From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>
If mmapping the ring buffer is available, use that for iterating raw events
as it's less copying than using splice buffering.
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
src/tracefs-events.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/src/tracefs-events.c b/src/tracefs-events.c
index 2571c4b43341..9f620abebdda 100644
--- a/src/tracefs-events.c
+++ b/src/tracefs-events.c
@@ -32,6 +32,7 @@ struct cpu_iterate {
struct tep_event *event;
struct kbuffer *kbuf;
int cpu;
+ bool mapped;
};
static int read_kbuf_record(struct cpu_iterate *cpu)
@@ -66,7 +67,11 @@ int read_next_page(struct tep_handle *tep, struct cpu_iterate *cpu)
if (!cpu->tcpu)
return -1;
- kbuf = tracefs_cpu_buffered_read_buf(cpu->tcpu, true);
+ /* Do not do buffered reads if it is mapped */
+ if (cpu->mapped)
+ kbuf = tracefs_cpu_read_buf(cpu->tcpu, true);
+ else
+ kbuf = tracefs_cpu_buffered_read_buf(cpu->tcpu, true);
/*
* tracefs_cpu_buffered_read_buf() only reads in full subbuffer size,
* but this wants partial buffers as well. If the function returns
@@ -274,7 +279,7 @@ static int open_cpu_files(struct tracefs_instance *instance, cpu_set_t *cpus,
if (snapshot)
tcpu = tracefs_cpu_snapshot_open(instance, cpu, true);
else
- tcpu = tracefs_cpu_open(instance, cpu, true);
+ tcpu = tracefs_cpu_open_mapped(instance, cpu, true);
tmp = realloc(*all_cpus, (i + 1) * sizeof(*tmp));
if (!tmp) {
i--;
@@ -290,6 +295,7 @@ static int open_cpu_files(struct tracefs_instance *instance, cpu_set_t *cpus,
tmp[i].tcpu = tcpu;
tmp[i].cpu = cpu;
+ tmp[i].mapped = tracefs_cpu_is_mapped(tcpu);
i++;
}
*count = i;
--
2.43.0
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