On Fri, Dec 01, 2017 at 05:58:45PM +0000, Dave Martin wrote: > +1, at least for arm64. I don't see a really compelling reason for > holding kernel-mode NEON around memory management now that we have a > strict save-once-restore-lazily model. > > This may not work so well for arm though -- I haven't looked at that > code for a while. > > > If there is memory manamement in any core loop, you already lost > the performance battle, and an extra > kernel_neon_end()+kernel_neon_begin() may not be that catastrophic. Remember that we don't permit context switches while kernel neon is in use on ARM - if there's any possibility of scheduling to occur, the get_cpu() in kernel_neon_begin() should trigger a schedule-while- atomic warning. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up According to speedtest.net: 8.21Mbps down 510kbps up -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
