From: Bruce Richardson <bruce.richardson@intel.com>
To: dev@dpdk.org
Cc: yingyax.han@intel.com, konstantin.ananyev@intel.com,
lijuan.tu@intel.com,
Bruce Richardson <bruce.richardson@intel.com>
Subject: [dpdk-dev] [PATCH] build: fix memcpy behaviour regression
Date: Mon, 12 Oct 2020 15:51:48 +0100 [thread overview]
Message-ID: <20201012145148.290451-1-bruce.richardson@intel.com> (raw)
When testing on some x86 platforms, code compiled with meson was observed
running at a different power-license level to that compiled with make. This
is due to the fact that meson auto-detects the instruction sets available
on the system and enabled AVX512 rte_memcpy when AVX512 was available,
while on make, a build time AVX-512 flag needed to be explicitly set to
enable that AVX512 rte_memcpy code path.
In the absense of runtime path selection for rte_memcpy - which is
complicated by it being a static inline function in a header file - we can
fix this behaviour regression by similarly having a build-time option which
must be set to enable the AVX-512 memcpy path.
Fixes: a25a650be5f0 ("build: add infrastructure for meson and ninja builds")
Fixes: 3e1bb55fd6ef ("build/x86: add SSE flags")
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---
NOTE: This patch is not suitable for backporting, as it will break the
build support for make builds without addition makefile changes.
---
lib/librte_eal/include/generic/rte_memcpy.h | 4 ++++
lib/librte_eal/x86/include/rte_memcpy.h | 2 +-
2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/lib/librte_eal/include/generic/rte_memcpy.h b/lib/librte_eal/include/generic/rte_memcpy.h
index 701e550c3..e7f0f8eaa 100644
--- a/lib/librte_eal/include/generic/rte_memcpy.h
+++ b/lib/librte_eal/include/generic/rte_memcpy.h
@@ -95,6 +95,10 @@ rte_mov256(uint8_t *dst, const uint8_t *src);
* @note This is implemented as a macro, so it's address should not be taken
* and care is needed as parameter expressions may be evaluated multiple times.
*
+ * @note For x86 platforms to enable the AVX-512 memcpy implementation, set
+ * -DRTE_MEMCPY_AVX512 macro in CFLAGS, or define the RTE_MEMCPY_AVX512 macro
+ * explicitly in the source file before including the rte_memcpy header file.
+ *
* @param dst
* Pointer to the destination of the data.
* @param src
diff --git a/lib/librte_eal/x86/include/rte_memcpy.h b/lib/librte_eal/x86/include/rte_memcpy.h
index 008a3de67..79f381dd9 100644
--- a/lib/librte_eal/x86/include/rte_memcpy.h
+++ b/lib/librte_eal/x86/include/rte_memcpy.h
@@ -45,7 +45,7 @@ extern "C" {
static __rte_always_inline void *
rte_memcpy(void *dst, const void *src, size_t n);
-#ifdef __AVX512F__
+#if defined __AVX512F__ && defined RTE_MEMCPY_AVX512
#define ALIGNMENT_MASK 0x3F
--
2.25.1
next reply other threads:[~2020-10-12 14:52 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-12 14:51 Bruce Richardson [this message]
2020-10-16 2:13 ` Han, YingyaX
2020-10-17 10:32 ` Thomas Monjalon
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20201012145148.290451-1-bruce.richardson@intel.com \
--to=bruce.richardson@intel.com \
--cc=dev@dpdk.org \
--cc=konstantin.ananyev@intel.com \
--cc=lijuan.tu@intel.com \
--cc=yingyax.han@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).