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? That is, it doesn't need a stable tag? -- Steve
