On 5/15/20 6:16 PM, Catalin Marinas wrote: > For performance analysis it may be desirable to disable MTE altogether > via an early param. Introduce arm64.mte_disable and, if true, filter out > the sanitised ID_AA64PFR1_EL1.MTE field to avoid exposing the HWCAP to > user. > > Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx> > Cc: Will Deacon <will@xxxxxxxxxx> > --- > > Notes: > New in v4. > > Documentation/admin-guide/kernel-parameters.txt | 4 ++++ > arch/arm64/kernel/cpufeature.c | 11 +++++++++++ > 2 files changed, 15 insertions(+) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index f2a93c8679e8..7436e7462b85 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -373,6 +373,10 @@ > arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards > Format: <io>,<irq>,<nodeID> > > + arm64.mte_disable= > + [ARM64] Disable Linux support for the Memory > + Tagging Extension (both user and in-kernel). > + Should it really to take parameter (on/off/true/false)? It may lead to expectation that arm64.mte_disable=false should enable MT and, yes, double negatives make it look ugly, so if we do need parameter, can it be arm64.mte=on/off/true/false? Cheers Vladimir