> -----Original Message----- > From: Neil Horman [mailto:nhorman at tuxdriver.com] > Sent: Monday, January 19, 2015 9:02 PM > To: Wang, Zhihong > Cc: dev at dpdk.org > Subject: Re: [dpdk-dev] [PATCH 0/4] DPDK memcpy optimization > > On Mon, Jan 19, 2015 at 09:53:30AM +0800, zhihong.wang at intel.com wrote: > > This patch set optimizes memcpy for DPDK for both SSE and AVX platforms. > > It also extends memcpy test coverage with unaligned cases and more test > points. > > > > Optimization techniques are summarized below: > > > > 1. Utilize full cache bandwidth > > > > 2. Enforce aligned stores > > > > 3. Apply load address alignment based on architecture features > > > > 4. Make load/store address available as early as possible > > > > 5. General optimization techniques like inlining, branch reducing, > > prefetch pattern access > > > > Zhihong Wang (4): > > Disabled VTA for memcpy test in app/test/Makefile > > Removed unnecessary test cases in test_memcpy.c > > Extended test coverage in test_memcpy_perf.c > > Optimized memcpy in arch/x86/rte_memcpy.h for both SSE and AVX > > platforms > > > > app/test/Makefile | 6 + > > app/test/test_memcpy.c | 52 +- > > app/test/test_memcpy_perf.c | 238 +++++--- > > .../common/include/arch/x86/rte_memcpy.h | 664 > +++++++++++++++------ > > 4 files changed, 656 insertions(+), 304 deletions(-) > > > > -- > > 1.9.3 > > > > > Are you able to compile this with gcc 4.9.2? The compilation of > test_memcpy_perf is taking forever for me. It appears hung. > Neil
Neil, Thanks for reporting this! It should compile but will take quite some time if the CPU doesn't support AVX2, the reason is that: 1. The SSE & AVX memcpy implementation is more complicated than AVX2 version thus the compiler takes more time to compile and optimize 2. The new test_memcpy_perf.c contains 126 constants memcpy calls for better test case coverage, that's quite a lot I've just tested this patch on an Ivy Bridge machine with GCC 4.9.2: 1. The whole compile process takes 9'41" with the original test_memcpy_perf.c (63 + 63 = 126 constant memcpy calls) 2. It takes only 2'41" after I reduce the constant memcpy call number to 12 + 12 = 24 I'll reduce memcpy call in the next version of patch. Zhihong (John)
