Re: [PATCH 1/2] bitmap: add sanity check function for find_bit()
From: "Russell King (Oracle)" <linux@armlinux.org.uk>
Date: 2022-10-25 18:26:44
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On Tue, Oct 25, 2022 at 10:11:51AM -0700, Yury Norov wrote:
ARMv6 may or may not support unaligned access depending on SCTLR.U bit. This is what Russell was concerned about in the other email. As far as I understand, linux enables that feature.
However, we still support ARMv5 and ARMv4, both of which _trap_ every unaligned access, which will make a findbit call with an unaligned pointer using word loads painfully expensive. This is the main reason we haven't used word loads in the findbit ops. As mentioned, I have patches that do change that (and convert the thing to use assembly macros to make updates much easier.) -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps 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