> On Mon, 13 Aug 2018 at 17:36, Alexander Korotkov <
a.korot...@postgrespro.ru> wrote:
>
> 2) lwlock-far-2.patch
> New flag LW_FLAG_FAIR is introduced. This flag is set when first
> shared locker in the row releases the lock. When LW_FLAG_FAIR is set
> and there is already somebody in the queue,
> On Mon, 13 Aug 2018 at 17:36, Alexander Korotkov
> wrote:
>
> Hi!
>
> I run pgbench (read-write and read-only benchmarks) on Amazon
> c5d.18xlarge virtual machine, which has 72 VCPU (approximately same
> power as 36 physical cores). The results are attached
> (lwlock-fair-ro.png and
Hi!
This subject was already raised multiple times [1], [2], [3]. In
short, our LWLock implementation has pathological behavior when shared
lockers constitute a continuous flood. In this case exclusive lock
waiters are not guaranteed to eventually get the lock. When shared
lock is held, other
