From: "Mattias Rönnblom" <mattias.ronnblom@ericsson.com>
To: Tonghao Zhang <xiangxia.m.yue@gmail.com>,
Stephen Hemminger <stephen@networkplumber.org>
Cc: dpdk-dev <dev@dpdk.org>, "stable@dpdk.org" <stable@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH dpdk-dev] rte_random: fix crash when random init
Date: Tue, 14 Apr 2020 13:19:49 +0000 [thread overview]
Message-ID: <e98b60ee-20be-ac9e-2eaa-e1b3a670adf1@ericsson.com> (raw)
In-Reply-To: <CAMDZJNWKd7fs_+i6YpiMK2fufHZShP3W=54hFerC1dWw9eEsCg@mail.gmail.com>
On 2020-04-14 06:43, Tonghao Zhang wrote:
> On Tue, Apr 14, 2020 at 12:07 PM Stephen Hemminger
> <stephen@networkplumber.org> wrote:
>> On Sun, 12 Apr 2020 16:27:53 +0800
>> xiangxia.m.yue@gmail.com wrote:
>>
>>> From: Tonghao Zhang <xiangxia.m.yue@gmail.com>
>>>
>>> When rte_rand_init is invoked, and the kernel
>>> (kernel version < 3.17) running dpdk does't support
>>> *getentropy, at the same time, the cpu does't support
>>> rdseed, the rte_rand_init will invoke rte_get_timer_cycles
>>> which function will invoke rte_get_hpet_cycles
>>> (RTE_LIBEAL_USE_HPET was enabled) while *eal_hpet is not
>>> allocated.
>>>
>>> Fixes: faf8fd252785 ("eal: improve entropy for initial PRNG seed")
>>> Fixes: 3f002f069612 ("eal: replace libc-based random generation with LFSR")
>>>
>>> Cc: stable@dpdk.org
>>>
>>> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
>> Are you sure this patch won't change current default to use HPET (which is slower)?
> In rte_eal_timer_init (linux/eal_timer.c)， it will set
> eal_timer_source = EAL_TIMER_TSC too.
> So after rte_eal_init, eal_timer_source == EAL_TIMER_TSC which is the
> default timer source actually.
> Then this patch will affect RTE_INIT function which invoke
> rte_get_timer_cycles. but hpet is not available yet.
Would using rte_rdtsc() directly be an option?
>> Before this patch users would get TSC as default.
>
>
next prev parent reply other threads:[~2020-04-14 13:19 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-12 8:27 xiangxia.m.yue
2020-04-14 4:06 ` Stephen Hemminger
2020-04-14 4:43 ` Tonghao Zhang
2020-04-14 13:19 ` Mattias Rönnblom [this message]
2020-04-14 13:35 ` David Marchand
2020-04-14 15:37 ` Mattias Rönnblom
2020-04-14 23:42 ` Tonghao Zhang
2020-04-15 6:01 ` Mattias Rönnblom
2020-04-15 8:10 ` David Marchand
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