Hi, On 2023-06-21 09:35:36 +0700, John Naylor wrote: > On Wed, Jun 21, 2023 at 12:46 AM Andres Freund <and...@anarazel.de> wrote: > > > > Hi, > > > > On 2023-06-20 10:29:41 -0700, Andres Freund wrote: > > > On 2023-06-20 10:23:14 +0700, John Naylor wrote: > > > > Here's a start at that, trying with postmaster only. Unfortunately, I > get > > > > "MADV_COLLAPSE failed: Invalid argument". > > > > > > I also see that. But depending on the steps, I also see > > > MADV_COLLAPSE failed: Resource temporarily unavailable > > > > > > I suspect there's some kernel issue. I'll try to ping somebody. > > > > Which kernel version are you using? It looks like the issue I am hitting > might > > be specific to the in-development 6.4 kernel. > > (Fedora 38) uname -r shows > > 6.3.7-200.fc38.x86_64
FWIW, I bisected the bug I was encountering. As far as I understand, it should not affect you, it was only merged into 6.4-rc1 and a fix is scheduled to be merged into 6.4 before its release. See https://lore.kernel.org/all/ZJIWAvTczl0rHJBv@x1n/ So I am wondering if you're encountering a different kind of problem. As I mentioned, I have observed that the pages need to be clean for this to work. For me adding a "sync path/to/postgres" makes it work on 6.3.8. Without the sync it starts to work a while later (presumably when the kernel got around to writing the data back). without sync: self: 0x563b2abf0a72 start: 563b2a800000 end: 563b2afe3000 old advlen: 7e3000 new advlen: 800000 MADV_COLLAPSE failed: Invalid argument with sync: self: 0x555c947f0a72 start: 555c94400000 end: 555c94be3000 old advlen: 7e3000 new advlen: 800000 Greetings, Andres Freund