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From: Dharmik Thakkar <Dharmik.Thakkar@arm.com>
To: Yipeng Wang <yipeng1.wang@intel.com>
Cc: Pablo de Lara <pablo.de.lara.guarch@intel.com>,
	"gentoorion@gmail.com" <gentoorion@gmail.com>,
	"anatoly.burakov@intel.com" <anatoly.burakov@intel.com>,
	"dev@dpdk.org" <dev@dpdk.org>, nd <nd@arm.com>
Subject: Re: [dpdk-dev] [PATCH] doc: fix rte_hash_hash comment for ambiguity
Date: Mon, 29 Apr 2019 20:05:58 +0000	[thread overview]
Message-ID: <4D954DB3-ACAF-468E-B6C8-51C3E6D9D4DC@arm.com> (raw)
Message-ID: <20190429200558.LKpAVf8ShgSLtlH2b_bXbtCKWsziPa6HTsT23u9yWuE@z> (raw)
In-Reply-To: <1556530816-423522-1-git-send-email-yipeng1.wang@intel.com>


> On Apr 29, 2019, at 4:40 AM, Yipeng Wang <yipeng1.wang@intel.com> wrote:
> 
> rte_hash_hash is multi-thread safe but not multi-process safe
> because of the use of function pointers. Previous document
> and comment says the other way around. This commit fixes
> the issue.
> 
> Fixes: fc1f2750a3ec ("doc: programmers guide")
> Fixes: 48a399119619 ("hash: replace with cuckoo hash implementation")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Yipeng Wang <yipeng1.wang@intel.com>
> Suggested-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
> Reported-by: Andrey Nikolaev <gentoorion@gmail.com>
> ---
> doc/guides/prog_guide/multi_proc_support.rst | 2 +-
> lib/librte_hash/rte_hash.h                   | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/doc/guides/prog_guide/multi_proc_support.rst b/doc/guides/prog_guide/multi_proc_support.rst
> index 1384fe3..761fca9 100644
> --- a/doc/guides/prog_guide/multi_proc_support.rst
> +++ b/doc/guides/prog_guide/multi_proc_support.rst
> @@ -176,7 +176,7 @@ Some of these are documented below:
> 
> *   The use of function pointers between multiple processes running based of different compiled binaries is not supported,
>     since the location of a given function in one process may be different to its location in a second.
> -    This prevents the librte_hash library from behaving properly as in a multi-threaded instance,
> +    This prevents the librte_hash library from behaving properly as in a multi-process instance,
>     since it uses a pointer to the hash function internally.
> 
> To work around this issue, it is recommended that multi-process applications perform the hash calculations by directly calling
> diff --git a/lib/librte_hash/rte_hash.h b/lib/librte_hash/rte_hash.h
> index c93d1a1..abba8d7 100644
> --- a/lib/librte_hash/rte_hash.h
> +++ b/lib/librte_hash/rte_hash.h
> @@ -463,7 +463,7 @@ rte_hash_lookup_with_hash(const struct rte_hash *h,
> 
> /**
>  * Calc a hash value by key.
> - * This operation is not multi-thread safe.
> + * This operation is not multi-process safe.
>  *
>  * @param h
>  *   Hash table to look in.
> -- 
> 2.7.4
> 
Acked-by: Dharmik Thakkar <dharmik.thakkar@arm.com>


  parent reply	other threads:[~2019-04-29 20:06 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-29  9:40 Yipeng Wang
2019-04-29  9:40 ` Yipeng Wang
2019-04-29 20:05 ` Dharmik Thakkar [this message]
2019-04-29 20:05   ` Dharmik Thakkar
2019-04-30 11:20 ` Mcnamara, John
2019-04-30 11:20   ` Mcnamara, John
2019-05-04 21:32   ` Thomas Monjalon
2019-05-04 21:32     ` Thomas Monjalon

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