[PATCH 1/3] powerpc: Don't preempt_disable() in show_cpuinfo()

[PATCH 1/3] powerpc: Don't preempt_disable() in show_cpuinfo()

[Benjamin Herrenschmidt]

This causes warnings from cpufreq mutex code. This is also
rather unnecessary and ineffective. If we really want to
prevent concurrent unplug, we could take the unplug read
lock but I don't see this being critical.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 arch/powerpc/kernel/setup-common.c | 11 -----------
 1 file changed, 11 deletions(-)

diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 9d213542a48b..8fd3a70047f1 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -242,14 +242,6 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 	unsigned short maj;
 	unsigned short min;
 
-	/* We only show online cpus: disable preempt (overzealous, I
-	 * knew) to prevent cpu going down. */
-	preempt_disable();
-	if (!cpu_online(cpu_id)) {
-		preempt_enable();
-		return 0;
-	}
-
 #ifdef CONFIG_SMP
 	pvr = per_cpu(cpu_pvr, cpu_id);
 #else
@@ -358,9 +350,6 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 #ifdef CONFIG_SMP
 	seq_printf(m, "\n");
 #endif
-
-	preempt_enable();
-
 	/* If this is the last cpu, print the summary */
 	if (cpumask_next(cpu_id, cpu_online_mask) >= nr_cpu_ids)
 		show_cpuinfo_summary(m);
-- 
2.14.3

[PATCH 2/3] powerpc: Make newline in cpuinfo unconditional

[Benjamin Herrenschmidt]

We used to not put the newline between the CPU part and the summary
part on UP kernels. This is a rather pointless ifdef so take it out.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 arch/powerpc/kernel/setup-common.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 8fd3a70047f1..c1df4ba0094c 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -346,10 +346,8 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 		   loops_per_jiffy / (500000/HZ),
 		   (loops_per_jiffy / (5000/HZ)) % 100);
 #endif
-
-#ifdef CONFIG_SMP
 	seq_printf(m, "\n");
-#endif
+
 	/* If this is the last cpu, print the summary */
 	if (cpumask_next(cpu_id, cpu_online_mask) >= nr_cpu_ids)
 		show_cpuinfo_summary(m);
-- 
2.14.3

[PATCH 3/3] powerpc: Cosmetic cleanup of cpuinfo_op

[Benjamin Herrenschmidt]

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 arch/powerpc/kernel/setup-common.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index c1df4ba0094c..9f9524bdd3f1 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -377,10 +377,10 @@ static void c_stop(struct seq_file *m, void *v)
 }
 
 const struct seq_operations cpuinfo_op = {
-	.start =c_start,
-	.next =	c_next,
-	.stop =	c_stop,
-	.show =	show_cpuinfo,
+	.start	= c_start,
+	.next	= c_next,
+	.stop	= c_stop,
+	.show	= show_cpuinfo,
 };
 
 void __init check_for_initrd(void)
-- 
2.14.3

Re: [1/3] powerpc: Don't preempt_disable() in show_cpuinfo()

[Michael Ellerman]

On Wed, 2018-01-10 at 06:10:12 UTC, Benjamin Herrenschmidt wrote:
> This causes warnings from cpufreq mutex code. This is also
> rather unnecessary and ineffective. If we really want to
> prevent concurrent unplug, we could take the unplug read
> lock but I don't see this being critical.
> 
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/349524bc0da698ec77f2057cf4a494

cheers

Re: [1/3] powerpc: Don't preempt_disable() in show_cpuinfo()

[Michael Ellerman]

On Wed, 2018-01-10 at 06:10:12 UTC, Benjamin Herrenschmidt wrote:
> This causes warnings from cpufreq mutex code. This is also
> rather unnecessary and ineffective. If we really want to
> prevent concurrent unplug, we could take the unplug read
> lock but I don't see this being critical.
> 
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/349524bc0da698ec77f2057cf4a494

cheers

Re: [2/3] powerpc: Make newline in cpuinfo unconditional

[Michael Ellerman]

On Wed, 2018-01-10 at 06:10:13 UTC, Benjamin Herrenschmidt wrote:
> We used to not put the newline between the CPU part and the summary
> part on UP kernels. This is a rather pointless ifdef so take it out.
> 
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/f5f563012a7002e64853c61d293d65

cheers

Re: [3/3] powerpc: Cosmetic cleanup of cpuinfo_op

[Michael Ellerman]

On Wed, 2018-01-10 at 06:10:14 UTC, Benjamin Herrenschmidt wrote:
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/fbadeb6bb1685f7a53869e240284ff

cheers