Kevin Hilman <khil...@linaro.org> writes: > commit 91d1aa43 (context_tracking: New context tracking susbsystem) > generalized parts of the RCU userspace extended quiescent state into > the context tracking subsystem. Context tracking is then used > to implement adaptive tickless (a.k.a extended nohz) > > To support the new context tracking subsystem on ARM, the user/kernel > boundary transtions need to be instrumented. > > For exceptions and IRQs in usermode, the existing usr_entry macro is > used to instrument the user->kernel transition. For the return to > usermode path, the ret_to_user* path is instrumented. Using the > usr_entry macro, this covers interrupts in userspace, data abort and > prefetch abort exceptions in userspace as well as undefined exceptions > in userspace (which is where FP emulation and VFP are handled.) > > For syscalls, the slow return path is covered by instrumenting the > ret_to_user path. In addition, the syscall entry point is > instrumented which covers the user->kernel transition for both fast > and slow syscalls, and an additional instrumentation point is added > for the fast syscall return path (ret_fast_syscall). > > Cc: Mats Liljegren <mats.liljeg...@enea.com> > Cc: Frederic Weisbecker <fweis...@gmail.com> > Signed-off-by: Kevin Hilman <khil...@linaro.org>
This version has been submitted to Russell's patch tracker as patch 7688[1] after making the minor change below. [...] > diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S > index 0f82098..3449d30 100644 > --- a/arch/arm/kernel/entry-armv.S > +++ b/arch/arm/kernel/entry-armv.S > @@ -396,6 +396,7 @@ ENDPROC(__pabt_svc) > #ifdef CONFIG_IRQSOFF_TRACER > bl trace_hardirqs_off > #endif > + ct_user_exit, save = 0 > .endm Removed the ',' after the macro here an elsewhere. It's harmless, but not needed and removing it makes this look like other macro usage throughout. Kevin [1] http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=7688/1 -- 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/
