Re: [PATCH] ARM: mm: Fix ARCH_LOW_ADDRESS_LIMIT when CONFIG_ZONE_DMA
From: "Russell King (Oracle)" <linux@armlinux.org.uk>
Date: 2023-06-03 12:39:07
On Sat, Jun 03, 2023 at 02:33:49PM +0200, Arnd Bergmann wrote:
Changing the low address limit by itself makes the swiotlb work correctly, but for performance we also want to avoid having to use the swiotlb at all when dealing with the zero page.
How often is the zero page used for DMA _to_ a device (it should never be used for DMA _from_ a device.) ? It doesn't sound that useful to me, since it can only be used for writing zeros. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel