Quoting Douglas Anderson (2023-08-22 14:26:57) > As per the (somewhat recent) comment before the definition of > `__cpuidle`, the tag is like `noinstr` but also marks a function so it > can be identified by cpu_in_idle(). Let'a add this.
s/Let'a/Let's/ Maybe also define "this" to be "Let's add these markings to arm64 cpuidle functions". > > After doing this then when we dump stack traces of all processors > using nmi_cpu_backtrace() then instead of getting useless backtraces > we get things like: Sorry, this sentence is really hard for me to read. Perhaps: With this change we get useful backtraces like: NMI backtrace for cpu N skipped: idling at cpu_do_idle+0x94/0x98 instead of useless backtraces when dumping all processors using nmi_cpu_backtrace(). > > NMI backtrace for cpu N skipped: idling at cpu_do_idle+0x94/0x98 > > NOTE: this patch won't make cpu_in_idle() work perfectly for arm64, > but it doesn't hurt and does catch some cases. Specifically an example > that wasn't caught in my testing looked like this: I wonder if it improves locality of cpu idle code as well by moving the functions to the idle text section so any branch targets are closer. > > gic_cpu_sys_reg_init+0x1f8/0x314 > gic_cpu_pm_notifier+0x40/0x78 > raw_notifier_call_chain+0x5c/0x134 > cpu_pm_notify+0x38/0x64 > cpu_pm_exit+0x20/0x2c > psci_enter_idle_state+0x48/0x70 > cpuidle_enter_state+0xb8/0x260 > cpuidle_enter+0x44/0x5c > do_idle+0x188/0x30c > > Acked-by: Mark Rutland <mark.rutl...@arm.com> > Signed-off-by: Douglas Anderson <diand...@chromium.org> Reviewed-by: Stephen Boyd <swb...@chromium.org> _______________________________________________ Kgdb-bugreport mailing list Kgdb-bugreport@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport
