From: Jan Beulich <jbeulich@suse.com>
To: Frediano Ziglio <frediano.ziglio@cloud.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, Dave Hansen <dave.hansen@linux.intel.com>,
Borislav Petkov <bp@alien8.de>, Ingo Molnar <mingo@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Juergen Gross <jgross@suse.com>,
xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86/xen/time: Reduce Xen timer tick
Date: Mon, 17 Jun 2024 16:22:21 +0200 [thread overview]
Message-ID: <2fe6ef97-84f2-4bf4-870b-b0bb580fa38f@suse.com> (raw)
In-Reply-To: <20240617141303.53857-1-frediano.ziglio@cloud.com>
On 17.06.2024 16:13, Frediano Ziglio wrote:
> Current timer tick is causing some deadline to fail.
> The current high value constant was probably due to an old
> bug in the Xen timer implementation causing errors if the
> deadline was in the future.
> This was fixed in Xen commit:
> 19c6cbd90965 xen/vcpu: ignore VCPU_SSHOTTMR_future
And then newer kernels are no longer reliably usable on Xen older than
this?
> --- a/arch/x86/xen/time.c
> +++ b/arch/x86/xen/time.c
> @@ -30,7 +30,7 @@
> #include "xen-ops.h"
>
> /* Minimum amount of time until next clock event fires */
> -#define TIMER_SLOP 100000
> +#define TIMER_SLOP 1000
It may be just the lack of knowledge of mine towards noadays's Linux'es
time handling, but the change of a value with this name and thus
commented doesn't directly relate to "timer tick" rate. Could you maybe
help me see the connection?
Jan
next prev parent reply other threads:[~2024-06-17 14:22 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-17 14:13 [PATCH] x86/xen/time: Reduce Xen timer tick Frediano Ziglio
2024-06-17 14:22 ` Jan Beulich [this message]
2024-06-17 14:37 ` Roger Pau Monné
2024-06-18 8:37 ` Frediano Ziglio
2024-06-18 8:57 ` Roger Pau Monné
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