Re: [PATCH v7] posix-timers: add clock_compare system call

From: Mahesh Bandewar (महेश बंडेवार)
Date: Tue Apr 02 2024 - 17:17:26 EST


On Tue, Apr 2, 2024 at 2:25 AM Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
>
> On Mon, Apr 01 2024 at 22:42, Mahesh Bandewar (महेश बंडेवार) wrote:
> > On Mon, Apr 1, 2024 at 1:46 PM Thomas Gleixner <tglx@linutronixde> wrote:
> >> So if there is a backwards compability issue with PTP_SYS_OFFSET2, then
> >> you need to introduce PTP_SYS_OFFSET3. The PTP_SYS_*2 variants were
> >> introduced to avoid backwards compatibility issues as well, but
> >> unfortunately that did not address the reserved fields problem for
> >> PTP_SYS_OFFSET2. PTP_SYS_OFFSET_EXTENDED2 should just work, but maybe
> >> the PTP maintainers want a full extension to '3'. Either way is fine.
> >>
> > https://patchwork.kernel.org/project/netdevbpf/patch/20240104212436.3276057-1-maheshb@xxxxxxxxxx/
> >
> > This was my attempt to solve a similar issue with the new ioctl op to
> > avoid backward compatibility issues. Instead of flags I used the
> > clockid_t in a similar fashion.
>
> Works as well. I'm not seing the point for CLOCK_MONOTONIC and the
> change logs are not really telling anything about the problem being
> solved....
>
https://lore.kernel.org/lkml/20240104212431.3275688-1-maheshb@xxxxxxxxxx/T/#:~:text=*%20[PATCHv3%20net%2Dnext%200/3]%20add%20ptp_gettimex64any()%20API,21:24%20Mahesh%20Bandewar%200%20siblings%2C%200%20replies;

This is the cover letter where I tried to explain the need for this.

Granted, my current use case is for CLOCK_MONOTONIC_RAW but just
because I don't have a use case doesn't mean someone else may not have
it and hence added it. In either way it's just a matter of
adding/removing another flag/clock-id.

Thanks,
--mahesh..
> Thanks,
>
> tglx