From: Stephen Hemminger <stephen@networkplumber.org>
To: Isaac Boukris <iboukris@gmail.com>
Cc: users@dpdk.org
Subject: Re: Accuracy of rte_get_tsc_hz() compared to linux
Date: Thu, 19 Sep 2024 15:02:38 -0700 [thread overview]
Message-ID: <20240919150238.27b985e6@hermes.local> (raw)
In-Reply-To: <CAC-fF8TBY03BDgUaTgL5Qn4G9q134hh8cZR89SQ=ifL+YhCM9g@mail.gmail.com>
On Thu, 19 Sep 2024 01:04:40 +0300
Isaac Boukris <iboukris@gmail.com> wrote:
> Hi,
>
> On Intel(R) Xeon(R) Gold 6130 CPU @ 2.10GHz (see lscpu output at the end).
>
> The rte_get_tsc_hz() returns 2100000 KHz but using it causes our
> timestamps to lag behind real time (roughly a sec per 10 min). I
> noticed the kernel uses 2095082 KHz and in fact it gives much better
> results.
>
> dmesg:
> tsc: Detected 2095.082 MHz processor
>
> tsc_freq_khz (custom kmod to exposes kernel's tsc_khz):
> cat /sys/devices/system/cpu/cpu0/tsc_freq_khz
Rather going off into all the weeds of cpuid and whether
the value reported is correct. Perhaps DPDK should just look at the
kernel sysfs files??
next prev parent reply other threads:[~2024-09-19 22:02 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-18 22:04 Isaac Boukris
2024-09-18 23:27 ` Stephen Hemminger
2024-09-19 9:37 ` Isaac Boukris
2024-09-19 12:26 ` Isaac Boukris
2024-09-19 13:04 ` Isaac Boukris
2024-09-19 18:33 ` Isaac Boukris
2024-09-19 21:53 ` Stephen Hemminger
2024-09-19 22:02 ` Stephen Hemminger [this message]
2024-09-19 22:21 ` Stephen Hemminger
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