sh/ftrace: Remove only user of ftrace_arch_read_dyn_info() (fbb789f0) · Commits · 戴 / test

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

+0 −18

Original line number	Diff line number	Diff line
		@@ -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

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