On Fri, Sep 25, 2020 at 08:20:00AM -0700, Guenter Roeck wrote: > On Tue, Sep 15, 2020 at 12:32:01PM +0200, Peter Zijlstra wrote: > > The C3 BusMaster idle code takes lock in a number of places, some deep > > inside the ACPI code. Instead of wrapping it all in RCU_NONIDLE, have > > the driver take over RCU-idle duty and avoid flipping RCU state back > > and forth a lot. > > > > ( by marking 'C3 && bm_check' as RCU_IDLE, we _must_ call enter_bm() for > > that combination, otherwise we'll loose RCU-idle, this requires > > shuffling some code around ) > > > > Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> > > ia64:defconfig: > > ERROR: modpost: "rcu_idle_enter" [drivers/acpi/processor.ko] undefined! > ERROR: modpost: "rcu_idle_exit" [drivers/acpi/processor.ko] undefined! > > I realize that this has already been reported more than a week ago, with > no visible reaction. Another problem introduced in the same file, resulting > in > > drivers/acpi/processor_idle.c: In function 'lapic_timer_needs_broadcast': > drivers/acpi/processor_idle.c:179:1: warning: > no return statement in function returning non-void > > may cause ia64 boot problems since a non-zero return value will trigger > a function call. AFAICS that is not supposed to happen on ia64. > > This makes me wonder - if no one cares about buiding (much less running) > ia64 images with the upstream kernel, is it possibly time to remove it ? Rafael is taking a fix up his cpuidle tree: https://lkml.kernel.org/lkml/CAJZ5v0jVerU92WxL4qCoU6NC0KCyszmRNhpL3tu5LYtMqALd9A@xxxxxxxxxxxxxx/ Thanx, Paul
