Re: [PATCH v5 5/5] xen/console: Traditional console timestamps including milliseconds

[David Vrabel <david.vrabel@citrix.com>]

On 11/03/14 10:55, Andrew Cooper wrote:
> On 11/03/14 10:13, Ian Campbell wrote:
>> On Fri, 2014-03-07 at 17:28 +0000, Andrew Cooper wrote:
>>> Suggested-by: Don Slutz <dslutz@verizon.com>
>>> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
>>> CC: Keir Fraser <keir@xen.org>
>>> CC: Jan Beulich <JBeulich@suse.com>
>>> CC: Ian Campbell <ian.campbell@citrix.com>
>>> CC: Stefano Stabellini <stefano.stabellini@citrix.com>
>>> CC: Tim Deegan <tim@xen.org>
>>>
>>> ---
>>>
>>> The change in arm is only for the sake of compilation - the function is a
>>> no-op.
>> Acked-by: Ian Campbell <ian.campbell@citrix.com>
>>
>>> v5: Correct check for null in wallclock_time()
>>> ---
>>>  docs/misc/xen-command-line.markdown |    4 +++-
>>>  xen/arch/arm/time.c                 |    2 +-
>>>  xen/arch/x86/time.c                 |   10 +++++++---
>>>  xen/drivers/char/console.c          |   11 ++++++++++-
>>>  xen/include/xen/time.h              |    2 +-
>>>  5 files changed, 22 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/docs/misc/xen-command-line.markdown b/docs/misc/xen-command-line.markdown
>>> index e437091..ced5eca 100644
>>> --- a/docs/misc/xen-command-line.markdown
>>> +++ b/docs/misc/xen-command-line.markdown
>>> @@ -275,7 +275,7 @@ cleared.  This allows a single port to be shared by two subsystems
>>>  makes sense on its own.
>>>  
>>>  ### console\_timestamps
>>> -> `= none | date | boot`
>>> +> `= none | date | datems | boot`
>> I think someone (David V?) asked this earlier but I don't remember a
>> response: Why do we need to support multiple timestamp formats? Can't we
>> just pick one which has reasonable accuracy/information content and
>> stick with it?
>>
>> Ian.
>>
> 
> That is posed as an RFC in patch 0, which has gone without comment for
> several versions of this series now.
> 
> XenServer has timestamps enabled by default, and in my opinion is too
> long (space wise) and insufficiently precise.  That is why I introduced
> the linux-style timestamps.
> 
> Don has expressed interest in keeping the existing format, preferring it
> to linux-style.  Furthermore, the precision issue has been addressed, at
> the expense of extra length, space wise.

Wallclock date/time timestamps may be better served by a klogd like
logging daemon in dom0 (but such a daemon doesn't exist yet).

David