diff options
| author |   Dave Barach <dave@barachs.net> | 2019-01-24 10:34:24 -0500 |
|---|---|---|
| committer |   Damjan Marion <dmarion@me.com> | 2019-01-24 16:19:04 +0000 |
| commit | ec595ef02639005b34334097af76b41ceef3dca5 (patch) | |
| tree | b8b752d9c9371b9ea75a9a28bfa1a3a6e7494b18 /src/vlib/main.h | |
| parent | 22f23ae802f6dc654dbef27340c67773eb8be8c3 (diff) | |
perfmon plugin: 2-way parallel stat collection
As a FUD reduction measure, this patch implements 2-way parallel
counter collection. Synthetic stat component counter pairs run at the
same time. Running two counters (of any kind) at the same time
naturally reduces the aggregate time required by an approximate
factor-of-2, depending on whether an even or odd number of stats have
been requested.
I don't completely buy the argument that computing synthetic stats
such as instructions-per-clock will be inaccurate if component counter
values are collected sequentially. Given uniform traffic pattern, it
must make no difference.
As the collection interval increases, the difference between serial
and parallel component counter collection will approach zero, see also
the Central Limit theorem.
Change-Id: I36ebdcf125e8882cca8a1929ec58f17fba1ad8f1
Signed-off-by: Dave Barach <dave@barachs.net>
Diffstat (limited to 'src/vlib/main.h')
| -rw-r--r-- | src/vlib/main.h | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/src/vlib/main.h b/src/vlib/main.h index 91661fdaaad..4c6d0f490dd 100644 --- a/src/vlib/main.h +++ b/src/vlib/main.h @@ -84,9 +84,8 @@ typedef struct vlib_main_t u32 node_counts_per_main_loop[2]; /* Main loop hw / sw performance counters */ - u64 (*vlib_node_runtime_perf_counter_cb) (struct vlib_main_t *); - int perf_counter_id; - int perf_counter_fd; + void (*vlib_node_runtime_perf_counter_cb) (struct vlib_main_t *, + u64 *, u64 *); /* Every so often we switch to the next counter. */ #define VLIB_LOG2_MAIN_LOOPS_PER_STATS_UPDATE 7 |