From: Jan Beulich <jbeulich@suse.com>
To: Julien Grall <julien@xen.org>
Cc: "Julien Grall" <jgrall@amazon.com>,
"Andrew Cooper" <andrew.cooper3@citrix.com>,
"Roger Pau Monné" <roger.pau@citrix.com>, "Wei Liu" <wl@xen.org>,
xen-devel@lists.xenproject.org
Subject: Re: [PATCH v2 2/2] xen/x86: ioapic: Bail out from timer_irq_works() as soon as possible
Date: Thu, 14 Dec 2023 11:19:15 +0100 [thread overview]
Message-ID: <6c5fd48d-a417-4731-8611-4f5f97865d91@suse.com> (raw)
In-Reply-To: <20231211122322.15815-3-julien@xen.org>
On 11.12.2023 13:23, Julien Grall wrote:
> From: Julien Grall <jgrall@amazon.com>
>
> Currently timer_irq_works() will wait the full 100ms before checking
> that pit0_ticks has been incremented at least 4 times.
>
> However, the bulk of the BIOS/platform should not have a buggy timer.
> So waiting for the full 100ms is a bit harsh.
>
> Rework the logic to only wait until 100ms passed or we saw more than
> 4 ticks. So now, in the good case, this will reduce the wait time
> to ~50ms.
Isn't this more like 40ms (4 ticks 10ms apart)? And really somewhere
between 30 and 40, because the first tick has already partly elapsed?
> Take the opportunity to change the prototype of timer_irq_works() to
> return a bool rather than int (which was already acting as a bool because
> only 0/1 could be returned).
>
> Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Jan
prev parent reply other threads:[~2023-12-14 10:19 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-11 12:23 [PATCH v2 0/2] xen/x86: Optimize timer_irq_works() Julien Grall
2023-12-11 12:23 ` [PATCH v2 1/2] xen/x86: io_apic: Introduce a command line option to skip timer check Julien Grall
2023-12-14 10:10 ` Jan Beulich
2023-12-14 10:14 ` Julien Grall
2023-12-14 10:35 ` Jan Beulich
2024-01-02 19:09 ` Julien Grall
2024-01-04 8:54 ` Jan Beulich
2024-01-15 12:42 ` Roger Pau Monné
2023-12-11 12:23 ` [PATCH v2 2/2] xen/x86: ioapic: Bail out from timer_irq_works() as soon as possible Julien Grall
2023-12-14 10:19 ` Jan Beulich [this message]
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