21–30 of 177 posts
Its worth reading this follow-up LKML post by Andres Freund (who works on Postgres): https://lore.kernel.org/lkml/yr3inlzesdb45n6i6lpbimwr7b25kqk...
Earlier quoted context omitted.
> Nobody sensible runs the latest kernel From the article: "Linux 7.0 stable is due out in about two weeks. This is also the kernel version powering Ubuntu 26.04 LTS to be released later in April." Unfortunately, lots of people will be running it in less than a month. At the moment, it'll take a kernel patch (not a sysctl) to undo this-- hopefully something changes.
Not nobody but not everybody upgrades to the newest distros immediately. That's the advantage of LTS. I've even found that a lot of programs have poorer support on 24.04 than 22.04 due to security changes, so I'm fine sticking with 22.04 as my main dev system.
While that's true, for new deployments the story is often "deploy on the latest release of things available at the time".
So, there will probably be a substantial deployment of new projects / testing projects using the Linux 7.0 kernel along with the latest available software packages in a few weeks.
Earlier quoted context omitted.
> Nobody sensible runs the latest kernel From the article: "Linux 7.0 stable is due out in about two weeks. This is also the kernel version powering Ubuntu 26.04 LTS to be released later in April." Unfortunately, lots of people will be running it in less than a month. At the moment, it'll take a kernel patch (not a sysctl) to undo this-- hopefully something changes.
Not nobody but not everybody upgrades to the newest distros immediately. That's the advantage of LTS. I've even found that a lot of programs have poorer support on 24.04 than 22.04 due to security changes, so I'm fine sticking with 22.04 as my main dev system.
Its worth reading this follow-up LKML post by Andres Freund (who works on Postgres): https://lore.kernel.org/lkml/yr3inlzesdb45n6i6lpbimwr7b25kqk...
AIUI in that thread they're saying "0.51x" the perf on a 96-core arm64 machine and they're also saying they cannot reproduce it on a 96-core amd64 machine. So it's not going to affect everybody both running PostgreSQL and upgrading to the latest kernel. Conditions seems to be: arm64, shitloads of core, kernel 7.0, current version of PostgreSQL. That is not going to be 100% of the installed PostgreSQL DBs out there in…
If someone is running postgres in a serious backend environment, i doubt they are using Ubuntu or even touching 7.x for months (or years). It’ll be some flavor of Debian or Red Hat still on 6.x (maybe even 5?). Those same users won’t touch 7.x until there has been months of testing by distros.
Its worth reading this follow-up LKML post by Andres Freund (who works on Postgres): https://lore.kernel.org/lkml/yr3inlzesdb45n6i6lpbimwr7b25kqk...
I feel like using spinlocks in user space at all without kernel support like rseq is just asking for weird performance degradations.
Yeah, exactly. "Doctor, help, somebody replaced my wooden hammer with a metal one, and now I can't hit myself in the face with it as many times."
If you use spinlocks in userspace, you're gonna have a bad time.
Earlier quoted context omitted.
Not nobody but not everybody upgrades to the newest distros immediately. That's the advantage of LTS. I've even found that a lot of programs have poorer support on 24.04 than 22.04 due to security changes, so I'm fine sticking with 22.04 as my main dev system.
That's the advantage of LTS? 24.04 is the LTS, not the one you use, 22.04.
Earlier quoted context omitted.
Not nobody but not everybody upgrades to the newest distros immediately. That's the advantage of LTS. I've even found that a lot of programs have poorer support on 24.04 than 22.04 due to security changes, so I'm fine sticking with 22.04 as my main dev system.
That's the advantage of LTS? 24.04 is the LTS, not the one you use, 22.04.
https://ubuntu.com/about/release-cycle
We're just now looking at moving production machines to 24.04.
It's not a good look to break userspace applications without a deprecation period where both old and new solutions exist, allowing for a transition period.
Nobody sensible runs the latest kernel; nobody running PG in production should be afraid of setting a non-default at either boot time or as a sysctl. So this will, most likely, be another step in building a PG database server (turn off pre-emption if your kernel is 7.0 or later and PG is pre-whatever-version). At worst it might become a permanent part of building a PG server and a FAQ... but if it affects one thing t…