Обсуждение: Add CHECK_FOR_INTERRUPTS in Evict{Rel,All}UnpinnedBuffers

The pg_buffercache_evict_{relation,all} operations can become extremely
slow when dealing with large buffer pools containing many dirty buffers.
This commit adds CHECK_FOR_INTERRUPTS calls within the underlying
Evict{Rel,All}UnpinnedBuffers functions to ensure these operations
cancellable.

And this should be backpatched through v18 where
pg_buffercache_evict_{relation,all} operations are introduced.

On Sun, Nov 2, 2025 at 6:15 PM 邱宇航 <iamqyh@gmail.com> wrote:
>
> The pg_buffercache_evict_{relation,all} operations can become extremely
> slow when dealing with large buffer pools containing many dirty buffers.
> This commit adds CHECK_FOR_INTERRUPTS calls within the underlying
> Evict{Rel,All}UnpinnedBuffers functions to ensure these operations
> cancellable.
>
> And this should be backpatched through v18 where
> pg_buffercache_evict_{relation,all} operations are introduced.

Commit eab9e4e27c0c added CFI for pg_buffercache functions such as
pg_buffercache_pages, but it seems not to cover
pg_buffercache_evict_relation() and pg_buffercache_evict_all().
EvictRelUnpinnedBuffers() and EvictAllUnpinnedBuffers() are used only
by pg_buffercache and they are for testing/development use, so it
makes sense to add CFI to these functions as well. I'll push the patch
barring any objections.

Regards,

--
Masahiko Sawada
Amazon Web Services: https://aws.amazon.com