| From: | Ants Aasma <ants(at)cybertec(dot)at> |
|---|---|
| To: | Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> |
| Cc: | Amit Khandekar <amitdkhan(dot)pg(at)gmail(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Andres Freund <andres(at)anarazel(dot)de>, PostgreSQL Hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org> |
| Subject: | Re: spin_delay() for ARM |
| Date: | 2020-04-17 13:59:46 |
| Message-ID: | CANwKhkMRJ2S+9QGWVOVrJ_U5gTYtQQqjue4z1kHUdUUntuFZ0Q@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Thu, 16 Apr 2020 at 10:33, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> wrote:
> what I know, pgbench cannot be used for testing spinlocks problems.
>
> Maybe you can see this issue when a) use higher number clients - hundreds, thousands. Decrease share memory, so there will be press on related spin lock.
There really aren't many spinlocks left that could be tickled by a
normal workload. I looked for a way to trigger spinlock contention
when I prototyped a patch to replace spinlocks with futexes. The only
one that I could figure out a way to make contended was the lock
protecting parallel btree scan. A highly parallel index only scan on a
fully cached index should create at least some spinlock contention.
Regards,
Ants Aasma
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Amit Langote | 2020-04-17 14:58:08 | Re: adding partitioned tables to publications |
| Previous Message | Tom Lane | 2020-04-17 13:59:25 | Re: 001_rep_changes.pl stalls |