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From: Dimitri Sivanich <sivanich@hpe.com>
To: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Jonathan Corbet <corbet@lwn.net>, Steve Wahl <steve.wahl@hpe.com>,
	Justin Ernst <justin.ernst@hpe.com>,
	Kyle Meyer <kyle.meyer@hpe.com>,
	Russ Anderson <russ.anderson@hpe.com>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>
Subject: [PATCH] x86/tsc: Disable clocksource watchdog for TSC on recent UV
Date: Wed, 30 Jul 2025 16:10:57 -0500	[thread overview]
Message-ID: <aIqKYdvlKlBlSoQK@hpe.com> (raw)

Disable clocksource watchdog checking on recent and future UV platforms
to avoid false positives.

Commits 'b50db7095fe0 ("x86/tsc: Disable clocksource watchdog for TSC on
qualified platforms")' and '233756a640be ("Extend watchdog check exemption
to 4-Sockets platform")' were introduced to avoid an issue where the TSC
is falsely declared unstable by exempting qualified platforms of up to
4-sockets from TSC clocksource watchdog checking.  Extend that exemption
to include recent and future UV platforms.

Signed-off-by: Dimitri Sivanich <sivanich@hpe.com>
---
 arch/x86/kernel/tsc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 87e749106dda..23727d7214e6 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -31,7 +31,7 @@
 #include <asm/i8259.h>
 #include <asm/msr.h>
 #include <asm/topology.h>
-#include <asm/uv/uv.h>
+#include <asm/uv/uv_hub.h>
 #include <asm/sev.h>
 
 unsigned int __read_mostly cpu_khz;	/* TSC clocks / usec, not used here */
@@ -1261,7 +1261,7 @@ static void __init check_system_tsc_reliable(void)
 	if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC) &&
 	    boot_cpu_has(X86_FEATURE_NONSTOP_TSC) &&
 	    boot_cpu_has(X86_FEATURE_TSC_ADJUST) &&
-	    topology_max_packages() <= 4)
+	    (topology_max_packages() <= 4 || is_uvy_hub()))
 		tsc_disable_clocksource_watchdog();
 }
 
-- 
2.43.0


             reply	other threads:[~2025-07-30 21:29 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-07-30 21:10 Dimitri Sivanich [this message]
2025-07-31  9:01 ` [PATCH] x86/tsc: Disable clocksource watchdog for TSC on recent UV kernel test robot

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