Re: Add CHECKPOINT_REQUESTED flag to the log message in LogCheckpointStart()

On Wed, Mar 2, 2022 at 5:41 PM Nitin Jadhav
<nitinjadhavpostgres(at)gmail(dot)com> wrote:
>
> Hi,
>
> I have noticed that the CHECKPOINT_REQUESTED flag information is not
> present in the log message of LogCheckpointStart() function. I would
> like to understand if it was missed or left intentionally. The log
> message describes all the possible checkpoint flags except
> CHECKPOINT_REQUESTED flag. I feel we should support this. Thoughts?

I don't think that's useful. Being in LogCheckpointStart
(CreateCheckPoint or CreateRestartPoint) itself means that somebody
has requested a checkpoint. Having CHECKPOINT_REQUESTED doesn't add
any value.

I would suggest removing the CHECKPOINT_REQUESTED flag as it's not
being used anywhere instead CheckpointerShmem->ckpt_flags is used as
an indication of the checkpoint requested in CheckpointerMain [1]. If
others don't agree to remove as it doesn't cause any harm, then, I
would add something like this for more readability:

if ((((volatile CheckpointerShmemStruct *)
CheckpointerShmem)->ckpt_flags) & CHECKPOINT_REQUESTED))
{
do_checkpoint = true;
PendingCheckpointerStats.m_requested_checkpoints++;
}

[1]
/*
* Detect a pending checkpoint request by checking whether the flags
* word in shared memory is nonzero. We shouldn't need to acquire the
* ckpt_lck for this.
*/
if (((volatile CheckpointerShmemStruct *)
CheckpointerShmem)->ckpt_flags)
{
do_checkpoint = true;
PendingCheckpointerStats.m_requested_checkpoints++;
}

Regards,
Bharath Rupireddy.