From: Neil Horman <nhorman@tuxdriver.com>
To: Yerden Zhumabekov <e_zhumabekov@sts.kz>
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH v4 3/5] hash: add fallback to software CRC32 implementation
Date: Tue, 18 Nov 2014 11:00:05 -0500 [thread overview]
Message-ID: <20141118160005.GC32375@hmsreliant.think-freely.org> (raw)
In-Reply-To: <546B607B.9030808@sts.kz>
On Tue, Nov 18, 2014 at 09:06:35PM +0600, Yerden Zhumabekov wrote:
>
> 18.11.2014 20:41, Neil Horman пишет:
> > On Tue, Nov 18, 2014 at 08:03:40PM +0600, Yerden Zhumabekov wrote:
> >> Initially, SSE4.2 support is detected via CPUID instruction.
> >>
> >> Added rte_hash_crc_set_alg() function to detect and set CRC32
> >> implementation if necessary. SSE4.2 is allowed by default. If it's
> >> not available, fall back to sw implementation.
> >>
> >> Best available algorithm is detected upon application startup
> >> through the constructor function rte_hash_crc_try_sse442().
> >>
> >> Signed-off-by: Yerden Zhumabekov <e_zhumabekov@sts.kz>
> >> ---
> >> lib/librte_hash/rte_hash_crc.h | 53 ++++++++++++++++++++++++++++++++++++++--
> >> 1 file changed, 51 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/lib/librte_hash/rte_hash_crc.h b/lib/librte_hash/rte_hash_crc.h
> >> index 15f687a..332ed99 100644
> >> --- a/lib/librte_hash/rte_hash_crc.h
> >> +++ b/lib/librte_hash/rte_hash_crc.h
> >> @@ -45,7 +45,11 @@ extern "C" {
> >> #endif
> >>
> >> #include <stdint.h>
> >> +#ifdef RTE_MACHINE_CPUFLAG_SSE4_2
> >> #include <nmmintrin.h>
> >> +#endif
> >> +#include <rte_cpuflags.h>
> >> +#include <rte_branch_prediction.h>
> >>
> >> /* Lookup tables for software implementation of CRC32C */
> >> static uint32_t crc32c_tables[8][256] = {{
> >> @@ -363,8 +367,41 @@ crc32c_2words(uint64_t data, uint32_t init_val)
> >> return crc;
> >> }
> >>
> >> +enum crc32_alg_t {
> >> + CRC32_SW = 0,
> >> + CRC32_SSE42
> >> +};
> >> +
> >> +static enum crc32_alg_t crc32_alg;
> >> +
> >> +/**
> >> + * Allow or disallow use of SSE4.2 instrinsics for CRC32 hash
> >> + * calculation.
> >> + *
> >> + * @param flag
> >> + * unsigned integer flag
> >> + * - (CRC32_SW) Don't use SSE4.2 intrinsics
> >> + * - (CRC32_SSE42) Use SSE4.2 intrinsics if available, set by default
> >> + */
> >> +static inline void
> >> +rte_hash_crc_set_alg(enum crc32_alg_t alg)
> >> +{
> >> + int sse42_supp = rte_cpu_get_flag_enabled(RTE_CPUFLAG_SSE4_2);
> >> + enum crc32_alg_t alg_supp = sse42_supp ? CRC32_SSE42 : CRC32_SW;
> >> + crc32_alg = (alg == CRC32_SSE42) ? alg_supp : CRC32_SW;
> >> +}
> >> +
> >> +/* Best available algorithm is detected via CPUID instruction */
> >> +static inline void __attribute__((constructor))
> >> +rte_hash_crc_try_sse42(void)
> >> +{
> >> + rte_hash_crc_set_alg(CRC32_SSE42);
> >> +}
> >> +
> >> /**
> >> * Use single crc32 instruction to perform a hash on a 4 byte value.
> >> + * Fall back to software crc32 implementation in case SSE4.2 is
> >> + * not supported
> >> *
> >> * @param data
> >> * Data to perform hash on.
> >> @@ -376,11 +413,18 @@ crc32c_2words(uint64_t data, uint32_t init_val)
> >> static inline uint32_t
> >> rte_hash_crc_4byte(uint32_t data, uint32_t init_val)
> >> {
> >> - return _mm_crc32_u32(init_val, data);
> >> +#ifdef RTE_MACHINE_CPUFLAG_SSE4_2
> >> + if (likely(crc32_alg == CRC32_SSE42))
> >> + return _mm_crc32_u32(init_val, data);
> >> +#endif
> > you don't really need these ifdefs here anymore given that you have a
> > constructor to do the algorithm selection. In fact you need to remove them, in
> > the event you build on a system that doesn't support SSE42, but run on a system
> > that does.
>
> Originally, I thought so as well. I wrote the code without these ifdefs,
> but it didn't compile on my machine which doesn't support SSE4.2. Error
> was triggered by nmmintrin.h which has a check for respective GCC
> extension. So I think these ifdefs are indeed required.
>
You need to edit the makefile so that the compiler gets passed the option
-msse42. That way it will know to emit sse42 instructions. It will also allow
you to remove the ifdef from the include file
Neil
> --
> Sincerely,
>
> Yerden Zhumabekov
> State Technical Service
> Astana, KZ
>
>
>
next prev parent reply other threads:[~2014-11-18 15:49 UTC|newest]
Thread overview: 98+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-03 6:05 [dpdk-dev] [PATCH 0/2] rewritten rte_hash_crc() call Yerden Zhumabekov
2014-09-03 6:05 ` [dpdk-dev] [PATCH 1/2] hash: add new rte_hash_crc_8byte call Yerden Zhumabekov
2014-09-03 6:05 ` [dpdk-dev] [PATCH 2/2] hash: rte_hash_crc uses 8- and 4-byte CRC32 intrinsics Yerden Zhumabekov
2014-11-13 17:33 ` [dpdk-dev] [PATCH 0/2] rewritten rte_hash_crc() call Thomas Monjalon
2014-11-14 0:52 ` Neil Horman
2014-11-14 7:15 ` Yerden Zhumabekov
2014-11-14 11:33 ` Neil Horman
2014-11-14 11:57 ` Yerden Zhumabekov
2014-11-14 13:53 ` Neil Horman
2014-11-14 14:33 ` Thomas Monjalon
2014-11-14 16:43 ` Yerden Zhumabekov
2014-11-14 18:41 ` Neil Horman
2014-11-15 21:45 ` Yerden Zhumabekov
2014-11-16 17:59 ` [dpdk-dev] [PATCH v2 0/4] rte_hash_crc reworked to be platform-independent Yerden Zhumabekov
2014-11-17 11:31 ` Neil Horman
2014-11-17 11:54 ` Yerden Zhumabekov
2014-11-25 17:05 ` Stephen Hemminger
2014-11-18 3:21 ` [dpdk-dev] [PATCH v3 0/5] " Yerden Zhumabekov
2014-11-18 3:21 ` [dpdk-dev] [PATCH v3 1/5] hash: add software CRC32 implementation Yerden Zhumabekov
2014-11-25 17:34 ` Stephen Hemminger
2014-11-18 3:21 ` [dpdk-dev] [PATCH v3 2/5] hash: add new rte_hash_crc_8byte call Yerden Zhumabekov
2014-11-18 3:21 ` [dpdk-dev] [PATCH v3 3/5] hash: add fallback to software CRC32 implementation Yerden Zhumabekov
2014-11-18 4:56 ` Yerden Zhumabekov
2014-11-18 13:33 ` Neil Horman
2014-11-18 13:37 ` Yerden Zhumabekov
2014-11-18 13:43 ` Thomas Monjalon
2014-11-18 3:21 ` [dpdk-dev] [PATCH v3 4/5] hash: rte_hash_crc() slices data into 8-byte pieces Yerden Zhumabekov
2014-11-18 3:25 ` [dpdk-dev] [PATCH v3 5/5] test: remove redundant compile checks Yerden Zhumabekov
2014-11-16 17:59 ` [dpdk-dev] [PATCH v2 1/4] hash: add software CRC32 implementation Yerden Zhumabekov
2014-11-16 17:59 ` [dpdk-dev] [PATCH v2 2/4] hash: add new rte_hash_crc_8byte call Yerden Zhumabekov
2014-11-16 17:59 ` [dpdk-dev] [PATCH v2 3/4] hash: add fallback to software CRC32 implementation Yerden Zhumabekov
2014-11-17 12:34 ` Ananyev, Konstantin
2014-11-17 12:41 ` Yerden Zhumabekov
2014-11-17 14:06 ` Neil Horman
2014-11-16 17:59 ` [dpdk-dev] [PATCH v2 4/4] hash: rte_hash_crc() slices data into 8-byte pieces Yerden Zhumabekov
2014-11-18 14:03 ` [dpdk-dev] [PATCH v4 0/5] rte_hash_crc reworked to be platform-independent Yerden Zhumabekov
2014-11-18 14:03 ` [dpdk-dev] [PATCH v4 1/5] hash: add software CRC32 implementation Yerden Zhumabekov
2014-11-18 14:03 ` [dpdk-dev] [PATCH v4 2/5] hash: add new rte_hash_crc_8byte call Yerden Zhumabekov
2014-11-18 14:03 ` [dpdk-dev] [PATCH v4 3/5] hash: add fallback to software CRC32 implementation Yerden Zhumabekov
2014-11-18 14:41 ` Neil Horman
2014-11-18 15:06 ` Yerden Zhumabekov
2014-11-18 16:00 ` Neil Horman [this message]
2014-11-18 16:04 ` Bruce Richardson
2014-11-18 16:08 ` Bruce Richardson
2014-11-18 16:38 ` Neil Horman
2014-11-18 17:13 ` Yerden Zhumabekov
2014-11-18 17:29 ` Wang, Shawn
2014-11-19 4:07 ` Yerden Zhumabekov
2014-11-18 17:46 ` Neil Horman
2014-11-18 17:52 ` Bruce Richardson
2014-11-18 21:36 ` Neil Horman
2014-11-19 3:51 ` Yerden Zhumabekov
2014-11-19 10:16 ` Bruce Richardson
2014-11-19 11:34 ` Neil Horman
2014-11-19 11:38 ` Bruce Richardson
2014-11-19 11:50 ` Ananyev, Konstantin
2014-11-19 11:59 ` Yerden Zhumabekov
2014-11-19 15:05 ` Neil Horman
2014-11-19 16:51 ` Ananyev, Konstantin
2014-11-19 11:35 ` Yerden Zhumabekov
2014-11-19 15:07 ` Neil Horman
2014-11-20 3:04 ` Yerden Zhumabekov
2014-11-18 17:58 ` Yerden Zhumabekov
2014-11-18 14:03 ` [dpdk-dev] [PATCH v4 4/5] hash: rte_hash_crc() slices data into 8-byte pieces Yerden Zhumabekov
2014-11-18 14:05 ` [dpdk-dev] [PATCH v4 5/5] test: remove redundant compile checks Yerden Zhumabekov
2014-11-20 5:15 ` [dpdk-dev] [PATCH v5 0/7] rte_hash_crc reworked to be platform-independent Yerden Zhumabekov
2014-11-20 5:16 ` [dpdk-dev] [PATCH v5 1/7] hash: add software CRC32 implementation Yerden Zhumabekov
2014-11-20 5:16 ` [dpdk-dev] [PATCH v5 2/7] hash: add assembly implementation of CRC32 intrinsics Yerden Zhumabekov
2014-11-20 5:16 ` [dpdk-dev] [PATCH v5 3/7] hash: replace built-in functions implementing SSE4.2 Yerden Zhumabekov
2014-11-20 5:16 ` [dpdk-dev] [PATCH v5 4/7] hash: add rte_hash_crc_8byte function Yerden Zhumabekov
2014-11-21 11:22 ` Neil Horman
2014-11-21 11:26 ` Yerden Zhumabekov
2014-11-20 5:17 ` [dpdk-dev] [PATCH v5 6/7] hash: rte_hash_crc() slices data into 8-byte pieces Yerden Zhumabekov
2014-11-20 5:17 ` [dpdk-dev] [PATCH v5 7/7] test: remove redundant compile checks Yerden Zhumabekov
2014-11-20 5:17 ` [dpdk-dev] [PATCH v5 5/7] hash: add fallback to software CRC32 implementation Yerden Zhumabekov
2014-11-27 21:04 ` [dpdk-dev] [PATCH v5 0/7] rte_hash_crc reworked to be platform-independent Thomas Monjalon
2014-11-28 3:28 ` Yerden Zhumabekov
2015-01-29 8:48 ` [dpdk-dev] [PATCH v6 " Yerden Zhumabekov
2015-01-29 8:48 ` [dpdk-dev] [PATCH v6 1/7] hash: add software CRC32 implementation Yerden Zhumabekov
2015-01-29 8:48 ` [dpdk-dev] [PATCH v6 2/7] hash: add assembly implementation of CRC32 intrinsics Yerden Zhumabekov
2015-02-02 5:15 ` Liang, Cunming
2015-02-02 5:34 ` Yerden Zhumabekov
2015-02-02 5:59 ` Liang, Cunming
2015-01-29 8:49 ` [dpdk-dev] [PATCH v6 3/7] hash: replace built-in functions implementing SSE4.2 Yerden Zhumabekov
2015-01-29 8:49 ` [dpdk-dev] [PATCH v6 4/7] hash: add rte_hash_crc_8byte function Yerden Zhumabekov
2015-01-29 8:50 ` [dpdk-dev] [PATCH v6 5/7] hash: add fallback to software CRC32 implementation Yerden Zhumabekov
2015-01-29 8:50 ` [dpdk-dev] [PATCH v6 6/7] hash: rte_hash_crc() slices data into 8-byte pieces Yerden Zhumabekov
2015-01-29 8:50 ` [dpdk-dev] [PATCH v6 7/7] test: remove redundant compile checks Yerden Zhumabekov
2015-02-01 14:13 ` [dpdk-dev] [PATCH v6 0/7] rte_hash_crc reworked to be platform-independent Neil Horman
2015-02-02 3:07 ` Yerden Zhumabekov
2015-02-02 3:31 ` Neil Horman
2015-02-02 5:18 ` [dpdk-dev] HA: " Жумабеков Ерден Мирзагулович
2015-02-02 5:39 ` [dpdk-dev] " Yerden Zhumabekov
2015-02-19 15:21 ` Bruce Richardson
2015-02-23 17:36 ` Thomas Monjalon
2015-02-24 3:00 ` Yerden Zhumabekov
2015-02-24 3:10 ` Thomas Monjalon
2015-02-24 9:12 ` Bruce Richardson
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