Hi, On Tue, Jun 24, 2025 at 05:30:02PM +0200, Christoph Berg wrote: > Re: Tomas Vondra > > If it's a reliable fix, then I guess we can do it like this. But won't > > that be a performance penalty on everyone? Or does the system split the > > array into 16-element chunks anyway, so this makes no difference? > > There's still the overhead of the syscall itself. But no idea how > costly it is to have this 16-step loop in user or kernel space. > > We could claim that on 32-bit systems, shared_buffers would be smaller > anyway, so there the overhead isn't that big. And the step size should > be larger (if at all) on 64-bit.
Right, and we already mention in the doc that using those views is "very slow" or "can take a noticeable amount of time". > > Anyway, maybe we should start by reporting this to the kernel people. Do > > you want me to do that, or shall one of you take care of that? I suppose > > that'd be better, as you already wrote a fix / know the code better. > > Submitted: https://marc.info/?l=linux-mm&m=175077821909222&w=2 Thanks! I had in mind to look at how to report such a bug and provide a patch but you beat me to it. Regards, -- Bertrand Drouvot PostgreSQL Contributors Team RDS Open Source Databases Amazon Web Services: https://aws.amazon.com
