From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: [RFA][PATCH 02/27] PM / Sleep: Remove ftrace_stop/start() from suspend and hibernate Date: Thu, 26 Jun 2014 12:52:23 -0400 Message-ID: <20140626165848.128028586@goodmis.org> References: <20140626165221.736847419@goodmis.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.226]:36024 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1758220AbaFZRGG (ORCPT ); Thu, 26 Jun 2014 13:06:06 -0400 Content-Disposition: inline; filename=0002-PM-Sleep-Remove-ftrace_stop-start-from-suspend-and-h.patch Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Thomas Gleixner , Masami Hiramatsu , "H. Peter Anvin" , linux-arch@vger.kernel.org, "Rafael J. Wysocki" , Jiri Kosina , Josh Poimboeuf From: "Steven Rostedt (Red Hat)" ftrace_stop() and ftrace_start() were added to the suspend and hibernate process because there was some function within the work flow that caused the system to reboot if it was traced. This function has recently been found (restore_processor_state()). Now there's no reason to disable function tracing while we are going into suspend or hibernate, which means that being able to trace this will help tremendously in debugging any issues with suspend or hibernate. This also means that the ftrace_stop/start() functions can be removed and simplify the function tracing code a bit. Signed-off-by: Steven Rostedt --- kernel/power/hibernate.c | 6 ------ kernel/power/suspend.c | 2 -- 2 files changed, 8 deletions(-) diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 49e0a20fd010..ca7b1906c6c8 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -365,7 +365,6 @@ int hibernation_snapshot(int platform_mode) } suspend_console(); - ftrace_stop(); pm_restrict_gfp_mask(); error = dpm_suspend(PMSG_FREEZE); @@ -391,7 +390,6 @@ int hibernation_snapshot(int platform_mode) if (error || !in_suspend) pm_restore_gfp_mask(); - ftrace_start(); resume_console(); dpm_complete(msg); @@ -494,7 +492,6 @@ int hibernation_restore(int platform_mode) pm_prepare_console(); suspend_console(); - ftrace_stop(); pm_restrict_gfp_mask(); error = dpm_suspend_start(PMSG_QUIESCE); if (!error) { @@ -502,7 +499,6 @@ int hibernation_restore(int platform_mode) dpm_resume_end(PMSG_RECOVER); } pm_restore_gfp_mask(); - ftrace_start(); resume_console(); pm_restore_console(); return error; @@ -529,7 +525,6 @@ int hibernation_platform_enter(void) entering_platform_hibernation = true; suspend_console(); - ftrace_stop(); error = dpm_suspend_start(PMSG_HIBERNATE); if (error) { if (hibernation_ops->recover) @@ -573,7 +568,6 @@ int hibernation_platform_enter(void) Resume_devices: entering_platform_hibernation = false; dpm_resume_end(PMSG_RESTORE); - ftrace_start(); resume_console(); Close: diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 4dd8822f732a..f6623da034d8 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -248,7 +248,6 @@ static int suspend_enter(suspend_state_t state, bool *wakeup) goto Platform_wake; } - ftrace_stop(); error = disable_nonboot_cpus(); if (error || suspend_test(TEST_CPUS)) goto Enable_cpus; @@ -275,7 +274,6 @@ static int suspend_enter(suspend_state_t state, bool *wakeup) Enable_cpus: enable_nonboot_cpus(); - ftrace_start(); Platform_wake: if (need_suspend_ops(state) && suspend_ops->wake) -- 2.0.0