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From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Yoshinori Sato <ysato@users.sourceforge.jp>,
	Rich Felker <dalias@libc.org>,
	linux-sh@vger.kernel.org
Subject: [for-next][PATCH 07/12] sh/ftrace: Remove only user of ftrace_arch_read_dyn_info()
Date: Thu, 29 Jun 2017 20:38:38 -0400	[thread overview]
Message-ID: <20170630004022.682713479@goodmis.org> (raw)
In-Reply-To: 20170630003831.946074263@goodmis.org

[-- Attachment #1: 0007-sh-ftrace-Remove-only-user-of-ftrace_arch_read_dyn_i.patch --]
[-- Type: text/plain, Size: 2471 bytes --]

From: Steven Rostedt <rostedt@goodmis.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.

Link: http://lkml.kernel.org/r/20170626181749.2ce954d1@gandalf.local.home

Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: linux-sh@vger.kernel.org
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 arch/sh/kernel/ftrace.c | 18 ------------------
 1 file changed, 18 deletions(-)

diff --git a/arch/sh/kernel/ftrace.c b/arch/sh/kernel/ftrace.c
index 53783978162e..d18724d186f3 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
-- 
2.10.2

  parent reply	other threads:[~2017-06-30  0:40 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-06-30  0:38 [for-next][PATCH 00/12] tracing: More updates for 4.13 Steven Rostedt
2017-06-30  0:38 ` [for-next][PATCH 01/12] ftrace: Add missing comment for FTRACE_OPS_FL_RCU Steven Rostedt
2017-06-30  0:38 ` [for-next][PATCH 02/12] tracing: Show address when function names are not found Steven Rostedt
2017-06-30  0:38 ` [for-next][PATCH 03/12] ftrace: Add :mod: caching infrastructure to trace_array Steven Rostedt
2017-06-30  0:38 ` [for-next][PATCH 04/12] ftrace: Have the cached module list show in set_ftrace_filter Steven Rostedt
2017-06-30  0:38 ` [for-next][PATCH 05/12] ftrace: Implement cached modules tracing on module load Steven Rostedt
2017-06-30  0:38 ` [for-next][PATCH 06/12] ftrace: Have cached module filters be an active filter Steven Rostedt
2017-06-30  0:38 ` Steven Rostedt [this message]
2017-06-30  0:38 ` [for-next][PATCH 08/12] ftrace: Remove unused function ftrace_arch_read_dyn_info() Steven Rostedt
2017-06-30  0:38 ` [for-next][PATCH 09/12] ftrace: Decrement count for dyn_ftrace_total_info file Steven Rostedt
2017-06-30  0:38 ` [for-next][PATCH 10/12] tracing: Add support for recording tgid of tasks Steven Rostedt
2017-06-30  0:38 ` [for-next][PATCH 11/12] tracing: Add support for display of tgid in trace output Steven Rostedt
2017-06-30  0:38 ` [for-next][PATCH 12/12] ftrace: Unlock hash mutex on failed allocation in process_mod_list() Steven Rostedt

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