We're attempting to slacken the mirror loop in three different places,
but we can combine these three attempts. Combine the early loop call to
block_job_pause_point with the two late-loop calls to block_job_sleep_ns.
When delay_ns is 0 and it has not been SLICE_TIME since the last yield,
block_job_relax is merely a call to block_job_pause_point, so this should
be equivalent with the exception that if we have managed to not yield at
all in the last SLICE_TIME ns, we will now do so.
I am not sure that condition was possible,
so this loop should be equivalent.
Signed-off-by: John Snow <js...@redhat.com>
---
block/mirror.c | 22 +++++++++++-----------
block/trace-events | 2 +-
2 files changed, 12 insertions(+), 12 deletions(-)
diff --git a/block/mirror.c b/block/mirror.c
index a0e0044de2..192e03694f 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -761,7 +761,7 @@ static void coroutine_fn mirror_run(void *opaque)
assert(!s->dbi);
s->dbi = bdrv_dirty_iter_new(s->dirty_bitmap);
for (;;) {
- uint64_t delay_ns = 0;
+ static uint64_t delay_ns = 0;
int64_t cnt, delta;
bool should_complete;
@@ -770,9 +770,16 @@ static void coroutine_fn mirror_run(void *opaque)
goto immediate_exit;
}
- block_job_pause_point(&s->common);
-
cnt = bdrv_get_dirty_count(s->dirty_bitmap);
+
+ trace_mirror_before_relax(s, cnt, s->synced, delay_ns);
+ if (block_job_relax(&s->common, delay_ns)) {
+ if (!s->synced) {
+ goto immediate_exit;
+ }
+ }
+ delay_ns = 0;
+
/* s->common.offset contains the number of bytes already processed so
* far, cnt is the number of dirty bytes remaining and
* s->bytes_in_flight is the number of bytes currently being
@@ -849,15 +856,8 @@ static void coroutine_fn mirror_run(void *opaque)
}
ret = 0;
- trace_mirror_before_sleep(s, cnt, s->synced, delay_ns);
- if (!s->synced) {
- block_job_sleep_ns(&s->common, delay_ns);
- if (block_job_is_cancelled(&s->common)) {
- break;
- }
- } else if (!should_complete) {
+ if (s->synced && !should_complete) {
delay_ns = (s->in_flight == 0 && cnt == 0 ? SLICE_TIME : 0);
- block_job_sleep_ns(&s->common, delay_ns);
}
}
diff --git a/block/trace-events b/block/trace-events
index 11c8d5f590..60f36f929a 100644
--- a/block/trace-events
+++ b/block/trace-events
@@ -27,7 +27,7 @@ mirror_start(void *bs, void *s, void *opaque) "bs %p s %p
opaque %p"
mirror_restart_iter(void *s, int64_t cnt) "s %p dirty count %"PRId64
mirror_before_flush(void *s) "s %p"
mirror_before_drain(void *s, int64_t cnt) "s %p dirty count %"PRId64
-mirror_before_sleep(void *s, int64_t cnt, int synced, uint64_t delay_ns) "s %p
dirty count %"PRId64" synced %d delay %"PRIu64"ns"
+mirror_before_relax(void *s, int64_t cnt, int synced, uint64_t delay_ns) "s %p
dirty count %"PRId64" synced %d delay %"PRIu64"ns"
mirror_one_iteration(void *s, int64_t offset, uint64_t bytes) "s %p offset %"
PRId64 " bytes %" PRIu64
mirror_iteration_done(void *s, int64_t offset, uint64_t bytes, int ret) "s %p
offset %" PRId64 " bytes %" PRIu64 " ret %d"
mirror_yield(void *s, int64_t cnt, int buf_free_count, int in_flight) "s %p
dirty count %"PRId64" free buffers %d in_flight %d"
--
2.14.3
