[Devel] [PATCH rh7 1/2] vdso: virtualized monotonic gettime through vdso

[Andrey Ryabinin]

On 05/24/2017 07:38 PM, Dmitry Safonov wrote:
> On 05/24/2017 07:34 PM, Andrey Ryabinin wrote:
>>
>>
>> On 05/24/2017 07:29 PM, Dmitry Safonov wrote:
>>> On 05/24/2017 06:21 PM, Andrey Ryabinin wrote:
>>>> We already have infrastructure for virtualized vdso, however we use
>>>> it only to change LINUX_VERSION_NAME in container. Simply store container's
>>>> start time - ve->start_timespec in vdso variable - VDSO64_ve_start_timespec,
>>>> and use it in __vdso_clock_gettime() to calculate container's monotonic time.
>>>>
>>>> Make uts_arch_setup_additional_pages()/uts_prep_vdso_pages_locked() to always
>>>> setup new vdso, since previous policy to setup vdso only if uts_ns->name.release
>>>> wouldn't work for virtualized __vdso_clock_gettime()
>>>>
>>>> https://jira.sw.ru/browse/PSBM-66451
>>>> Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
>>>
>>> Well, that's all looks good, but I've two questions:
>>>
>>> 1. Where VDSO64_ve_start_timespec is set? I do not see that part.
>>>
>>
>> in uts_arch_setup_additional_pages() and uts_prep_vdso_pages_locked()
> 
> Uhm, yes, but that means that ve_ts_write() is broken for
> running CT.
> 

Do we care? Changing monotonic time on the fly doesn't sound like a brilliant idea.