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 15:21:48 -0700 [thread overview]
Message-ID: <20240919152148.45a19343@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
> 2095082
Sigh. exposing tsc frequency through sysfs is a Redhat extension
that never got merged upstream.
prev parent reply other threads:[~2024-09-19 22:21 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
2024-09-19 22:21 ` Stephen Hemminger [this message]
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