Nicely enough we get the context switch benefit without any cost in the comon case of 64-bit apps.
On September 30, 2014 3:27:41 PM PDT, Thomas Gleixner <t...@linutronix.de> wrote: >On Tue, 30 Sep 2014, Andy Lutomirski wrote: >> It would certainly be possible to clear NT and retry IRET if IRET >> fails with NT set. This would have no overhead for anything >relevant. >> That would be this alternative from my 0/2 email: >> >> - Don't filter NT on sysenter. Instead, filter it on EFI entry >> and modify the IRET code to retry without NT set if NT was set. >> >> Thomas hpa, etc: any thoughts? > >Filter it right away. That's solid and obvious. Anything else is just >complex and prone for future brown paperbag failures. > >We get the context switch benefit from it, so there is some >compensation for the extra cycles. > >Thanks, > > tglx -- Sent from my mobile phone. Please pardon brevity and lack of formatting. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/