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Re: [Qemu-devel] [PATCH] KVM: i8254: Clean up limit constant
From: |
Avi Kivity |
Subject: |
Re: [Qemu-devel] [PATCH] KVM: i8254: Clean up limit constant |
Date: |
Mon, 11 Jun 2012 14:18:40 +0300 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 |
On 06/11/2012 01:29 PM, Jan Kiszka wrote:
> On 2012-06-11 12:07, Avi Kivity wrote:
>> On 06/06/2012 05:28 PM, Jan Kiszka wrote:
>>> Due to a offset between the clock used to generate the in-kernel
>>> count_load_time (CLOCK_MONOTONIC) and the clock used for processing this
>>> in userspace (vm_clock), reading back the output of PIT channel 2 via
>>> port 0x61 was broken. One use cases that suffered from it was the CPU
>>> frequency calibration of SeaBIOS, which also affected IDE/AHCI timeouts.
>>>
>>> This fixes it by calibrating the offset between both clocks on
>>> kvm_pit_get and adjusting the kernel value before saving it in the
>>> userspace state. As the calibration only works while the vm_clock is
>>> running, we cache the in-kernel state across stopped phases.
>>
>> Applied, thanks.
>>
>>> + clock_offset = LLONG_MAX;
>>
>> INT64_MAX would me more strictly correct, but in practice it makes no
>> difference.
>
> Was looking for this, just not long enough. Need to print some cheat
> sheet. However, let's clean this up immediately:
>
> ---8<---
>
> clock_offset is int64_t.
>
Thanks, folded.
--
error compiling committee.c: too many arguments to function