Hi, On Thu, Aug 7, 2025 at 3:16 PM Xuneng Zhou <xunengz...@gmail.com> wrote: > > Hi, Tom! > > Thanks for catching this. > > On Thu, Aug 7, 2025 at 2:58 AM Tom Lane <t...@sss.pgh.pa.us> wrote: > > > > Alexander Korotkov <aekorot...@gmail.com> writes: > > > I'm going to push this if no objections. > > > > I looked at these patches while preparing release notes, and > > found an oversight. CheckpointerShmemInit does > > > > CheckpointerShmem->max_requests = Min(NBuffers, > > MAX_CHECKPOINT_REQUESTS); > > > > but CheckpointerShmemSize still does > > > > size = add_size(size, mul_size(NBuffers, sizeof(CheckpointerRequest))); > > > > So if NBuffers is more than MAX_CHECKPOINT_REQUESTS, we will allocate > > extra CheckpointerRequest array entries that we will never use, > > wasting shared memory. Admittedly the amount is small relative to the > > shared buffers themselves, but at the very least this is confusing. > > > > The comment in CheckpointerShmemSize needs adjustment, too. > > I attached a patch to fix it.
Sorry for the error in this patch. I forgot to take the min of NBuffers and MAX_CHECKPOINT_REQUESTS for mem size calculation. Many thanks to Alexander for correcting and pushing it.
