On 12/06/2016 07:33 AM, Yang, Zhiyong wrote:
Hi， Maxime:
-----Original Message-----
From: Maxime Coquelin [mailto:maxime.coque...@redhat.com]
Sent: Friday, December 2, 2016 6:01 PM
To: Yang, Zhiyong <zhiyong.y...@intel.com>; dev@dpdk.org
Cc: yuanhan....@linux.intel.com; Richardson, Bruce
<bruce.richard...@intel.com>; Ananyev, Konstantin
<konstantin.anan...@intel.com>
Subject: Re: [dpdk-dev] [PATCH 0/4] eal/common: introduce rte_memset
and related test
Hi Zhiyong,
On 12/05/2016 09:26 AM, Zhiyong Yang wrote:
DPDK code has met performance drop badly in some case when calling
glibc function memset. Reference to discussions about memset in
http://dpdk.org/ml/archives/dev/2016-October/048628.html
It is necessary to introduce more high efficient function to fix it.
One important thing about rte_memset is that we can get clear control
on what instruction flow is used.
This patchset introduces rte_memset to bring more high efficient
implementation, and will bring obvious perf improvement, especially
for small N bytes in the most application scenarios.
Patch 1 implements rte_memset in the file rte_memset.h on IA platform
The file supports three types of instruction sets including sse & avx
(128bits), avx2(256bits) and avx512(512bits). rte_memset makes use of
vectorization and inline function to improve the perf on IA. In
addition, cache line and memory alignment are fully taken into
consideration.
Patch 2 implements functional autotest to validates the function
whether to work in a right way.
Patch 3 implements performance autotest separately in cache and memory.
Patch 4 Using rte_memset instead of copy_virtio_net_hdr can bring
3%~4% performance improvements on IA platform from virtio/vhost
non-mergeable loopback testing.
Zhiyong Yang (4):
eal/common: introduce rte_memset on IA platform
app/test: add functional autotest for rte_memset
app/test: add performance autotest for rte_memset
lib/librte_vhost: improve vhost perf using rte_memset
app/test/Makefile | 3 +
app/test/test_memset.c | 158 +++++++++
app/test/test_memset_perf.c | 348 +++++++++++++++++++
doc/guides/rel_notes/release_17_02.rst | 11 +
.../common/include/arch/x86/rte_memset.h | 376
+++++++++++++++++++++
lib/librte_eal/common/include/generic/rte_memset.h | 51 +++
lib/librte_vhost/virtio_net.c | 18 +-
7 files changed, 958 insertions(+), 7 deletions(-) create mode
100644 app/test/test_memset.c create mode 100644
app/test/test_memset_perf.c create mode 100644
lib/librte_eal/common/include/arch/x86/rte_memset.h
create mode 100644
lib/librte_eal/common/include/generic/rte_memset.h
Thanks for the series, idea looks good to me.
Wouldn't be worth to also use rte_memset in Virtio PMD (not
compiled/tested)? :
I think rte_memset maybe can bring some benefit here, but , I'm not clear
how to
enter the branch and test it. :)
Indeed, you will need Pierre's patch:
[dpdk-dev] [PATCH] virtio: tx with can_push when VERSION_1 is set
Thanks,
Maxime
thanks
Zhiyong
diff --git a/drivers/net/virtio/virtio_rxtx.c
b/drivers/net/virtio/virtio_rxtx.c
index 22d97a4..a5f70c4 100644
--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c
@@ -287,7 +287,7 @@ virtqueue_enqueue_xmit(struct virtnet_tx *txvq,
struct rte_mbuf *cookie,
rte_pktmbuf_prepend(cookie, head_size);
/* if offload disabled, it is not zeroed below, do it now */
if (offload == 0)
- memset(hdr, 0, head_size);
+ rte_memset(hdr, 0, head_size);
} else if (use_indirect) {
/* setup tx ring slot to point to indirect
* descriptor list stored in reserved region.
Cheers,
Maxime
