On Tue, 4 Dec 2018 at 23:33, Steven Rostedt <rost...@goodmis.org> wrote: > > On Tue, 4 Dec 2018 20:40:44 +0100 > Anders Roxell <anders.rox...@linaro.org> wrote: > > > When running in qemu on an kernel built with allmodconfig and debug > > options (in particular kcov and ubsan) enabled, ftrace_replace_code > > function call take minutes. The ftrace selftest calls > > ftrace_replace_code to look >40000 through > > ftrace_make_call/ftrace_make_nop, and these end up calling > > __aarch64_insn_write/aarch64_insn_patch_text_nosync. > > > > Microseconds add up because this is called in a loop for each dyn_ftrace > > record, and this triggers the softlockup watchdog unless we let it sleep > > occasionally. > > > > Rework so that we call cond_resched() if !irqs_disabled() && > > !preempt_count(). > > This isn't urgent is it?
No, it is not urgent. I'm trying to get allmodconfig to boot on arm64. > That is, it doesn't need a stable tag? Also I don't think its a regression, since clearly nobody has ever been able to boot an arm64 allmodconfig kernel or anything close to that. Cheers, Anders
