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charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The 06/28/2021 11:17, Will Deacon wrote: > On Fri, Jun 25, 2021 at 03:14:40PM +0100, Szabolcs Nagy wrote: > > i think a user should be able to ask for sync check > > mode for a process and get an error if that's not > > possible. > > Hmm. The question then is what do we do if the sysfs override is changed > after the application has started running? if the failure cannot be reported then i think it is not ok to override. at least running a process in sync mode sounds useful to me. with the per cpu override this may need privilege and even then it may not be possible without significantly affecting other processes. and sysfs is not a reliable api to figure out what's going on. if we need the ability to completely disable sync mode on a cpu (as opposed to just doing it for performance tuning) then it can be a boot option, or processes that requested guaranteed sync mode can be killed. i'm not against per cpu setting since most code should work with whatever tag check mode, but if we make that the abi (that code should work in whatever mode) then i think we weaken the usability of mte. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel