On Mon, Nov 18, 2024 at 01:25:01PM -0500, Steven Rostedt wrote: > On Wed, 23 Oct 2024 19:27:03 +0300 > Mike Rapoport <rppt@xxxxxxxxxx> wrote: > > > From: "Mike Rapoport (Microsoft)" <rppt@xxxxxxxxxx> > > > > Hi, > > > > This is an updated version of execmem ROX caches. > > > > FYI, I booted a kernel before and after applying these patches with my > change: > > https://lore.kernel.org/20241017113105.1edfa943@xxxxxxxxxxxxxxxxxx > > Before these patches: > > # cat /sys/kernel/tracing/dyn_ftrace_total_info > 57695 pages:231 groups: 9 > ftrace boot update time = 14733459 (ns) > ftrace module total update time = 449016 (ns) > > After: > > # cat /sys/kernel/tracing/dyn_ftrace_total_info > 57708 pages:231 groups: 9 > ftrace boot update time = 47195374 (ns) > ftrace module total update time = 592080 (ns) > > Which caused boot time to slowdown by over 30ms. That may not seem like > much, but we are very concerned about boot time and are fighting every ms > we can get. Hmm, looks like this change was lost in rebase :/ @Andrew, should I send it as a patch on top of mm-stable? diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 8da0e66ca22d..859902dd06fc 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -111,17 +111,22 @@ static int ftrace_verify_code(unsigned long ip, const char *old_code) */ static int __ref ftrace_modify_code_direct(unsigned long ip, const char *old_code, - const char *new_code) + const char *new_code, struct module *mod) { int ret = ftrace_verify_code(ip, old_code); if (ret) return ret; /* replace the text with the new text */ - if (ftrace_poke_late) + if (ftrace_poke_late) { text_poke_queue((void *)ip, new_code, MCOUNT_INSN_SIZE, NULL); - else + } else if (!mod) { text_poke_early((void *)ip, new_code, MCOUNT_INSN_SIZE); + } else { + mutex_lock(&text_mutex); + text_poke((void *)ip, new_code, MCOUNT_INSN_SIZE); + mutex_unlock(&text_mutex); + } return 0; } @@ -142,7 +147,7 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long ad * just modify the code directly. */ if (addr == MCOUNT_ADDR) - return ftrace_modify_code_direct(ip, old, new); + return ftrace_modify_code_direct(ip, old, new, mod); /* * x86 overrides ftrace_replace_code -- this function will never be used @@ -161,7 +166,7 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) new = ftrace_call_replace(ip, addr); /* Should only be called when module is loaded */ - return ftrace_modify_code_direct(rec->ip, old, new); + return ftrace_modify_code_direct(rec->ip, old, new, NULL); } /* > -- Steve -- Sincerely yours, Mike.
