> Date: Tue, 29 Jan 2019 12:07:48 +0100 > From: Alex Holst <[email protected]> > > Quoting Mark Kettenis ([email protected]): > > > > > > Hi. It turns out there is a hard cap which might be worth documenting. > > > > That isn't true. > > I'm just informed the buffer cache limit is an amd64, arm64 and 32-bit > archs thing.
arm64 doesn't have a limit. > sparc64 appears to have no such limit. Do you know the details of other > architectures / environments? alpha doesn't have the limit either, and in theory some sgi machines are fine as well. An accurate description would be that the percentage is actually the percentage of "DMA-reachable" physical memory the buffer cache may use. The minimum percentage is 5% and the maximum is 90%. But documenting it like that needs an explanation of what "DMA-reachable" memory is. Cheers, Mark
