, in SWITCH_FLUSH.
*/
static
void lib_ring_buffer_switch_old_start(struct lib_ring_buffer *buf,
unsigned long sb_index, commit_count;
/*
- * We are performing a SWITCH_FLUSH. There may be concurrent
- * writes into the buffer if e.g. invoked while performing a
- * snapshot on an active trace.
+ * We are performing a SWITCH_FLUSH. At this stage, there are no
+ * concurrent writes into the buffer.
*
- * If the client does not save any header information (sub-buffer
- * header size == 0), don't switch empty subbuffer on finalize,
- * because it is invalid to deliver a completely empty
- * subbuffer.
+ * The client does not save any header information. Don't
+ * switch empty subbuffer on finalize, because it is invalid to
+ * deliver a completely empty subbuffer.
*/
if (!config->cb.subbuffer_header_size())
return -1;
put_online_cpus();
}
+/* Switch sub-buffer if current sub-buffer is non-empty. */
void lib_ring_buffer_switch_remote(struct lib_ring_buffer *buf)
{
_lib_ring_buffer_switch_remote(buf, SWITCH_ACTIVE);
}
EXPORT_SYMBOL_GPL(lib_ring_buffer_switch_remote);
+/* Switch sub-buffer even if current sub-buffer is empty. */
+void lib_ring_buffer_switch_remote_empty(struct lib_ring_buffer *buf)
+{
+ _lib_ring_buffer_switch_remote(buf, SWITCH_FLUSH);
+}
+EXPORT_SYMBOL_GPL(lib_ring_buffer_switch_remote_empty);
+
/*
* Returns :
* 0 if ok
projects / lttng-modules.git / blobdiff