On Thu, Jul 01, 2021 at 08:24:32PM +0530, Neeraj Upadhyay wrote:
>
>
> On 6/30/2021 7:38 PM, Liu Song wrote:
> > From: Liu Song <liu.song11@xxxxxxxxxx>
> >
> > In rcu, most codes have used per_cpu_ptr to obtain per_cpu variable
> > pointers. This patch adjusts a few codes that have not done so.
> >
>
> Minor: Can we also add below statement?
> "This patch doesn't introduce any functional change."
>
> > Signed-off-by: Liu Song <liu.song11@xxxxxxxxxx>
Applied with the usual wordsmithing, including adding words to this
effect, so thank you all! I removed the obsolete chunk that Neeraj
pointed out as well.
Please take a look and check to see if all is well.
Thanx, Paul
------------------------------------------------------------------------
commit 9a6b5a10785f4d9b4f073736e6648fa3851882bd
Author: Liu Song <liu.song11@xxxxxxxxxx>
Date: Wed Jun 30 22:08:02 2021 +0800
rcu: Use per_cpu_ptr to get the pointer of per_cpu variable
There are a few remaining locations in kernel/rcu that still use
"&per_cpu()". This commit replaces them with "per_cpu_ptr(&)", and does
not introduce any functional change..
Reviewed-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
Reviewed-by: Neeraj Upadhyay <neeraju@xxxxxxxxxxxxxx>
Signed-off-by: Liu Song <liu.song11@xxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index f9f52daacd1c..806160c44b17 100644
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -923,7 +923,7 @@ static void trc_read_check_handler(void *t_in)
// Allow future IPIs to be sent on CPU and for task.
// Also order this IPI handler against any later manipulations of
// the intended task.
- smp_store_release(&per_cpu(trc_ipi_to_cpu, smp_processor_id()), false); // ^^^
+ smp_store_release(per_cpu_ptr(&trc_ipi_to_cpu, smp_processor_id()), false); // ^^^
smp_store_release(&texp->trc_ipi_to_cpu, -1); // ^^^
}
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index a627a200a5ae..f42b98af3ed3 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1290,7 +1290,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp)
*/
jtsq = READ_ONCE(jiffies_to_sched_qs);
ruqp = per_cpu_ptr(&rcu_data.rcu_urgent_qs, rdp->cpu);
- rnhqp = &per_cpu(rcu_data.rcu_need_heavy_qs, rdp->cpu);
+ rnhqp = per_cpu_ptr(&rcu_data.rcu_need_heavy_qs, rdp->cpu);
if (!READ_ONCE(*rnhqp) &&
(time_after(jiffies, rcu_state.gp_start + jtsq * 2) ||
time_after(jiffies, rcu_state.jiffies_resched) ||
diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
index a8d0fcf0826f..677ee3d8671b 100644
--- a/kernel/rcu/tree_stall.h
+++ b/kernel/rcu/tree_stall.h
@@ -351,7 +351,7 @@ static void rcu_dump_cpu_stacks(void)
static void print_cpu_stall_fast_no_hz(char *cp, int cpu)
{
- struct rcu_data *rdp = &per_cpu(rcu_data, cpu);
+ struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);
sprintf(cp, "last_accelerate: %04lx/%04lx dyntick_enabled: %d",
rdp->last_accelerate & 0xffff, jiffies & 0xffff,
