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

From: Thomas Gleixner <[email-masked]>
Date: Wed, 03 Apr 2024 00:37:28 +0200

On Tue, Apr 02 2024 at 14:16, Mahesh Bandewar (महेश बंडेवार) wrote:
> On Tue, Apr 2, 2024 at 2:25 AM Thomas Gleixner <[email-masked]> wrote:
>> 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/[email-masked]/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.

The justification for a patch needs to be in the change log and not in
the cover letter because the cover letter is not part of the git
history.

> 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.

Then why did you not five other clock IDs? Someone else might have a
use case, no?

While a syscall/ioctl should be flexible for future use, the kernel does
not add features just because there might be some use case. It's
documented how this works.

Thanks,

        tglx