739003c642
We don't need to check for MTE support before checking the flag because it can only be set if the hardware supports MTE. As a result we can unconditionally check the flag bit which is expected to be in a register and therefore the check can be done in a single instruction instead of first needing to load the hwcaps. On a DragonBoard 845c with a kernel built with CONFIG_ARM64_MTE=y with the powersave governor this reduces the cost of a kernel entry/exit (invalid syscall) from 465.1ns to 463.8ns. Signed-off-by: Peter Collingbourne <pcc@google.com> Link: https://linux-review.googlesource.com/id/If4dc3501fd4e4f287322f17805509613cfe47d24 Link: https://lore.kernel.org/r/20201118032051.1405907-1-pcc@google.com [catalin.marinas@arm.com: remove IS_ENABLED(CONFIG_ARM64_MTE)] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> |
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boot | ||
configs | ||
crypto | ||
include | ||
kernel | ||
kvm | ||
lib | ||
mm | ||
net | ||
xen | ||
Kbuild | ||
Kconfig | ||
Kconfig.debug | ||
Kconfig.platforms | ||
Makefile |