On 30/01/2026 11:22, Ashutosh Bapat wrote:
On Thu, Jan 29, 2026 at 9:11 PM Ashutosh Bapat
<[email protected]> wrote:
A nitpick should content_offset be contentOffset (like totalSize) or
content_offset (like dsm_control)? I am ok either way.
Huh, what was I looking at? there is no totalSize in PGShmemHeader.
The new member's name fits the style of other names. Ignore this
comment.
Right. I renamed "freeoffset" to "free_offset", though, since we're
moving it to a different struct anyway.
A minor discomfort I have is ShmemBase, which is the starting address
that the allocator will use, remains outside of ShmemAllocatorData().
But it doesn't change once set so no need to "share" it through the
memory and also that will create a self-referencing pointer within the
shared memory. So it's fine.
I think we can just get rid of ShmemBase and ShmemEnd. Their values
can be derived from other variables at run time as done in the
attached patch (0002). Alternatively, we could add them to
ShmemAllocatorData itself to keep everything related to allocation
together. But it's not really needed.
I wanted to go as far as creating yet another structure to hold
ShmemSegHdr and ShmemAllocator together. Having a structure will help
in the shared buffer resizing project which needs multiple shared
memory segments. But it can wait.
What do you think?
Meh, it doesn't feel much of an improvement to me. You're right that
ShmemBase and ShmemEnd can be derived, but it feels kind of nice to have
them as as explicit variables.
So, pushed just the first patch, thanks!
- Heikki
