patch 'eal/x86: fix TSC frequency query' has been queued to stable release 25.11.1

Kevin Traynor ktraynor at redhat.com
Thu Feb 26 14:08:53 CET 2026


Hi,

FYI, your patch has been queued to stable release 25.11.1

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 03/02/26. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/kevintraynor/dpdk-stable

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable/commit/02c2fe82aba3847a534062c220b4c1a106dbc256

Thanks.

Kevin

---
>From 02c2fe82aba3847a534062c220b4c1a106dbc256 Mon Sep 17 00:00:00 2001
From: Thomas Monjalon <thomas at monjalon.net>
Date: Fri, 30 Jan 2026 17:50:53 +0100
Subject: [PATCH] eal/x86: fix TSC frequency query

[ upstream commit a17499cf33a1606731d75d15a18bfd42c497b40e ]

After getting TSC information from cpuid instruction,
some values must be multiplied and divided.
We must multiply first to get the most accurate value.

Example:
	before: 1000000000 * (23 / 10) = 2 GHz
	after:  1000000000 * 23 / 10 = 2.3 GHz

Bugzilla ID: 1869
Fixes: ad3516bb4ae1 ("eal/x86: implement arch-specific TSC freq query")

Reported-by: Luigi Rizzo <rizzo.unipi at gmail.com>
Signed-off-by: Thomas Monjalon <thomas at monjalon.net>
Reviewed-by: Stephen Hemminger <stephen at networkplumber.org>
---
 .mailmap                 | 1 +
 lib/eal/x86/rte_cycles.c | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/.mailmap b/.mailmap
index 98d9058267..961b20e84e 100644
--- a/.mailmap
+++ b/.mailmap
@@ -933,4 +933,5 @@ Luca Boccassi <luca.boccassi at microsoft.com> <lboccass at brocade.com>
 Luca Boccassi <luca.boccassi at microsoft.com> <luca.boccassi at intl.att.com>
 Luca Vizzarro <luca.vizzarro at arm.com>
+Luigi Rizzo <rizzo.unipi at gmail.com>
 Luka Jankovic <luka.jankovic at ericsson.com>
 Lukas Sismis <sismis at dyna-nic.com> <sismis at cesnet.cz>
diff --git a/lib/eal/x86/rte_cycles.c b/lib/eal/x86/rte_cycles.c
index f147a5231d..e8e805e710 100644
--- a/lib/eal/x86/rte_cycles.c
+++ b/lib/eal/x86/rte_cycles.c
@@ -146,5 +146,5 @@ get_tsc_freq_arch(void)
 		/* EBX : TSC/Crystal ratio, ECX : Crystal Hz */
 		if (b && c)
-			return c * (b / a);
+			return (uint64_t)c * b / a;
 	}
 
-- 
2.53.0

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2026-02-26 10:16:49.117365800 +0000
+++ 0051-eal-x86-fix-TSC-frequency-query.patch	2026-02-26 10:16:46.967459308 +0000
@@ -1 +1 @@
-From a17499cf33a1606731d75d15a18bfd42c497b40e Mon Sep 17 00:00:00 2001
+From 02c2fe82aba3847a534062c220b4c1a106dbc256 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit a17499cf33a1606731d75d15a18bfd42c497b40e ]
+
@@ -16 +17,0 @@
-Cc: stable at dpdk.org
@@ -27 +28 @@
-index 67183b09e5..4b7e3b9eb0 100644
+index 98d9058267..961b20e84e 100644



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