Re: [PATCH] arm64: smp: Update the topology masks before calling CPU_STARTING notifiers

From: Rohit Vaswani
Date: Fri Aug 15 2014 - 19:12:26 EST

On 8/15/2014 3:43 AM, Will Deacon wrote:
On Wed, Aug 13, 2014 at 02:11:09AM +0100, Rohit Vaswani wrote:
Currently, the CPU_STARTING notifiers would observe an incorrect sibling
mask since the notifier chain is called before the topology masks are updated
for the new cpu.
Update the topology masks before calling the notifier chain to fix this

Signed-off-by: Rohit Vaswani <rvaswani@xxxxxxxxxxxxxx>
arch/arm/kernel/smp.c | 4 ++--
arch/arm64/kernel/smp.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 7c4fada..0e2237c 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -363,12 +363,12 @@ asmlinkage void secondary_start_kernel(void)
if (smp_ops.smp_secondary_init)
+ smp_store_cpu_info(cpu);
- smp_store_cpu_info(cpu);
Hmm, smp_store_cpu_info takes a copy of loops_per_jiffy. Are you sure it's
safe to move the call before calibrate_delay?

Right! - I had looked at the arm64 version . I checked for arm32 now and I think we should be
safe to move calibrate_delay before the smp_store_cpu_info and I can push a v2 version if
there are no concerns. I did not see calibrate_delay having any dependency for cpu_starting notifiers.


Rohit Vaswani

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