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From: Stephen Hemminger <stephen@networkplumber.org>
To: "Mattias Rönnblom" <hofors@lysator.liu.se>
Cc: dev@dpdk.org, "Mattias Rönnblom" <mattias.ronnblom@ericsson.com>,
	"Bruce Richardson" <bruce.richardson@intel.com>
Subject: Re: [PATCH v2 2/2] random: make rte_rand() thread safe for non-EAL threads
Date: Fri, 8 Sep 2023 13:56:02 -0700	[thread overview]
Message-ID: <20230908135602.4a9026c0@hermes.local> (raw)
In-Reply-To: <136fb174-ca02-577e-e690-f770a0328f10@lysator.liu.se>

On Fri, 8 Sep 2023 22:48:54 +0200
Mattias Rönnblom <hofors@lysator.liu.se> wrote:

> On 2023-09-07 17:24, Stephen Hemminger wrote:
> > Add missing locking so that if two non-EAL threads call rte_rand()
> > they will not corrupt the per-thread state.
> > 
> > Fixes: 3f002f069612 ("eal: replace libc-based random generation with LFSR")  
> 
> The API documentation clearly states that no MT safety guarantees are 
> given for unregistered non-EAL threads. So this patch doesn't fix anything.
> 
> rte_rand() is MT safe for *registered* non-EAL threads.

Reading the documentation, it only guarantees safety if registered.
We should add an otherwise clause rather than leaving case as undefined.

  reply	other threads:[~2023-09-08 20:56 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-09-06 15:53 [PATCH] random: initialize the random state for non-eal lcores Stephen Hemminger
2023-09-06 16:25 ` Morten Brørup
2023-09-06 16:28 ` Stephen Hemminger
2023-09-07 15:24 ` [PATCH v2 0/2] fixes to rte_random for non-EAL threads Stephen Hemminger
2023-09-07 15:24   ` [PATCH v2 1/2] random: initialize the random state " Stephen Hemminger
2023-10-02  9:00     ` Morten Brørup
2023-10-02 12:27     ` Mattias Rönnblom
2023-10-02 16:07       ` Stephen Hemminger
2023-10-04  8:45       ` David Marchand
2023-09-07 15:24   ` [PATCH v2 2/2] random: make rte_rand() thread safe " Stephen Hemminger
2023-09-07 15:47     ` Stephen Hemminger
2023-09-07 16:10       ` David Marchand
2023-09-08 20:48     ` Mattias Rönnblom
2023-09-08 20:56       ` Stephen Hemminger [this message]
2023-09-09  7:00         ` Mattias Rönnblom
2023-10-02 16:10     ` Stephen Hemminger

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