From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Date: Mon, 26 Jun 2017 22:17:49 +0000 Subject: [PATCH] sh/ftrace: Remove only user of ftrace_arch_read_dyn_info() Message-Id: <20170626181749.2ce954d1@gandalf.local.home> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Yoshinori Sato , Rich Felker Cc: linux-sh@vger.kernel.org, LKML I noticed that there's only one user of ftrace_arch_read_dyn_info(). That was used a while ago during the NMI updating in x86, and superh copied it to implement its version of handling NMIs during stop_machine(). But that is a debug feature, and this code hasn't been touched since 2009. Also, x86 no longer does the ftrace updates with stop_machine() and instead uses breakpoints. If superh needs to modify its code, it should implement the breakpoint conversion, and remove stop_machine(). Which also gets rid of the NMI issue. Anyway, I want to nuke ftrace_arch_read_dyn_info() and this gets rid of the one user, which is for an arch that shouldn't need it anymore. Signed-off-by: Steven Rostedt --- [ With acks from the SUPERH maintainers, I can pull this through my own tree. ] diff --git a/arch/sh/kernel/ftrace.c b/arch/sh/kernel/ftrace.c index 5378397..d18724d 100644 --- a/arch/sh/kernel/ftrace.c +++ b/arch/sh/kernel/ftrace.c @@ -96,19 +96,6 @@ static int mod_code_status; /* holds return value of text write */ static void *mod_code_ip; /* holds the IP to write to */ static void *mod_code_newcode; /* holds the text to write to the IP */ -static unsigned nmi_wait_count; -static atomic_t nmi_update_count = ATOMIC_INIT(0); - -int ftrace_arch_read_dyn_info(char *buf, int size) -{ - int r; - - r = snprintf(buf, size, "%u %u", - nmi_wait_count, - atomic_read(&nmi_update_count)); - return r; -} - static void clear_mod_flag(void) { int old = atomic_read(&nmi_running); @@ -144,7 +131,6 @@ void arch_ftrace_nmi_enter(void) if (atomic_inc_return(&nmi_running) & MOD_CODE_WRITE_FLAG) { smp_rmb(); ftrace_mod_code(); - atomic_inc(&nmi_update_count); } /* Must have previous changes seen before executions */ smp_mb(); @@ -165,8 +151,6 @@ static void wait_for_nmi_and_set_mod_flag(void) do { cpu_relax(); } while (atomic_cmpxchg(&nmi_running, 0, MOD_CODE_WRITE_FLAG)); - - nmi_wait_count++; } static void wait_for_nmi(void) @@ -177,8 +161,6 @@ static void wait_for_nmi(void) do { cpu_relax(); } while (atomic_read(&nmi_running)); - - nmi_wait_count++; } static int From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752148AbdFZWRx (ORCPT ); Mon, 26 Jun 2017 18:17:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:58174 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751465AbdFZWRw (ORCPT ); Mon, 26 Jun 2017 18:17:52 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1B3132170D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=rostedt@goodmis.org Date: Mon, 26 Jun 2017 18:17:49 -0400 From: Steven Rostedt To: Yoshinori Sato , Rich Felker Cc: linux-sh@vger.kernel.org, LKML Subject: [PATCH] sh/ftrace: Remove only user of ftrace_arch_read_dyn_info() Message-ID: <20170626181749.2ce954d1@gandalf.local.home> X-Mailer: Claws Mail 3.14.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I noticed that there's only one user of ftrace_arch_read_dyn_info(). That was used a while ago during the NMI updating in x86, and superh copied it to implement its version of handling NMIs during stop_machine(). But that is a debug feature, and this code hasn't been touched since 2009. Also, x86 no longer does the ftrace updates with stop_machine() and instead uses breakpoints. If superh needs to modify its code, it should implement the breakpoint conversion, and remove stop_machine(). Which also gets rid of the NMI issue. Anyway, I want to nuke ftrace_arch_read_dyn_info() and this gets rid of the one user, which is for an arch that shouldn't need it anymore. Signed-off-by: Steven Rostedt --- [ With acks from the SUPERH maintainers, I can pull this through my own tree. ] diff --git a/arch/sh/kernel/ftrace.c b/arch/sh/kernel/ftrace.c index 5378397..d18724d 100644 --- a/arch/sh/kernel/ftrace.c +++ b/arch/sh/kernel/ftrace.c @@ -96,19 +96,6 @@ static int mod_code_status; /* holds return value of text write */ static void *mod_code_ip; /* holds the IP to write to */ static void *mod_code_newcode; /* holds the text to write to the IP */ -static unsigned nmi_wait_count; -static atomic_t nmi_update_count = ATOMIC_INIT(0); - -int ftrace_arch_read_dyn_info(char *buf, int size) -{ - int r; - - r = snprintf(buf, size, "%u %u", - nmi_wait_count, - atomic_read(&nmi_update_count)); - return r; -} - static void clear_mod_flag(void) { int old = atomic_read(&nmi_running); @@ -144,7 +131,6 @@ void arch_ftrace_nmi_enter(void) if (atomic_inc_return(&nmi_running) & MOD_CODE_WRITE_FLAG) { smp_rmb(); ftrace_mod_code(); - atomic_inc(&nmi_update_count); } /* Must have previous changes seen before executions */ smp_mb(); @@ -165,8 +151,6 @@ static void wait_for_nmi_and_set_mod_flag(void) do { cpu_relax(); } while (atomic_cmpxchg(&nmi_running, 0, MOD_CODE_WRITE_FLAG)); - - nmi_wait_count++; } static void wait_for_nmi(void) @@ -177,8 +161,6 @@ static void wait_for_nmi(void) do { cpu_relax(); } while (atomic_read(&nmi_running)); - - nmi_wait_count++; } static int