Re: DSA failed to allocate memory

On Fri, Mar 18, 2022 at 3:30 PM Dongming Liu <ldming101(at)gmail(dot)com> wrote:

> So it's OK for a segment to be in a bin that suggests that it has more
>> consecutive free pages than it really does. But it's NOT ok for a
>> segment to be in a bin that suggests it has fewer consecutive pages
>> than it really does. If dsa_free() is putting things back into the
>> wrong place, that's what we need to fix.
>
>
> I'm trying to move segments into appropriate bins in dsa_free().
> In 0001-Re-bin-segment-when-dsa-memory-is-freed.patch, I extract
> the re-bin segment logic into a separate function called rebin_segment,
> call it to move the segment to the appropriate bin when dsa memory is
> freed. Otherwise, when allocating memory, due to the segment with
> enough contiguous pages is in a smaller bin, a suitable segment
> may not be found to allocate memory.
>
> Fot test, I port the test_dsa patch from [1] and add an OOM case to
> test memory allocation until OOM, free and then allocation, compare
> the number of allocated memory before and after.
>
> Any thoughts?
>
> [1]
> https://www.postgresql.org/message-id/CAEepm%3D3U7%2BRo7%3DECeQuAZoeFXs8iDVX56NXGCV7z3%3D%2BH%2BWd0Sw%40mail.gmail.com
>
>
Fix rebin_segment not working on in-place dsa.

--
Best Regards,
Dongming