From: Stephen Hemminger <stephen@networkplumber.org>
To: Vladimir Medvedkin <medvedkinv@gmail.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH] Add toeplitz hash algorithm
Date: Wed, 8 Apr 2015 15:24:30 -0700 [thread overview]
Message-ID: <20150408152430.0bdedfd6@urahara> (raw)
In-Reply-To: <1428519973-10550-1-git-send-email-medvedkinv@gmail.com>
On Wed, 8 Apr 2015 15:06:13 -0400
Vladimir Medvedkin <medvedkinv@gmail.com> wrote:
> Software implementation of the Toeplitz hash function used by RSS.
> Can be used either for packet distribution on single queue NIC
> or for simulating of RSS computation on specific NIC (for example
> after GRE header decapsulating).
>
> Signed-off-by: Vladimir Medvedkin <medvedkinv@gmail.com>
> +enum rte_thash_flag {
> + RTE_THASH_L3 = 0, //calculate hash tacking into account only l3 header
> + RTE_THASH_L4 //calculate hash tacking into account l4 + l4 headers
> +};
> +
> +/**
> + * Prepare special converted key to use with rte_softrss_be()
> + * @param orig
> + * pointer to original RSS key
> + * @param targ
> + * pointer to target RSS key
> + */
> +
> +static inline void
> +rte_convert_rss_key(uint32_t *orig, uint32_t *targ)
orig should be const
> +{
> + int i;
> + for (i = 0; i < 10; i++) {
> + targ[i] = rte_be_to_cpu_32(orig[i]);
> + }
> +}
> +static inline uint32_t
> +rte_softrss(uint32_t sip, uint32_t dip, uint16_t sp, uint16_t dp, enum rte_thash_flag flag, uint32_t *rss_key)
rss_key should be const
> +{
> + uint32_t ret = 0;
> + int i;
> + for (i = 0; i < 32; i++) {
blank line after declaration please
> + if (sip & (1 << (31 - i))) {
> + ret ^= (rte_cpu_to_be_32(*rss_key) << i)|(uint32_t)((uint64_t)(rte_cpu_to_be_32(*(rss_key + 1))) >> (32 - i));
Long expression > 80 characters.
Repeated multiple times (should be inline)
Extra parens ()
Extension to 64 bits is only to avoid compiler warning?
> + }
> + }
> + rss_key++;
> + for (i = 0; i < 32; i++) {
> + if (dip & (1 << (31 - i))) {
> + ret ^= (rte_cpu_to_be_32(*rss_key) << i)|(uint32_t)((uint64_t)(rte_cpu_to_be_32(*(rss_key + 1))) >> (32 - i));
> + }
> + }
> + if (flag == RTE_THASH_L4) {
> + rss_key++;
> + for (i = 0; i < 32; i++) {
> + if (((sp<<16)|dp) & (1 << (31 - i))) {
> + ret ^= (rte_cpu_to_be_32(*rss_key) << i)|(uint32_t)((uint64_t)(rte_cpu_to_be_32(*(rss_key + 1))) >> (32 - i));
> + }
> + }
> + }
> + return ret;
> +}
> +
> +/**
> + * Optimized implementation.
> + * If you want the calculated hash value matches NIC RSS value
> + * you have to use special converted key.
> + * All ip's and ports have to be CPU byte order.
> + * @param sip
> + * Source ip address.
> + * @param dip
> + * Destination ip address.
> + * @param sp
> + * Source TCP|UDP port.
> + * @param dp
> + * Destination TCP|UDP port.
> + * @param flag
> + * RTE_THASH_L3: calculate hash tacking into account only sip and dip
> + * RTE_THASH_L4: calculate hash tacking into account sip, dip, sp and dp
> + * @param *rss_key
> + * Pointer to 40-byte RSS hash key.
> + * @return
> + * Calculated hash value.
> + */
> +
> +static inline uint32_t
> +rte_softrss_be(uint32_t sip, uint32_t dip, uint16_t sp, uint16_t dp, enum rte_thash_flag flag, uint32_t *rss_key)
> +{
Same problems as previous code.
Also lots of copy paste (see Do Not Repeat Yourself principle).
next prev parent reply other threads:[~2015-04-08 22:24 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-08 19:06 Vladimir Medvedkin
2015-04-08 22:24 ` Stephen Hemminger [this message]
2015-04-09 12:50 ` Vladimir Medvedkin
2015-04-09 6:37 ` Gleb Natapov
2015-04-09 12:57 ` Vladimir Medvedkin
2015-05-05 13:20 ` [dpdk-dev] [PATCH v2] Add toeplitz hash algorithm used by RSS Vladimir Medvedkin
2015-05-05 16:03 ` Chilikin, Andrey
2015-05-07 10:28 ` Vladimir Medvedkin
2015-05-07 11:38 ` Chilikin, Andrey
2015-05-08 14:58 ` Vladimir Medvedkin
2015-05-08 14:58 ` Vladimir Medvedkin
2015-06-03 14:07 ` Thomas Monjalon
2015-06-16 9:07 ` Thomas Monjalon
2015-06-16 10:36 ` Bruce Richardson
2015-06-16 12:29 ` Bruce Richardson
2015-06-16 19:26 ` Vladimir Medvedkin
2015-06-19 14:55 ` [dpdk-dev] [PATCH v4] " Vladimir Medvedkin
2015-06-19 15:59 ` Richardson, Bruce
2015-06-19 16:14 ` Vladimir Medvedkin
2015-06-29 12:18 ` Bruce Richardson
2015-06-19 16:33 ` Mcnamara, John
2015-06-19 17:31 ` [dpdk-dev] [PATCH v5] " Vladimir Medvedkin
2015-06-29 12:40 ` Bruce Richardson
2015-06-30 12:14 ` Vladimir Medvedkin
2015-06-30 12:48 ` Bruce Richardson
2015-06-30 23:40 ` [dpdk-dev] [PATCH v6] " Vladimir Medvedkin
2015-07-01 15:29 ` Bruce Richardson
2015-07-01 21:23 ` Thomas Monjalon
2015-07-22 7:55 ` Tony Lu
2015-07-27 11:57 ` Vladimir Medvedkin
2015-07-29 5:01 ` Qiu, Michael
2015-07-29 14:00 ` Vladimir Medvedkin
2015-06-19 17:32 ` [dpdk-dev] [PATCH v3] Add unit test for thash library Vladimir Medvedkin
2015-06-29 12:42 ` Bruce Richardson
2015-06-30 23:41 ` [dpdk-dev] [PATCH v4] " Vladimir Medvedkin
2015-07-01 15:30 ` Bruce Richardson
2015-07-01 21:28 ` Thomas Monjalon
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